ENGINE CRANKS BUT WILL NOT START Probable Causes •
Diagnostic codes, event codes, and the power supply for the Electronic Control Module (ECM)
•
Air inlet heater
•
Engine shutdown switches
•
Engine speed/timing
•
Injection actuation pressure
•
Unit injectors
•
Fuel supply
•
Combustion
Recommended Actions Diagnostic Codes, Event Codes, and ECM Power Supply Certain diagnostic codes and/or event codes may prevent the engine from starting. Connect the Caterpillar Electronic Technician (ET) and check for active codes and/or for logged codes. Troubleshoot any codes that are present before b efore continuing with this procedure. Note: If Cat ET will not communicate with the ECM, the problem is most likely with the electrical
power supply to the ECM. Refer to Troubleshooting, "Electrical Power Supply Circuit - Test".
Air Inlet Heater Ensure that the air inlet heater is working properly. Ensure that the heater element is in good repair. For additional information on the air inlet heater, refer to Troubleshooting, "Air Inlet Heater Circuit Test".
Engine Shutdown Switches The engine shutdown switches should be in the RUN position. Use Cat ET to verify the status of the shutdown switches. When a shutdown occurs, the shutdown switch must be reset prior to restarting the engine. On some applications, the keyswitch must be cycled before the ECM will allow engine cranking. Allow the keyswitch power to the ECM to be in the OFF position for at least 15 seconds prior to restarting the engine. Note: If Cat ET will not communicate with the ECM, the problem is most likely with the electrical
power supply to the ECM. Refer to Troubleshooting, "Electrical Power Supply Circuit - Test".
Engine Speed/Timing 1. Crank the engine and observe the engine speed on the Cat ET status screen. If Cat ET indicates zero rpm, refer to Troubleshooting, "Engine Speed/Timing Sensor Circuit - Test".
Note: Upon initial cranking, the status for engine speed may indicate that the engine speed
signal is abnormal. This message will be replaced with an engine speed once the ECM is able to calculate a speed from the signal. 2. Ensure that the timing reference gear is installed correctly. The engine will not start if the gear was installed backward. Check for proper orientation between the crankshaft and camshaft drive gears. Correct the orientation and/or replace the drive gear, if necessary. Refer to the Disassembly and Assembly for information that relates to the correct installation of the front gear train.
Injection Actuation Pressure 1. Check the engine oil level. Engine oil supplies the injection actuation pressure circuit. The engine oil must be kept at the proper level for fuel injection. 2. If service has recently been performed on the engine, air may be present in the injection actuation pressure circuit. Allow the engine to fully warm up and operate the engine under load in order to purge the air from the injection actuation pressure circuit. 3. Check the injection actuation pressure. Refer to Troubleshooting, "Injection Actuation Pressure - Test" for the correct procedure. 4. Check the operation of the injection actuation pressure control valve. Refer to Troubleshooting, "Injection Actuation Pressure Control Valve Circuit - Test" for the proper troubleshooting procedure.
Injection Actuation Pressure - Test SMCS - 1714-038 System Operation Description:
Use the steps that follow to check the operation of the HEUI fuel system. Circle the appropriate answer in the "Results" section of each test step. Complete all of the test steps that are in this procedure. Return the pages of this procedure with any of the requested parts through Caterpillar's return system.
Note: Upon initial cranking, the status for engine speed may indicate that the engine speed
signal is abnormal. This message will be replaced with an engine speed once the ECM is able to calculate a speed from the signal. 2. Ensure that the timing reference gear is installed correctly. The engine will not start if the gear was installed backward. Check for proper orientation between the crankshaft and camshaft drive gears. Correct the orientation and/or replace the drive gear, if necessary. Refer to the Disassembly and Assembly for information that relates to the correct installation of the front gear train.
Injection Actuation Pressure 1. Check the engine oil level. Engine oil supplies the injection actuation pressure circuit. The engine oil must be kept at the proper level for fuel injection. 2. If service has recently been performed on the engine, air may be present in the injection actuation pressure circuit. Allow the engine to fully warm up and operate the engine under load in order to purge the air from the injection actuation pressure circuit. 3. Check the injection actuation pressure. Refer to Troubleshooting, "Injection Actuation Pressure - Test" for the correct procedure. 4. Check the operation of the injection actuation pressure control valve. Refer to Troubleshooting, "Injection Actuation Pressure Control Valve Circuit - Test" for the proper troubleshooting procedure.
Injection Actuation Pressure - Test SMCS - 1714-038 System Operation Description:
Use the steps that follow to check the operation of the HEUI fuel system. Circle the appropriate answer in the "Results" section of each test step. Complete all of the test steps that are in this procedure. Return the pages of this procedure with any of the requested parts through Caterpillar's return system.
Left side engine view (typical component locations) (1) Injection Actuation Pressure Control Valve (IAPCV) (2) Injection actuation pressure sensor (3) J2/P2 ECM connector (4) Fuel injection pump outlet port (5) Line for low pressure oil
Test Step 1. Symptoms
The following symptoms may occur if there is a problem with the HEUI fuel system: •
The engine cranks but the engine will not start.
•
The engine runs rough.
•
The engine is erratic or unstable at idle or running.
•
Low power
The following diagnostic codes might be currently active or logged: •
164-00 High Injectuation Actuation Pressure
•
164-02 Injectuation Actuation Pressure signal irratic
•
164-11 Injectuation Actuation Pressure system fault
A. Connect the Caterpillar Electronic Technician (ET) to the service tool connector.
B. Restore the electrical power to the ECM. DO NOT START THE ENGINE. C. Print the "Lifetime Totals" and the "Configuration" screen. D. Check for active diagnostic codes. Expected Result:
There are no active diagnostic codes with the electrical power to the ECM restored while the engine is off. Results: •
OK - None of these codes are active with the electrical power to the ECM restored while the
engine is off. Proceed to Test Step 2. •
Not OK - 164-03 or 164-04 is active with the electrical power to the ECM restored while the
engine is off. Repair: Refer to Troubleshooting, "Analog Sensor Open or Short Circuit - Test". STOP •
Not OK - A 164-02 diagnostic code is active with the electrical power to the ECM restored
while the engine is off. Repair: Refer to Troubleshooting, "Injection Actuation Pressure Sensor - Test". STOP •
Not OK - 164-00 or 164-11 is active with the electrical power to the ECM restored while the
engine is off. Repair: Contact your Engine Technical Communicator (TC). STOP Test Step 2. Check the Engine Oil Level
A. Check the engine oil level. Refer to Operation and Maintenance Manual, "Engine Oil Level Check". B. If the engine oil level is low add oil to the engine. C. Try to start the engine. Expected Result:
The engine has started. Results: •
OK - The engine starts. Proceed to Test Step 9.
•
Not OK - The engine does not start. Proceed to Test Step 3.
Test Step 3. Crank the Engine and Record the Engine Data From Cat ET
Your answer indicated that the engine oil level is satisfactory. A. Crank the engine and observe the "Injection Actuation Pressure" and "Engine RPM". ________ Record the actual injection actuation pressure. ________ Record the engine speed. Expected Result:
The injection actuation pressure is above 6 MPa (870 psi). Results: •
OK - The injection actuation pressure is above 6 MPa (870 psi). Repair: The HEUI system is functioning correctly. Refer to Troubleshooting, "Engine Cranks
but Will Not Start" which is located in the "Troubleshooting " Troubleshooting without a Diagnostic Code" section. STOP •
Not OK - The injection actuation pressure is below 6 MPa (870 psi). Proceed to Test Step 4.
Test Step 4. Check the Oil Pressure at the Fuel Injection Pump Outlet Port
Locate the high pressure oil line that supplies high pressure oil to the cylinder head. Re move the oil line and install the 8T-0852 Pressure Gauge to the line or to the high pressure port at the pump. Crank the engine and record the oil pressure that is indicated on the gauge. Note: The pressure readings may vary between gauges.
________ Observed pressure reading ________ Observed RPM ________ Observed "Injection Actuation Output Percent" Expected Result:
The oil pressure is above 27.5 MPa (4000 psi). Results: •
OK - The oil pressure is above 27.5 MPa (4000 psi). Repair: Remove the pressure gauge from the engine.
Proceed to Test Step 8. •
Not OK - The oil pressure is below 27.5 MPa (4000 psi). Proceed to Test Step 5.
Test Step 5. Install a Test Plug and Recheck the Oil Pressure
A. Remove the Injection Actuation Pressure Control Valve (IAPCV). B. Install a 219-2368 Plug (DIAGNOSTIC) and 9X-1484 Seal Kit and perform the pressure test at the fuel injection pump outlet port. Crank the engine and record the results. ________ Observed pressure reading Note: If the 219-2368 Plug (DIAGNOSTIC) is not available, proceed to "Install a New
IAPCV and Check the Oil Pressure". Expected Result:
The oil pressure is above 27.5 MPa (4000 psi). Results: •
OK - The oil pressure is above 27.5 MPa (4000 psi). Repair: The HEUI pump is OK. Replace the IAPCV and recheck the oil pressure. If the
problem continues contact technical support. STOP
•
Not OK - The oil pressure is below 27.5 MPa (4000 psi). Remove the pressure gauge from
the engine. Proceed to Test Step 7. Test Step 6. Install a New IAPCV and Check the Oil Pressure Note: Use this Test Step only if the 219-2368 Plug (DIAGNOSTIC) is not available.
A. Install a new IAPCV onto the high pressure oil pump. Refer to Disassembly and Assembly, "Injection Actuation Pressure Control Valve - Remove and Install". B. Check the oil pressure at the fuel injection pump outlet port. Record the pressure reading. ________ Observed pressure reading Expected Result:
The oil pressure measures above 27.5 MPa (4000 psi). Results: •
OK - The oil pressure is above 27.5 MPa (4000 psi). Repair: The replacement of the IAPCV has corrected the problem. Remove the test
equipment from the engine. Verify that the repair has resolved the problem. STOP •
Not OK - The oil pressure is below 27.5 MPa (4000 psi). Remove the new IAPCV and
reinstall the original IAPCV. Proceed to Test Step 7. Test Step 7. Check the Fuel Injection Pump Drive Gear
A. Remove the high pressure oil pump. Refer to Disassembly and Assembly, "Unit Injector Hydraulic Pump - Remove". B. Check for any physical damage to the drive gear. C. Verify that the drive gear and the retaining bolt are properly tightened. Also verify that the pump shaft rotates freely. Expected Result:
The drive gear and the retaining bolt for the high pressure oil pump are tight. The pump shaft rotates freely. Results: •
OK - The drive gear bolt is properly tightened and the pump shaft rotates freely. Repair: Replace the high pressure oil pump. Refer to Disassembly and Assembly, "Unit
Injector Hydraulic Pump - Install". Verify that the repair has resolved the problem. If this does not fix the problem, contact technical support. STOP •
Not OK - The pump shaft does not rotate freely. Repair: Replace the high pressure oil pump. Refer to Disassembly and Assembly, "Unit
Injector Hydraulic Pump - Install". Verify that the repair has resolved the problem. If this does not fix the problem, contact technical support. STOP
•
Not OK - The drive gear bolt is loose. The pump shaft rotates freely and there is no obvious
mechanical damage that would indicate a different problem. Repair: Replace the drive gear, if necessary. Tighten the drive gear bolt. Refer to
Specifications, "Unit Injector Hydraulic Pump". Reinstall the pump. Refer to Disassembly and Assembly, "Unit Injector Hydraulic Pump - Install". Recheck the p ressure in order to ensure that the problem has been resolved.If this does not fix the problem, replace the high pressure oil pump. Verify that the repair has resolved the problem. STOP Test Step 8. Check the High Pressure Oil System for Leaks
A. Remove the valve cover and inspect the high pressure oil system for oil leaks. a. While the engine is being cranked, inspect the area around the injector bores for any signs of oil leakage. b. Inspect the spill ports of the injector for excessive oil. All six injectors should spill the same amount of oil. Expected Result:
No leaks are apparent. Results: •
OK - The high pressure oil system is not leaking. Repair: Call technical support for assistance. STOP
•
Not OK - A leak in the high pressure oil system has been found. Repair: Replace the O-ring on the injector or replace the damaged injector. Verify that the
repair has resolved the problem. STOP Test Step 9. Operate the Engine and Check for Diagnostic Codes
A. Restore the electrical power to the (engine) ECM. Start the engine. B. While the engine is running, use Cat ET to check for the following diagnostic codes: •
164-00
•
164-02
•
164-11
Place a check beside the codes that are active or logged. •
________ 164-00
•
________ 164-02
•
________ 164-11
Stop the engine. Expected Result:
None of the diagnostic codes are active.
Results: •
OK - None of the diagnostic codes that are mentioned above are active. Proceed to Test Step
10. •
Not OK - Either a 164-00 or a 164-11 is active. A 164-02 may also be active at this time.
Proceed to Test Step 10. •
Not OK - 164-02 is active, but 164-00 and 164-11 are not active at this time. Repair: Refer to Troubleshooting, "Injection Actuation Pressure Sensor - Test". STOP
Test Step 10. Evaluate the Quality of the Oil
Extended oil drain intervals may affect the operation of the HEUI high pressure oil system. Refer to the Operation and Maintenance Manual, "Engine Oil" for additional information concerning proper oil change intervals. A. Check the maintenance records for the engine. Ensure that the customer has not exceeded the suggested oil change interval. Expected Result:
The customer has not exceeded the suggested oil change interval and an oil change does not need to be performed. Results: •
OK - The engine has been properly maintained. Proceed to Test Step 11.
•
Not OK - The customer has exceeded the suggested oil change interval for the engine. Repair: Perform an oil change on the engine. Refer to Operation and Maintenance Manual,
"Engine Oil and Filter - Change".Run the engine throughout the operating rpm range for 10 to 15 minutes. This will purge any trapped air or debris that is in the system. If the problem still exists or if the problem recurs in a sho rt period or time, proceed to Test Step 11. Test Step 11. Perform the "Injection Actuation Pressure Test"
A. Install 8T-0852 Pressure Gauge on the high pressure oil rail. B. Connect Cat ET to the service tool connector. C. Perform the "Injection Actuation Pressure Test" in the using Cat ET. Record the results in Table 1. Note: The "Injection Actuation Pressure Test" can be u sed to vary the injection actuation
pressure. The test adjusts the oil pressure in steps. Some versions of Cat ET may have three steps in the test and some versions of Cat ET may have four steps in the test. Table 1 Step
Manual pressure gauge
Cat ET
Difference
1 2 3 4 Expected Result:
The pressure that is measured with the pressure gaug e for each step and the pressure that is displayed on Cat ET for each step are within 1379 kPa (200 psi). Results: •
OK - The pressure difference is within specifications. The injection actuation pressure sensor
is operating properly. Proceed to Test Step 12. •
Not OK - The pressure difference is not within specifications. Repair: The injection actuation pressure sensor may be faulty. Replace the sensor and repeat
this test step. If the problem still exists, reinstall the original sensor and proceed to T est Step 12. Test Step 12. Perform the "Injection Actuation Pressure Test" at both Low Idle and at High Idle
Start the engine. Perform the "Injection Actuation Pressure Test" at low idle and at high idle. Record the results in Table 2. Table 2 Low Idle Step
Actual injection pressure from Cat
"Injection Pressure Percentage Output" from
ET
Cat ET
1 2 3 4 High Idle Step
Actual injection pressure from Cat
"Injection Pressure Percentage Output" from
ET
Cat ET
1 2 3 4 Expected Result:
The "Injection Actuation Pressure Output" is between 0 percent and 65 percent. Results: •
OK - The "Injection Actuation Pressure Output" is within specifications. Repair: Call technical support for assistance. STOP
•
Not OK - The "Injection Actuation Pressure Output" is not within specifications. Proceed to
Test Step 13. Test Step 13. Install a New IAPCV and Retest the System
Install a new IAPCV and perform the "Injection Actuation Pressure Test" at low idle and at high idle. Record the results in Table 3. Table 3 Low Idle Step
Actual injection pressure from Cat
"Injection Pressure Percentage Output" from
ET
Cat ET
1 2 3 4 High Idle Step
1 2
Actual injection pressure from Cat
"Injection Pressure Percentage Output" from
ET
Cat ET
3 4 Expected Result:
The "Injection Actuation Pressure Output" is between 0 percent and 65 percent. Results: •
OK - The "Injection Actuation Pressure Output" is within specifications. Repair: The replacement of the IAPCV corrected the problem. Run the engine under normal
operating conditions in order to verify that the original problem has been resolved. STOP •
Not OK - The "Injection Actuation Pressure Output" is not within specifications. Reinstall the
original IAPCV. Proceed to Test Step 14. Test Step 14. Remove the IAPCV and Check the Oil Pressure
A. Remove the IAPCV. Refer to Disassembly and Assembly, "Injection Actuation Pressure Control Valve - Remove and Install". B. Replace the IAPCV with a 219-2368 Plug (DIAGNOSTIC) and 9X-1484 Seal Kit . C. Locate the high pressure oil line that supplies high pressure oil to the cylinder head. Remove the oil line and install the 8T-0852 Pressure Gauge to the line or to the high pressure port at the pump. Crank the engine and record the oil pressure that is indicated on the gauge. Note: The pressure readings may vary between gauges.
________ Observed pressure reading ________ Observed RPM Expected Result:
The oil pressure is above 27.5 MPa (4000 psi). Results: •
OK - The oil pressure is above 27.5 MPa (4000 psi). The high pressure oil pump is operating
correctly. Proceed to Test Step 16. •
Not OK - The oil pressure is below 27.5 MPa (4000 psi). Repair: The high pressure oil pump may be faulty. Remove the pressure gauge from the
engine. Proceed to Test Step 15. Test Step 15. Check the Fuel Injection Pump Drive Gear
A. Remove the high pressure oil pump. Refer to Disassembly and Assembly, "Unit Injector Hydraulic Pump - Remove". B. Check for any physical damage to the drive gear.
C. Verify that the drive gear and the retaining bolt are properly tightened. Also verify that the pump shaft rotates freely. Expected Result:
The drive gear and the retaining bolt for the high pressure oil pump are tight. The pump shaft rotates freely. Results: •
OK - The drive gear bolt is properly tightened and the pump shaft rotates freely. Repair: Replace the high pressure oil pump. Refer to Disassembly and Assembly, "Unit
Injector Hydraulic Pump - Install". Verify that the repair resolved the problem.If this does not fix the problem, contact technical support. STOP •
Not OK - The pump shaft does not rotate freely. Repair: Replace the high pressure oil pump. Refer to Disassembly and Assembly, "Unit
Injector Hydraulic Pump - Install". Verify that the repair resolved the problem.If this does not fix the problem, contact technical support. STOP •
Not OK - The drive gear bolt is loose. The pump shaft rotates freely and there is no obvious
mechanical damage that would indicate a different problem. Repair: Replace the drive gear, if necessary. Tighten the drive gear bolt. Refer to
Specifications, "Unit Injector Hydraulic Pump". Reinstall the pump. Refer to Disassembly and Assembly, "Unit Injector Hydraulic Pump - Install". Check the pressure in order to ensure that the problem has been resolved.If this does not fix the problem, replace the high pressure oil pump. Verify that the repair has resolved the problem. STOP Test Step 16. Check the High Pressure Oil System for Leaks
A. Remove the valve cover and inspect the high pressure oil system for oil leaks. a. While the engine is being cranked, inspect the area around the injector bores for any signs of oil leakage. b. Inspect the spill ports of the injector for excessive oil. All six injectors should spill the same amount of oil. Expected Result:
No leaks are apparent. Results: •
OK - The high pressure oil system does not appear to be leaking. Repair: Call technical support for assistance. STOP
•
Not OK - A leak has been detected in the high pressure oil system.
Repair: Replace the O-ring on the injector or replace the damaged injector. Verify that the
repair has resolved the problem. STOP
Unit Injectors Perform the "Injector Solenoid Test" on Cat ET in order to determine if each of the injector solenoids are being energized by the ECM. Refer to Troubleshooting, "Injector Solenoid Circuit - Test" for additional information.
Fuel Supply 1. Visually check the fuel level in the fuel tank. Do not rely on the fuel gauge only. If necessary, add fuel to the fuel tank. If the engine has been run out of fuel, it will be necessary to purge the air from the fuel system. Refer to Operation and Maintenance Manual, "Fuel System Prime" for the correct procedure. 2. Check the fuel lines for the following problems: restrictions, collapsed lines and pinched lines. If problems are found with the fuel lines, repair the lines and/or replace the lines. 3. Check the fuel tank for debris or foreign objects which may block the fuel supply.
NOTICE
Do not crank the engine continuously for more than 30 seconds. Allow the starting motor to cool for two minutes before cranking the engine again.
4. Prime the fuel system if any of the following procedures have been performed: o
Replacement of the fuel filters
o
Service on the low pressure fuel supply circuit
o
Replacement of unit injectors
Note: A sight glass in the low pressure supply line is helpful in diagnosing air in the fuel.
Refer to Testing and Adjusting for more information. 5. Check fuel quality. Cold weather adversely affects the characteristics of the fuel. Refer to the applicable Operation and Maintenance Manual for information on improving the characteristics of the fuel during cold weather o peration. 6. Check the filtered fuel pressure while the engine is being cranked. Refer to Testing and Adjusting for the correct pressure values. If the fuel pressure is low, replace the fuel filters. If the fuel pressure is still low, check the following items: fuel transfer pump, fuel transfer pump
coupling and fuel pressure regulating valve. Refer to Testing and Adjusting for more information.
Combustion Check for combustion problems.
Air Inlet Heater Circuit - Test System Operation Description:
Use this procedure to troubleshoot any suspect problems with the air inlet heater circuit. This procedure covers the following diagnostic codes: •
617-05 Air Inlet Heater Relay open/current below normal
•
617-06 Air Inlet Heater Relay grounded/current above norm
The air inlet heater improves the engine's ability to start when the engine is cold. The air inlet heater also reduces white smoke when the engine is cold. The Electronic Control Module (ECM) controls the operation o f the air inlet heater via the air inlet heater relay. The operation of the air inlet heater is determined by the following cycles: Power Up Cycle - The air inlet heater is turned on for two seconds after the ECM is first powered up.
This will happen regardless of temperatures and engine speed. Preheat Cycle - If the "SUM" of the coolant temperature and the inlet manifold air temperature is
less than 25 °C (109 °F), then the heater will remain on up to 30 seconds. If the engine speed is zero after 30 seconds, the heater is turned off regardless of the temperature. Crank Cycle - If the "SUM" of the coolant temperature and the inlet manifold air temperature is still
less than 25 °C (109 °F), the air inlet heater will remain on while the engine is being cranked. Running Cycle - If the "SUM" of the coolant temperature and the inlet manifold air temperature is
less than 35 °C (127 °F), then the air inlet heater will remain on for seven minutes. Postheat Cycle - The air inlet heater is cycled on and off for an additional 13 minutes if the "SUM"
of the coolant temperature and the inlet manifold air temperature is still less than 35 °C (127 °F). The air inlet heater will turn on for ten seconds and the air inlet heater will turn off for ten seconds. Note: When you convert the "SUM" of two temperatures that are in degrees Celsius, the resulting value in degrees Fahrenheit will be incorrect. The two temperatures must be converted prior to the addition of the two values. •
Convert the reading for the coolant temperature from degrees Celsius to degrees Fahrenheit.
•
Convert the reading for the inlet manifold air temperature from degrees Celsius to degrees Fahrenheit.
•
Add the two conversions together in order to arrive at the correct conversion for the sum in degrees Fahrenheit. Refer to the example that is in Table 1. Table 1 Example Reading
°C
°F
Coolant Temperature
15 °C
59 °F
Inlet Manifold Air Temperature
10 °C
50 °F
"SUM" (1)
25 °C
109 °F
(1)
The sum cannot be directly converted. The direct conversion of 25 °C is 77 °F.
Schematic of the circuit for the air inlet heater
Test Step 1. Inspect Electrical Connectors and Wiring
A. Remove power from the ECM. B.
Left side engine view (1) Air inlet heater relay (2) Connector for the air inlet heater relay (3) Air inlet heater (4) J2/P2 ECM connectors
B. Thoroughly inspect all connections for components (1) a nd (3). Also, thoroughly inspect connectors (2) and (4). Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
(P2-9) Air inlet heater −
(P2-12) Air inlet heater +
C. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the air inlet heater. D. Check the allen head screw at each ECM connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values. E. Check the harness and wiring for abrasion and for pinch points from the air inlet heater back to the ECM and from the air inlet heater back to the battery. Expected Result:
All connectors, pins and sockets are completely coupled and/or inserted and the harness and wiring are free of corrosion, of abrasion and of pinch points.
Results: •
OK - The harness and connectors appear to be OK. Proceed to Test Step 2.
•
Not OK - A problem has been found with a connector and/or wiring. Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that
all of the seals are properly in place and ensure that the connectors are completely coupled. Verify that the repair eliminates the problem. STOP Test Step 2. Check for Active Diagnostic Codes
A. Connect Caterpillar Electronic Technician (ET) to the service tool connector. B. Restore power to the ECM. C. Start the "Air Inlet Heater Override" on Cat ET and observe the test lamp. Note: Do not leave the "Air Inlet Heater Override" ON. Avoid unnecessary cycling of the a ir
inlet heater in order to prevent the battery from discharging. The "Air Inlet Heater Override" has a one minute timer that disables the test when the time expires. D. Stop the "Air Inlet Heater Override". E. Remove power from the ECM. Expected Result:
One of the following diagnostic codes is active: •
617-05
•
617-06
Results: •
617-05 is Active - The ECM detects an open circuit between the air inlet heater relay and the
ECM. Proceed to Test Step 3. •
617-06 is Active - The ECM detects a short circuit between the air inlet heater relay and the
ECM. Proceed to Test Step 4. •
No Codes are Active - There are no active diagnostic codes for the air inlet heater relay.
Proceed to Test Step 6. Test Step 3. Check for an Open Circuit in the Air Inlet Heater Relay's Control Circuit
Small terminals for the air inlet heater relay's control circuit (typical example)
A. Disconnect the wires from the small terminals for the air inlet heater relay's control circuit. B. Install a test lamp across the wires. C. Restore power to the ECM. D. Start the "Air Inlet Heater Override" on Cat ET and observe the test lamp. Note: The "Air Inlet Heater Override" has a one minute timer in order to disable the test when
the time expires. E. Stop the "Air Inlet Heater Override". F. Remove power from the ECM. Expected Result:
The test lamp illuminated while the override was active. Results: •
OK - The test lamp illuminated while the override was active. The open circuit is in the relay. Repair: Replace the air inlet heater relay. Clear any diagnostic codes. Verify that the problem
is resolved. STOP •
Not OK - The test lamp did not illuminate while the override was active. Leave the wires
disconnected from the small terminals of the relay. Proceed to Test Step 5. Test Step 4. Check for a Short Circuit to the Coil of the Air Inlet Heater Relay
Small terminals for the air inlet heater relay's control circuit (typical example)
A. Disconnect the wires from the small terminals for the air inlet heater relay's control circuit. B. Restore power to the ECM. C. Start the "Air Inlet Heater Override" on Cat ET. Note: The "Air Inlet Heater Override" has a one minute timer in order to disable the test when
the time expires. D. Stop the "Air Inlet Heater Override". E. Remove power from the ECM. Expected Result:
The short circuit diagnostic code 06 changed to an open circuit diagnostic code 05 when the control wires to the air inlet heater relay were disconnected.
Results: •
OK - The short circuit diagnostic code changed to an open circuit diagnostic code. Repair: There is a short circuit in the air inlet heater relay. Replace the air inlet heater relay
and clear the diagnostic codes. Verify that the repair eliminates the problem. STOP •
Not OK - The short circuit diagnostic code did not change. Proceed to Test Step 5.
Test Step 5. Check the Operation of the ECM by Creating an Open and Short at the ECM Connector
A. Check the operation of the ECM by creating an open at the ECM. a. Remove power from the ECM. b. Disconnect the P2 ECM connector. Thoroughly inspect both halves of the connector for signs of corrosion and/or for moisture. c. Remove the wires for the air inlet heater relay from the P2 ECM connector. Install wire jumpers with Deutsch sockets into the sockets for the a ir inlet heater relay. Ensure that the wire jumpers are not touching any other wires. Reconnect the P2 connector. d. Restore power to the ECM. e. Start the "Air Inlet Heater Override" on Cat ET. Note: The "Air Inlet Heater Override" has a one minute timer in order to disable the
test when the time expires. A 05 diagnostic code should be active for the air inlet heater relay. f.
Remove power from the ECM.
B. Check the operation of the ECM by creating a short at the ECM. a. Install a jumper wire between the two wire jumpers for the air inlet heater relay that were installed in the previous step. b. Restore power to the ECM. c. Start the "Air Inlet Heater Override" on Cat ET. Note: The "Air Inlet Heater Override" has a one minute timer in order to disable the
test when the time expires. A 06 diagnostic code should be active for the air inlet heater relay. d. Remove power from the ECM. e. Remove the wire jumpers and reconnect ECM connector J2/P2. Expected Result:
An open circuit diagnostic code 05 is active when the wires for the air inlet heater relay are removed from the ECM connector. A short circuit diagnostic code 06 is active when the jumper wire is installed across the wires for the air inlet heater relay. Results:
•
OK - The ECM is working properly. The problem is in the wiring between the ECM and the
air inlet heater relay. Repair: Repair the wires and/or the connector. STOP •
Not OK - One of the following conditions exists: The open circuit diagnostic code 05 is not
active when the harness is disconnected. The short circuit diagnostic code 06 is not active when the jumper wire is installed. Repair: Perform the following repair:
1. Temporarily connect a spare ECM. 2. Remove all jumper wires and reconnect all connectors and wires. 3. Recheck the system for active diagnostic codes. 4. Repeat this test step. 5. If the problem is resolved with the spare ECM, reconnect the suspect ECM. 6. If the problem returns with the suspect ECM, replace the ECM. 7. Verify that the repair eliminates the problem. STOP Test Step 6. Check for Battery Voltage to the Air Inlet Heater Relay
A. Remove the wire from the +Battery side of the air inlet heater relay. B. Connect a test lamp between the wire from the +Battery side of the air inlet heater relay an d engine ground. C. Restore power to the ECM. D. Observe the test lamp. E. Remove power from the ECM. Expected Result:
The test lamp illuminated. Results: •
OK - The test lamp illuminated. Battery voltage is reaching the air inlet heater relay. Proceed
to Test Step 7. •
Not OK - The test lamp did not illuminate. Repair: Battery voltage is not reaching the relay. Ensure that the circuit breaker is not
tripped. Repair the harness from the battery to the air inlet heater relay. Verify that the repair eliminates the problem. STOP Test Step 7. Check for Voltage Output at the Air Inlet Heater Relay
A. Reconnect the wire from the +Battery to the air inlet heater relay. B. Remove the wire to the air inlet heater from the air inlet heater relay.
C. Connect a test lamp between the output terminal of the air inlet heater relay and engine ground. D. Restore power to the ECM. E. Observe the test lamp. The test lamp should not be illuminated, since the air inlet heater relay is not energized. If the test lamp is illuminated, ensure that the test lamp is connected to the output side of the air inlet heater relay. F. Run the "Air Inlet Heater Override" on Cat ET and observe the test lamp. Note: The "Air Inlet Heater Override" has a one minute timer in order to disable the test when
the time expires. G. Stop the "Air Inlet Heater Override". H. Remove power from the ECM. Expected Result:
The test lamp illuminated while the override was active. Results: •
OK - The test lamp illuminated while the override was active. The air inlet heater relay and
the +Battery connection to the air inlet heater relay are operating correctly. Proceed to Test Step 8. •
Not OK - The test lamp did not illuminate while the ov erride was active. Repair: Replace the air inlet heater relay.Verify that the repair eliminates the problem. STOP
Test Step 8. Check the Wiring Between the Air Inlet Heater Relay and the Air Inlet Heater
A. Reconnect the wire from the air inlet heater relay to the air inlet heater. B. Disconnect the wire between the air inlet heater relay and the air inlet heater from the air inlet heater. C. Connect a test lamp between the wire at the air inlet heater and engine ground. D. Restore power to the ECM. E. Run the "Air Inlet Heater Override" on Cat ET and observe the test lamp. Note: The "Air Inlet Heater Override" has a one minute timer in order to disable the test when
the time expires. F. Stop the "Air Inlet Heater Override". G. Remove power from the ECM. H. Reconnect the wire between the air inlet heater relay and the air inlet heater. Expected Result:
The test lamp illuminated while the override was active. Results: •
OK - The test lamp illuminated while the override was a ctive. The wire from the air inlet
heater relay to the air inlet heater is OK. Proceed to Test Step 9.
•
Not OK - The test lamp did not illuminate while the ov erride was active. Repair: There is an open in the wire between the air inlet heater relay and the air inlet heater.
Replace the wire. Verify that the repair eliminates the problem. STOP Test Step 9. Measure the Current through the Air Inlet Heater
A. Connect a 155-5176 AC/DC Current Probe or an equivalent inductive pickup clamp around wire between the air inlet heater relay and the air inlet heater. B. Connect the current probe to a multimeter. C. Restore power to the ECM. D. Run the "Air Inlet Heater Override" on Cat ET and observe the current reading on the multimeter. Note: Do not leave the "Air Inlet Heater Override" On. Avoid unnecessary cycling of the air
inlet heater in order to prevent the battery from discharging. The "Air Inlet Heater Override" has a one minute timer in order to disable the test when the time expires. E. Stop the "Air Inlet Heater Override". F. Remove power from the ECM. Expected Result:
The current reading is between 77 and 95 Amperes. Results: •
OK - The current is within the specified ranges. Repair: The current is within the specified ranges. The air inlet heater circuit appears to be
operating correctly at this time. If an intermittent problem is suspected, refer to Troubleshooting, "Electrical Connectors - Inspect". STOP •
Not OK - The current reading is not within the specified ranges. Repair: Check continuity of the wire between the air inlet heater and engine ground. Check
the connections at the air inlet heater and at engine ground for corrosion. If the wire between the air inlet heater and engine ground is OK, replace the air inlet heater.Verify that the problem is resolved. STOP
Engine Speed/Timing Sensor Circuit - Test SMCS - 1912-038 System Operation Description:
Use this procedure to troubleshoot any suspect problems with the following sensors: •
Primary engine speed/timing sensor
•
Secondary engine speed/timing sensor
This procedure covers the following diagnostic codes: •
190-02 Loss of Engine Speed Signal
•
190-11 Engine Speed Sensor mechanical failure
•
342-02 Loss of Secondary Engine Speed signal
•
342-11 Secondary Engine Speed Sensor mechanical failure
The engine uses two engine speed/timing sensors. The primary engine speed/timing sensor and the secondary engine speed/timing sensor are used to detect the reference for engine speed and for engine timing from a unique pattern in the timing reference ring. The timing reference ring is located on the back of the camshaft gear. To determine rpm, the Electronic Control Module (ECM) counts the time between pulses that is created by the sensor as the gear rotates. Under normal operation, the secondary engine speed/timing sensor is used to determine timing for starting purposes. The secondary engine speed/timing sensor is used to determine when the piston in the No. 1 cylinder is at the top of the compression stroke. When the timing has been established, the primary engine speed/timing sensor is then used to monitor engine speed. When the timing has been established, the ECM triggers each injector in the correct firing order at the correct time. The actual timing and duration of each injection is based on engine rpm and on load. If the engine is running and the signal from one sensor is lost, no change in engine performance will be noticed. If the engine is running and the signals from both sensors are lost, fuel injection will be terminated and the engine will be shut down by the ECM. The engine will start when only one sensor signal is present. The engine will not start if the signals from both sensors are lost. Both sensors are magnetic sensors. The two sensors are not interchangeable. If a replacement of the ECM is required, the ECM parameters and the timing ca libration can be transferred from the suspect ECM to the replacement ECM. This feature requires the Caterpillar Electronic Technician (ET) and this feature is only possible if the existing ECM can communicate with Cat ET. Use the "Copy Configuration - ECM Replacement" feature on Cat ET. Complete all of the following tasks when you install a speed/timing sensor: •
Ensure that an O-ring is installed on the sensor. If the O-ring is damaged or missing, replace the O-ring.
•
Lubricate the O-ring with oil.
•
Ensure that the sensor is fully seated into the engine before tightening the bracket bolt.
•
Ensure that the electrical connector is latched.
•
Ensure that the harness is properly secured, and ensure that each tie-wrap is placed in the correct location.
g01181798
Illustration 1 Schematic for the engine speed/timing sensors
Test Step 1. Check for Diagnostic Codes
A. Connect Cat ET to the service tool connector. Refer to Troubleshooting, "Electronic Service Tools". B. Restore electrical power to the engine ECM. C. Start the engine and run the engine until the engine is at the normal operating temperature. Note: If the engine will not start, monitor the engine rpm on Cat ET while the engine is being
cranked. Cat ET may need to be powered from another battery while the engine is being cranked. D. Wait at least 30 seconds for activation of the diagnostic codes. Look for these codes on Cat ET: o
190-02
o
190-11
o
342-02
o
342-11
Expected Result:
One or both of the diagnostic codes that are listed above are logged or active. Note: If the engine will not start and Cat ET displayed 0 rpm during cranking, select "No Engine
rpm". Results: •
No Engine rpm - Engine rpm is not indicated on Cat ET. Proceed to Test Step 2.
•
Active or logged code - There is an active diagnostic code or a logged diagnostic code for an
engine speed/timing sensor. Proceed to Test Step 4.
•
No codes - Neither code is active or logged. Repair: Refer to the appropriate symptoms in Troubleshooting, "Troubleshooting Without a
Diagnostic Code". STOP Test Step 2. Check the Installation of the Sensor Assembly
A. Remove electrical power from the engine ECM. B.
Illustration 2
g01180490
Left side view (1) Engine (2) Mounting flange (3) Bracket
B. Visually inspect the sensor assembly without removing the sensor assembly from the engine. Flanges (2) must be flush against engine (1) in order to ensure proper operation. Inspect bracket (3). Verify that the bracket securely holds the flanges of the sensors flush against the engine. Verify that the bracket is not bent. If the bracket is bent or if an obstruction is preventing the sensor assembly from being installed correctly, the engine will not start. Note: The bracket cannot be replaced separately.
C. Remove the sensor assembly from the engine.
Illustration 3
g01180501
Exploded view of the engine speed/timing sensors (4) O-ring seals
D. Ensure that one O-ring (4) is installed on each sensor. Check the O-rings for damage. Replace the O-rings, if necessary. Results: •
OK - The sensor assembly's components are OK. Repair: Perform the following procedure in order to properly install the sensor assembly:
1. Lubricate each O-ring with engine oil. 2. Fully seat the sensor assembly in the engine. Note: If the sensor assembly will not fully seat into the engine, replace the sensor
assembly. 3. Tighten the bracket bolt. 4. Connect the sensor's electrical connectors. Verify that the connectors are latched on both sides. 5. Ensure that the harness is properly secured, and that the tie-wraps are placed in the correct location. Proceed to Test Step 3. •
Not OK - At least one of the sensor assembly's components is not OK. Repair: Obtain a new sensor assembly. Perform the following procedure in order to properly
install the sensor assembly: 5.
Lubricate each O-ring with engine oil.
