TOP VIEW
Inlet Air Heater
Inlet Air Heater Lamp Connector P40
Intake Manifold Air Temperature Sensor
Boost Pressure Sensor
Unit Injector Cylinder #6
Coolant Temperature Sensor 1
2
3
4
5
6
High Pressure Pump
Injector Harness Grommet
Injection Actuation Pressure Control Valve (IAPCV)
Injection Actuation Pressure Sensor
Engine Oil Temperature Sensor
Electronic Control Module (ECM) Timing Calibration Probe Connector J24/P24
3126 Truck Engine Electrical System
1BW1-UP
SENR9628 November 2001
© 2001 Caterpillar All Rights Reserved
Injection Actuation Pressure Control Valve (IAPCV)
Engine Oil Temperature Sensor
Injection Actuation Pressure Sensor
Intake Manifold Air Temperature Sensor
Injector Harness Grommet
High Pressure Pump Ground Stud
Top Speed/Timing Sensor
Timing Calibration Probe Connector J24/P24 *
*
Bottom Speed/Timing Sensor
Printed in U.S.A.
ECM Ground Strap
LEFT SIDE VIEW
Electronic Control Module (ECM) ECM Vehicle Harness Connector J1/P1
ECM Engine Harness Connector J2/P2
A B
A701-GY A721-WH
A B
J29 P29
A702-PU A722-YL
A B
J30 P30 CYL NO.1
A703-BR A723-OR
J31 P31 CYL NO.2
A B
A704-GN A724-WH
A B
J32 P32 CYL NO.3
A705-BU A725-YL
A B
J33 P33 CYL NO.4
CYL NO.5
ENGINE SPEED / TIMING ENGINE SPEED / TIMING +
BOTTOM SPEED/TIMING SENSOR
ENGINE SPEED / TIMING ENGINE SPEED / TIMING +
A B
J9
E963-BK E964-WH
1 2
A D797-PK B D798-BK J36 P36
E963-BK E964-WH
P9 A B
J4
E965-BU E966-YL
E965-BU E966-YL A746-PK D841-GN 995-BU C967-BU E795-YL
P4
BOOST PRESSURE SENSOR
BOOST PRESSURE SENSOR COMMON +5V
GN YL OR
INJECTION ACTUATION PRESSURE SENSOR
INJ ACTUATION PRESS. SENSOR COMMON +5V
GN YL OR
C A746-PK B 993-BR A 997-OR P3 J3
993-BR 997-OR
D796-OR C B A
ENG SP/TMG #1ENG SP/TMG #1+
ENG SP/TMG #2ENG SP/TMG #2+ BOOST PRESSURE INJ ACTUATION PRESS. COOLANT TEMP INTAKE MANF AIR TEMP OIL TEMP
SENSOR COMMON +5V
INLET AIR HEATER
COOLANT TEMP SENSOR COMMON +5V
WH BK OR
C B A
995-BU 993-BR 997-OR
INLET AIR HEATER RELAY J37 P37 D812-RD 1 D796-OR 2
INTAKE MANF AIR TEMP SENSOR COMMON +5V
WH BK OR
C B A
C967-BU 993-BR 997-OR
N/O
D812-RD D796-OR
(+) BATTERY SUPPLY WIRES
INJECTOR 1 INJECTOR COMMON 1 INJECTOR 2 INJECTOR COMMON 2 INJECTOR 3 INJECTOR COMMON 3 INJECTOR 4 INJECTOR COMMON 4 INJECTOR 5 INJECTOR COMMON 5 INJECTOR 6 INJECTOR COMMON 6 VEHICLE SPEED OUT+ VEH SP IN+/TDC PROBE+ VEH SP IN-/TDC PROBEVEHICLE SPEED OUTINJ ACTUATION PRESS. CONT VALVE IAP CONT VALVE COMMON
P35 J35
J21 P21
ENGINE OIL TEMPERATURE SENSOR
6 5 12 11 18 17 22 21 28 27 34 33 40 39 4 10 19 13 1 8 9 37 29 25 15 3 23 24 14 2 32 7 16 26 30 36 38 20 35 31
D841-GN 993-BR 997-OR
J10 P10
INTAKE MANIFOLD AIR TEMPERATURE SENSOR
A701-GY A721-WH A702-PU A722-YL A703-BR A723-OR A704-GN A724-WH A705-BU A725-YL A706-GY A726-OR D784-BU D810-PU D811-YL D785-GN D797-PK D798-BK
J24 P24 TIMING CALIBRATION PROBE CONNECTOR
INJECTION ACTUATION PRESSURE CONTROL VALVE
CYL NO.6
TOP SPEED/TIMING SENSOR
COOLANT TEMPERATURE SENSOR
A706-GY A726-OR
J34 P34
ELECTRONIC CONTROL MODULE (ECM)
P2 J2
INJECTOR HARNESS GROMMET
ENGINE OIL TEMP SENSOR COMMON +5V
WH BK OR
C B A
E795-YL 993-BR 997-OR
INLET AIR HEATER
J51 P51
INPUT SIGNAL WIRES TO ECM OUTPUT SIGNAL WIRES FROM ECM
TO +BATTERY
SENSOR SUPPLY VOLTAGE SIGNAL PLUS
TO ENGINE CYL HEAD (NOT CYL HEAD GND STUD)
SIGNAL MINUS
INLET AIR HEATER GROUND STRAP
(-) BATTERY / SENSOR RETURN
469 468
TO POWER PACK INTERFACE
C B K L M N P R S T U V W X Y Z E A A F B C D D E F G H J
C B K L M N P R S T U V W X Y Z E A A F B C D D E F G H J
469 468
B A APC
ECM GND STRAP
P40 B D796-OR A D812-RD
TO ECM MOUNTING BOLT
469 468
LAV B A
CONNECTED TO LAV HARNESS OR APC HARNESS
LAV INTERFACE HARNESS 35 30 37 40 38 14 2 29 22 7 1 18 5 28 4 6
570 571 572 573 574 575 89 577 578 586 585 579 581 580 581 580
3 8 9 10 11 12 13 15 16 17 19 20 21 23 24 25 26 27 31 32 33 34 36 39
TO VEHICLE COMPONENTS
J2 P1
ENGINE BULKHEAD
P6
+8V MULTI-FUNCTION SENSOR COMMON THROTTLE POSITION EXHAUST BRAKE XMSN NEUTRAL SW SERVICE BRAKE SW #1 FAST IDLE ENABLE SW SENSOR COMMON CHECK ENGINE LAMP ATA DATA LINK+ (J1587) ATA DATA LINK- (J1587) VEHICLE SPEED IN+ -BATTERY +BATTERY -BATTERY +BATTERY
FROM (J1) ELECTRONIC CONTROL MODULE (ENGINE)
C B K L M N P R S T U V W X Y Z e A a f b c D d E F G H J
TO POWER PACK INTERFACE J1
C B K L M N P R S T U V W X Y Z e A a f b c D d E F G H J
469 468
APC INTERFACE HARNESS 35 30 37 40 38 14 2 29 22 7 1 18 5 28 4 6
570 571 572 573 574 575 576 577 578 142 151 579 581 580 581 580
+8V MULTI-FUNCTION SENSOR COMMON THROTTLE POSITION EXHAUST BRAKE XMSN NEUTRAL SW SERVICE BRAKE SW #1 FAST IDLE ENABLE SW SENSOR COMMON CHECK ENGINE LAMP ATA DATA LINK+ (J1587) ATA DATA LINK- (J1587) VEHICLE SPEED IN+ -BATTERY +BATTERY -BATTERY +BATTERY
3 8 9 10 11 12 13 15 16 17 19 20 21 23 24 25 26 27 31 32 33 34 36 39
TO VEHICLE COMPONENTS
J1 P1
POWER PACK BULKHEAD
P1
FROM (J1) ELECTRONIC CONTROL MODULE (ENGINE)
J1
35 30 37 40 38 14 2 29 22 7 1 18 5 28 4 6 3 8 9 CONNECTED TO 10 LAV HARNESS OR 11 APC HARNESS 12 13 15 16 17 19 20 21 23 24 25 26 27 31 32 33 34 36 39
+8V MULTI-FUNCTION SENSOR COMMON THROTTLE POSITION EXHAUST BRAKE XMSN NEUTRAL SW SERVICE BRAKE SW #1 FAST IDLE ENABLE SW SENSOR COMMON CHECK ENGINE LAMP ATA DATA LINK+ (J1587) ATA DATA LINK- (J1587) VEHICLE SPEED IN+ -BATTERY +BATTERY -BATTERY +BATTERY NOT NOT NOT NOT NOT NOT NOT NOT NOT NOT NOT NOT NOT NOT NOT NOT NOT NOT NOT NOT NOT NOT NOT NOT
USED USED USED USED USED USED USED USED USED USED USED USED USED USED USED USED USED USED USED USED USED USED USED USED
J1
ELECTRONIC CONTROL MODULE (ECM)
B A
Inlet Air Heater
Inlet Air Heater Relay
Inlet Air Heater Ground Strap
RIGHT SIDE VIEW
SENR9525 November 1999
Electronic Service Tool Will Not Communicate with the ECM
Engine Pressure Sensor Open or Short Circuit Test Connect Electronic Service Tool to Cab Data Link and check for ACTIVE 5 Volt Sensor Supply Code.
ACTIVE Supply Code
NO ACTIVE Supply Codes
Engine Temperature Sensor Open or Short Circuit Test Connect an Electronic Service Tool and check for an ACTIVE Engine Temperature Sensor OPEN or SHORT Circuit Code. If the code is not ACTIVE and the Engine is not running properly, refer to Troubleshooting Without A Diagnostic Code.
Refer to +5Volt Pressure Sensor Supply Voltage Circuit Test
Check Electrical Connectors and Wiring. Active SHORT Circuit Code Turn the ignition key ON, engine OFF. Disconnect the Sensor Connector with the ACTIVE Short Circuit Code in order to create an Open Circuit condition. Code Changes To OPEN Circuit
SHORT Circuit Code Remains
If a Short Circuit code was Active before the sensor was disconnected and an Open Circuit code became Active after the sensor was disconnected then thoroughly inspect the connector for signs of moisture. Inspect the seals and connect the sensor. If the code reappears, the sensor or pigtail harness is the problem. Temporarily connect a new sensor but do not install it into the engine. If the code is no longer Active with the new sensor connected, replace the old sensor.
Check Electrical Connectors and Wiring. NOT OK
Active SHORT Circuit Code
Refer to Inspecting Electrical Connectors
Active OPEN Circuit Code Measure Sensor Supply Voltage with multimeter. Reading should be within 4.5 to 5.5 VDC range. Supply OK
NOT OK Refer to +5Volt Engine Pressure Sensor Supply Voltage Circuit Test
Install a short circuit between terminal-B and terminal-C of the Sensor Connector and check for an ACTIVE Short Circuit code. OPEN Circuit Code Active with jumper
SHORT Circuit Code Active with jumper
OK Remove the sensor signal wire from ECM connector P2 and the sensor connector. Bypass the signal wiring by connecting a jumper wire directly from ECM connector P2 to the sensor connector signal terminal. If the Diagnostic Code disappears with the bypass wire installed, repair or replace the harness. Otherwise, restart the test procedure.
With the ignition key ON and engine OFF, Disconnect the Sensor Connector with the ACTIVE Short Circuit Code in order to create an Open Circuit condition. Code Changes To OPEN Circuit
NOT OK If the OPEN Circuit code is NOT Active with the harness disconnected, or the SHORT Circuit code is NOT Active with the jumper (short) installed, temporarily install a test ECM. If the test ECM resolves the problem, install the old and verify problem returns. If the test ECM works and the original ECM does not, replace the ECM.
SHORT Circuit Code Remains
If a Short Circuit code was Active before the sensor was disconnected and an Open Circuit code became Active after the sensor was disconnected then thoroughly inspect the connector for signs of moisture. Inspect the seals and connect the sensor. If the code reappears, the sensor is the problem. Temporarily connect a new sensor but do not install it into the engine. If the code is no longer Active with the new sensor connected, replace the old sensor.
If a SHORT Circuit Code appears, temporarily connect the suspect sensor. If an OPEN Circuit code returns, replace the sensor and verify the diagnostic code does not return.
Disconnect the ECM Connector J2/P2 and check for Active diagnostic codes. The OPEN Circuit code should be Active with the harness disconnected. Install a jumper (short) between the ECM Connector J2 signal terminal and terminal-3. A SHORT Circuit code should be Active with the jumper installed.
Repair Service Tool
OK
Try to start the Engine.
Connect Electronic Service Tool to the Cab data link, turn ignition key switch ON, engine OFF. Attempt to establish communications with the ECM.
Does not start
ECM does not communicate
Engine starts, but ECM does not communicate with the Service Tool
NOT OK
Repair Cables
Refer to Inspecting Electrical Connectors
Disconnect ECM Connector P1 from the ECM. Use the Service Tool Bypass Harness as indicated in the Ignition Key Switch Circuit Test.
With the ignition key On and engine OFF, Install a short circuit between terminal-1 and terminal-2 of the Sensor Connector and check for an ACTIVE Short Circuit code. SHORT Circuit Code Active with jumper
If a SHORT Circuit Code appears, temporarily connect the suspect sensor. If an OPEN Circuit code returns, replace the sensor and verify the diagnostic code does not return.
Connect the Service Tool using a completely different set of Service Tool cables. No Communications
Active OPEN Circuit Code
OPEN Circuit Code Active with jumper
OK
ECM and Service Tool Communicate
3126B Truck Engine Electrical System 6PZ1-UP 7JZ1-UP
No Communications
Either the vehicle wiring or another device on the vehicle is causing the communication problem.
OK Remove the sensor signal wire from ECM connector P2 and the sensor connector. Bypass the signal wiring by connecting a wire directly from ECM connector P2 to the sensor connector signal terminal. If the Diagnostic Code disappears with the bypass wire installed, repair or replace the harness. Otherwise, restart the test procedure.
OK
NOT OK
Refer to the Ignition Keyswitch Circuit Test
Check ECM power, ground, and keyswitch connections with the ignition key switch ON. Battery voltage at ECM Connector J1/P1 terminal-52, 53 and 70, to terminal-65 and 67 should be 11.0 -13.5 VDC for a 12 Volt system and 22.0 - 27.0 for a 24 Volt system. OK
NOT OK Refer to the ECM Memory Test
A new ECM has an unprogrammed Personality Module. The engine will not start or communicate until the Personality Module in the ECM is Flash Programmed. Not a New ECM
Check the Ignition Key Switch status on the Service Tool. With the Ignition Key Switch ON, the status should display ON. If the status displays OFF, check for voltage from the battery. Battery voltage at ECM Connector J1/P1 terminal-70 to terminal-65 and 67 should be 11.0 -13.5 VDC for a 12 Volt system and 22.0 - 27.0 for a 24 Volt system.
Connect a test ECM. Turn the Ignition Key ON, engine OFF. If the new ECM communicates and the old ECM does not, reconnect the old ECM and verify the problem returns. If the new ECM communicates and the old ECM does not, replace the ECM. If the new ECM does not communicate, there is a problem with the cables or the battery.
NOT OK
OK NOT Refer OK to the ECM Memory Test NOT OK
Disconnect the ECM Connector J2/P2 and check for Active diagnostic codes. The OPEN Circuit code should be Active with the harness disconnected. Install a jumper (short) between the ECM Connector J2 signal terminal and terminal-18. A SHORT Circuit code should be Active with the jumper installed.
ECM Communicates
Ensure after-market engine protection devices (not installed by Caterpillar) are not active, preventing the ECM or Ignition Key Switch from receiving battery power.
Connect another Service Tool to the ECM, but use the same Service Tool Cables as in the previous step. No Communications
ACTIVE Open or Short Circuit Code
Check for ACTIVE Engine Pressure Sensor OPEN or SHORT Circuit Code. If the code is not ACTIVE and the Engine is not running properly, refer to Troubleshooting Without A Diagnostic Code. ACTIVE Open or Short Circuit Code
Does not crank, refer to engine will not crank.
Engine Cranks, But Will Not Start
Refer to the Engine Speed/Timing Circuit Test
If the Personality Module has been recently replaced/updated , connect and check for an active 252-11 Incorrect Engine Software.
Refer to the Ignition Keyswitch Circuit Test
OK
Observe engine rpm from Electronic Service Tool while cranking the engine. An rpm value should be displayed on the Service Tool. OK
If the Truck is equipped with a CAT ID , ensure Theft Deterrent is not Active . Turn the Ignition Key Switch ON, engine OFF, the CAT ID will indicate Theft Deterrent Active.
NOT OK If the OPEN Circuit code is NOT Active with the harness disconnected, or the SHORT Circuit code is NOT Active with the jumper (short) installed, temporarily install a test ECM. If the test ECM resolves the problem, install the old and verify problem returns. If the test ECM works and the original ECM does not, replace the ECM.
OK
Monitor the exhaust stack while cranking - if no smoke is present there may be a fuel supply or quality problem. Check fuel pressure, priming, and filters. OK
Check for combustion problems, mechanical problems or extreme temperatures.
NOTE: Refer to the Electronic Troubleshooting Guide for detailed information.
NOTE: Refer to the Electronic Troubleshooting Guide for detailed information.
NOTE: Refer to the Electronic Troubleshooting Guide for detailed information.
© 1999 Caterpillar All Rights Reserved
Printed in U.S.A.
SENR9525-00 8 Page, JVD
NOTE: Refer to the Electronic Troubleshooting Guide for detailed information.
3126B ENGINE HARNESS WIRING DIAGRAM
INTAKE MANIFOLD GROMMET
L983-WH
12 11 10 9 8 7
L983-WH L984-OR L984-OR L985-YL L985-YL J301 P301 B A
J302 P302 B A
INJECTOR CYLINDER NO.1
J303 P303 B A
J304 P304 B A
J305 P305 B A
J306 P306 B A
INJECTOR CYLINDER NO.3
INJECTOR CYLINDER NO.4
INJECTOR CYLINDER NO.5
INJECTOR CYLINDER NO.6
INJECTOR CYLINDER NO.2
A706-GY
ENGINE HARNESS CONNECTOR P2 J2 L983-WH L984-OR L985-YL A706-GY A705-BU A704-GN A703-BR A702-PU A701-GY
6 5 4 3 2 1
44 45 46 55 54 39 38 37 36 47 67 68 1 63 64 4 5 61 62 70 40 27 6 7 14 3 2 15 16 17 24 42 41 25 50 52 53 60 9 32 35 33 34 26 18 10 11 12
P300 J300
A705-BU A704-GN A703-BR A702-PU A701-GY A B
INJECTION ACTUATION PRESSURE CONTROL VALVE
G854-PK G855-PU
J500 P500 GN YL OR
ENGINE BOOST PRESSURE ENGINE PRESSURE SENSOR COMMON ENGINE PRESSURE SENSOR +5V
ENGINE BOOST PRESSURE SENSOR
A746-PK G829-GN G828-WH
C B A
A746-PK G849-BR
J200 P200
GN YL 0R
ENGINE INJECTION ACTUATION PRESSURE SENSOR
ENGINE INJECTION ACTUATION PRESS ENGINE PRESSURE SENSOR COMMON ENGINE PRESSURE SENSOR +5V
ENGINE ATMOSPHERIC PRESSURE SENSOR NOTE A
ENGINE ATMOSPHERIC PRESSURE ENGINE PRESSURE SENSOR COMMON ENGINE PRESSURE SENSOR +5V
C B A
A747-GY G829-GN G828-WH
G849-BR G829-GN G828-WH 994-GY G827-BU G826-BR
P204 J204
GN YL OR
A747-GY G829-GN G828-WH
C B A
P203 J203
ENGINE OIL PRESSURE SENSOR NOTE A
GN YL OR
ENGINE OIL PRESSURE SENSOR ENGINE OIL PRESSURE SENSOR COMMON ENGINE OIL PRESSURE SENSOR +5V
995-BU C967-BU
994-GY G827-BU G826-BR
C B A
G846-YL
P201 J201
G833-PK TOP CAMSHAFT ENGINE SPEED/TIMING SENSOR
ENGINE COOLANT TEMPERATURE ENGINE TEMPERATURE SENSOR COMMON
ENGINE COOLANT TEMPERATURE SENSOR
A B
TOP CAMSHAFT SPEED/TIMINGTOP CAMSHAFT SPEED/TIMING+
995-BU G833-PK
1 2
J100 P100
ENGINE INTAKE MANIFOLD AIR TEMPERATURE SENSOR
ENGINE INTAKE MANIFOLD AIR TEMPERATURE ENGINE TEMPERATURE SENSOR COMMON
ENGINE OIL TEMPERATURE SENSOR
ENGINE OIL TEMPERATURE ENGINE TEMPERATURE SENSOR COMMON
49 48 13 19 20 21 28 29 30 59 58 31 43 51 22 23 56 57 65 66 69 8
BOTTOM CAMSHAFT ENGINE SPEED/TIMING SENSOR
C967-BU G833-PK
1 2
E963-BK E964-WH
J401 P401
J103 P103
E965-BU E966-YL
A B
BOTTOM CAMSHAFT SPEED/TIMINGBOTTOM CAMSHAFT SPEED/TIMING+
J402 P402 G846-YL G833-PK
1 2
ENGINE TIMING CALIBRATION PROBE+ ENGINE TIMING CALIBRATION PROBE-
J101 P101
G856-WH G857-YL
A B
(+) BATTERY SUPPLY WIRES
J400 P400 TO INTAKE AIR HEATER CIRCUIT FUSIBLE PROTECTION
INPUT SIGNAL WIRES TO ECM
K995-OR J501 P501 C987-RD 1 G850-BU 2
OUTPUT SIGNAL WIRES FROM ECM SENSOR SUPPLY VOLTAGE SIGNAL PLUS
(-) BATTERY / SENSOR RETURN
IAP CONTROL VALVE IAP CONTROL VALVE COMMON ENGINE BOOST PRESSURE ENGINE INJECTION ACTUATION PRESSURE
ENGINE ATMOSPHERIC PRESSURE ENGINE PRESSURE SENSOR COMMON ENGINE PRESSURE SENSOR +5V
ENGINE OIL PRESSURE SENSOR ENGINE OIL PRESSURE SENSOR COMMON ENGINE OIL PRESSURE SENSOR +5V ECM GROUND STRAP
TO ECM ENGINE COOLANT TEMPERATURE MOUNTING ENGINE INTAKE MANIFOLD AIR TEMPERATURE BOLT ENGINE OIL TEMPERATURE ENGINE TEMPERATURE SENSOR COMMON
TOP CAMSHAFT SPEED/TIMINGTOP CAMSHAFT SPEED/TIMING+
BOTTOM CAMSHAFT SPEED/TIMINGBOTTOM CAMSHAFT SPEED/TIMING+
ENGINE TIMING CALIBRATION PROBE+ ENGINE TIMING CALIBRATION PROBE-
INTAKE AIR HEATER RELAY
N/O RELAY
TO ENGINE CYLINDER HEAD (NOT CYLINDER HEAD GROUND STUD)
COMPONENTS ARE SHOWN WITH THE KEY OFF UNLESS OTHERWISE SPECIFIED: ALL WIRES TO BE 18 AWG OR LARGER SAE J1560 TYPE TXL OR EQUIVALENT. FOR TWISTED PAIR SPECIFICATION SEE SAE J1708
SIGNAL MINUS
G850-BU
INJECTOR COMMON CYLINDERS 1 & 2 INJECTOR COMMON CYLINDERS 3 & 4 INJECTOR COMMON CYLINDERS 5 & 6 INJECTOR CYLINDER 6 INJECTOR CYLINDER 5 INJECTOR CYLINDER 4 INJECTOR CYLINDER 3 INJECTOR CYLINDER 2 INJECTOR CYLINDER 1
P1 J1
INTAKE AIR HEATER
P648 G850-BU C987-RD
B A
TO CONNECTOR J648
VEHICLE HARNESS CONNECTOR NOTE A: A DASHED LINE SPECIFIES AN OPTIONAL FEATURE, NOT AVAILABLE ON ALL SYSTEMS.
3126B VEHICLE HARNESS WIRING DIAGRAM
INTAKE AIR HEATER LAMP
TO INTAKE AIR HEATER RELAY
100A WITH 130A PEAK AT 11V
TO CONNECTOR P648
B A
(CONTACT SIDE) C987-RD
J648 ENGINE HARNESS CONNECTOR
CIRCUITS WITHIN THIS AREA ARE RECOMMENDATIONS CHECK ENGINE LAMP C987-RD
K995-OR
N/O RELAY
L994-YL P2 J2
WARNING LAMP
OFF ON START
659-PK L994-YL K998-BU G880-PK
659-PK
FAST IDLE ENABLED LAMP
NOTE A
G880-PK
EXHAUST BRAKE ON/OFF SWITCH
EXHAUST BRAKE SOLENOID
KEY SWITCH
FLYBACK DIODE
E718-PK E991-GY G836-WH
NOTE A
SPEEDOMETER NOTE A
SIGNAL+
C974-PU
SIGNAL-
C973-GN
STARTER MOTOR (12V)
ALTERNATOR GROUND
C E D F J1587 DATA LINK NEGATIVE B E793-BU J1587 DATA LINK POSITIVE A E794-YL TO J1939 DATA LINK CONNECTOR TO J1939 DATA LINK CONNECTOR TO J1939 DATA LINK CONNECTOR +BAT. -BAT.
- 12V +
BATTERY 3
- 12V +
- 12V +
BATTERY 2
C974-PU C973-GN NOTE A
CAB DIAGNOSTIC CONNECTOR
BATTERY 1
NOTE A
TACHOMETER NOTE A
SIGNAL+
450-YL
SIGNAL-
451-BR
993-BR F713-OR 450-YL 451-BR NOTE A E793-BU E794-YL A249-BK K990-GN K900-YL
NOTE A
TO ALLISON AT/MT SHIFT MODULATOR FOR MECHANICAL TRANSMISSION
J906-BR 14 AWG GXL 14 AWG GXL 14 AWG GXL 14 AWG GXL
20A ENGINE BLOCK
101-RD 101-RD 229-BK 229-BK G838-BR G839-BU
NOTE A C978-BR C979-OR
H795-PK
SET/RESUME
H795-PK
C978-BR C979-OR K999-GN K980-PK L902-GN G840-PU C975-WH K982-YL G841-GN C992-PU
FAST IDLE ENABLE SWITCH
NOTE A
H795-PK
N/O MOMENTARY SWITCH
L902-GN
C975-WH
CRUISE CONT ON/OFF
SERVICE BRAKE PEDAL POSITION N/C H795-PK (PEDAL RELEASED POSITION)
C992-PU SERVICE BRAKE PEDAL POSITION #2 N/O +BAT. G882-WH
CLUTCH PEDAL POSITION N/C H795-PK (PEDAL RELEASED POSITION)
G842-GY G882-WH G843-OR L901-GY C977-BU
(PEDAL RELEASED POSITION) NOTE A
NOTE A
C977-BU
DIAGNOSTIC ENABLE SWITCH NOTE A
SENR9525-00
8 Page, Color 2, JVD
29 28 30 31 48 61 10 12 13 15 16 63 36 37 27 26 3 17 38 39 57 43 9 8 42 34 50 1 14 70 25 52 53 65 67 19 20 51 35 44 56 58 40 21 59 60 7 45 55 47 64 6 18 22 23 2 46 49 54 62 24 41 69 32 33 68 5 4 66 11
H795-PK
N/O MOMENTARY SWITCH
A/C HIGH PRESS. SWITCH N/C NOTE A
G879-OR G844-PK C983-WH C984-YL 409-OR
G844-PK +BAT.
TRANSMISSION NEUTRAL N/O (TRANSMISSION IN GEAR) NOTE A
409-OR
E971-GN
H795-PK
E971-GN PASSIVE MAGNETIC VEHICLE SPEED SENSOR
COMPONENTS WITHIN THIS AREA ARE CATERPILLAR PROVIDED ACCELERATOR PEDAL SENSOR/SWITCH SENSOR COMMON +8 V ACCELERATOR PEDAL POSITION
B A C
BK RD WH
1 2
G808-BU G809-GN G845-PU H795-PK C985-BU C986-BR G837-YL
H795-PK C985-BU C986-BR
J403 P403
SENSOR ACCELERATOR PEDAL POSITION
G808-BU G809-GN
COOLING FAN SOLENOID NOTE A
FLYBACK DIODE
WARNING LAMP CHECK ENGINE LAMP OUTPUT #1 OUTPUT #9
OUTPUT #2 OUTPUT #3 OUTPUT #4
SPEEDOMETER POSITIVE SPEEDOMETER NEGATIVE
INPUT SENSOR COMMON #2 INPUT #14 TACHOMETER POSITIVE TACHOMETER NEGATIVE
J1587 DATA LINK NEGATIVE J1587 DATA LINK POSITIVE J1939 DATA LINK SHIELD J1939 DATA LINK NEGATIVE J1939 DATA LINK POSITIVE
IGNITION KEY SWITCH UNSWITCHED +BATTERY UNSWITCHED +BATTERY -BATTERY -BATTERY OUTPUT #6 OUTPUT #7 SET RESUME INPUT #1 INPUT #2 INPUT #18 OUTPUT #8 CRUISE CONTROL ON/OFF SWITCH INPUT #3 INPUT #4 SERVICE BRAKE PEDAL POSITION SWITCH INPUT #5 INPUT #13 INPUT #6 INPUT SENSOR COMMON #1 CLUTCH PEDAL POSITION SWITCH +5V INPUT #7 ENGINE COOLANT LEVEL NORMAL ENGINE COOLANT LEVEL LOW INPUT #12 INPUT #11 VEHICLE SPEED IN POSITIVE VEHICLE SPEED IN NEGATIVE INPUT #8 AP SENSOR/SWITCH SENSOR COMMON +8V ACCELERATOR PEDAL POSITION OUTPUT #5
P1 J1 VEHICLE HARNESS CONNECTOR
NOTE A: A DASHED LINE SPECIFIES AN OPTIONAL FEATURE, NOT AVAIL ABLE ON ALL SYSTEMS.
ECM AMP Connectors
13
1
23
14
31
24
39 47
32 40
57 70
48 58
1
2
3
4
5
6
8
>PEI<
14
31 36
ECM Side
40
47
48
57
1
1
23
14
14
31
24
24
39 47
32 40
57 70
48 58
2
3
4
5
6
8
9 10 11 12 13
>PEI<
23 31 36
40
47
48
57
58 59 60 61 62 63
65 66 67 68 69 70
Harness Side
Engine Harness Connector P2
Deutsch DT Connector Receptacle
Deutsch DT Connector Plug
A
Pressure Sensor Connectors
A
B
C
C
2
65 66 67 68 69 70
Harness Side
Vehicle Harness Connector P1
13
B
23
24
58 59 60 61 62 63
ECM Side
9 10 11 12 13
1
Temperature Sensor Connectors
1
2
123456 654321 Injector Harness Connectors 7 8 9 10 11 12
12 11 10 9 8 7
PID-FMI 1-11 2-11 3-11 4-11 5-11 6-11 22-13 30-08 30-13 41-03 41-04 42-11
Description
Diagnostic Code Listing Flash PID-FMI Codes 72 102-07 72 105-03 73 105-04 73 108-03 74 108-04 74 110-00 42 110-03 29 110-04 29 110-11 21 111-01 21 111-02 18 111-11
70-05 70-06 71-00 71-01 71-14 84-00 84-01
Cylinder 1 Fault Cylinder 2 Fault Cylinder 3 Fault Cylinder 4 Fault Cylinder 5 Fault Cylinder 6 Fault Check Timing Sensor Calibration Invalid PTO Throttle Signal PTO Throttle Sensor Calibration 8 Volt Supply Above Normal 8 Volt Supply Below Normal Injection Actuation Press Control Valve Driver Fault Ignition Key Switch Fault Loss of Engine RPM Signal on Engine Speed and Timing Sensor Number 2 No Pattern on Engine Speed and Timing Sensor Number 2 Inlet Air Heater Open Circuit Inlet Air Heater Short Circuit Idle Shutdown Override Idle Shutdown Occurrence PTO Shutdown Occurrence Vehicle Overspeed Warning Loss of Vehicle Speed Signal
84-02
Invalid Vehicle Speed Signal
36
190-11
84-08 84-10 91-08 91-13 100-03 100-04 100-11 102-03 102-04
Vehicle Speed Out of Range Vehicle Speed Rate of Change Invalid Throttle Signal Throttle Sensor Calibration Oil Press Sensor Open Circuit Oil Press Sensor Short Circuit Very Low Oil Press Boost Press Sensor Open Circuit Boost Press Sensor Short Circuit
36 36 32 28 24 24 46 25 25
224-11 224-14 231-11 232-03 232-04 246-11 247-11 252-11 253-02
43-02 64-02 64-11
Description Excessive Boost Pressure Inlet Manifold Air Temp Sensor Open Circuit Inlet Manifold Air Temp Sensor Short Circuit Atmospheric Press Sensor Open Circuit Atmospheric Press Sensor Short Circuit High Coolant Temp Warning Coolant Temp Sensor Open Circuit Coolant Temp Sensor Short Circuit Very High Coolant Temp Low Coolant Level Warning Coolant Level Sensor Fault Very Low Coolant Level
Flash Codes 25 38 38 26 26 61 27 27 61 62 12 62
71 34
164-00 164-02
Injection Actuation Press Out of Range Injection Actuation Press Sensor Erratic
17 15
34
164-03
Injection Actuation Press Open Circuit
15
49 49 01 47 47 41 31
164-04 164-11 168-02 175-03 175-04 190-00 190-02
Injection Actuation Press Short Circuit Injection Actuation Press System Intermittent Battery Power to the ECM Oil Temp Sensor Open Circuit Oil Temp Sensor Short Circuit Engine Overspeed Warning Loss of RPM Signal on Engine Speed and Timing Sensor Number 1 No Pattern on Engine Speed and Timing Sensor Number 1 Theft Deterrent Enabled Engine Cranking / Theft Deterrent Enabled J1939 Data Link Fault 5 Volt Supply Above Normal 5 Volt Supply Below Normal Service Brake Switch Number 1 Fault Service Brake Switch Number 2 Fault Incorrect Engine Software Check Customer or System Parameters
15 39 51 24 24 35 34 34 00 00 58 21 21 00 00 59 59
