Power Train Electronic Control System 966

Product: WHEEL LOADER Model: 966H WHEEL LOADER TAL02276 Configuration: 966H Wheel Loader TAL00001-UP (MACHINE) POWERED BY C11 Engine

Systems Operation 966H Wheel Loader and 972H Wheel Loader Power Train Media Number -RENR8845-02

Publication Publica tion Date -01/12/2011

Date Updated -06/12/2011

i02410641

Power Train Electronic Control System SMCS - 4800; 7610-DTN

The main functions of the power train electronic control system follow: "Neutral Start Function", "Manual Shift Function", "Automatic Shift Function", "Transmission Neutralizer Function", "Parking Brake Function", "Backup Alarm Function", "Secondary Steering (If Equipped)", "Ride Control Function (If Equipped)", "Speed Limiter (If Equipped)" and "Diagnostic Operation".

Neutral Start Function

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g00329538 Illustration 1 Start Relay

The start relay is an output of the power train electronic control module (ECM). The start relay turns the start solenoid on and off. The start solenoid controls the starting motor. When the operator turns the key start switch to the START position and the power train ECM decides that all the starting conditions are satisfied, the power train ECM energizes the start relay with a +battery signal. The power train ECM will not allow the engine to be started unless the transmission direction and speed control lever (if equipped) is in the NEUTRAL position. The power train ECM will not allow the engine to be started unless the transmission transmission direction control switch (if equipped) is in the NEUTRAL position. If the transmission direction and speed control lever (if equipped) or the transmission direction control switch (if equipped) is in the NEUTRAL position, the power train ECM activates the start relay. The start start relay allows the starting motor to turn. The power train ECM will not allow the starter to activate if the engine is runn ing. Also, high battery voltage and the machine security system (if equipped) can prevent activation of the starter. The start relay has a connector with two contacts. One contact receives power po wer from connector contact J1-1 of the power train ECM. The other contact returns power to connector con nector contact J2-1 of the power train ECM. Terminal 3 of the start relay connects to a +battery source. Terminal 4 connects to the start











Reference: For more information on the power train electronic control module (ECM), refer to the Service Manual module Systems S ystems Operation, "Electronic Control Module (Power Train)" for the machine that is being serviced.

Manual Shift Function Table 1 Modulating Valve (Transmission Clutch)

Fourth Speed Forward

3 and 2

Third Speed Forward

4 and 2

Second Speed Forward

5 and 2

First Speed Forward

6 and 2

Neutral

3

First Speed Reverse

6 and 1

Second Speed Reverse

5 and 1

Third Speed Reverse

4 and 1

Fourth Speed Reverse

3 and 1

Conventional Steering











g00823325 Illustration 2 (1) Autoshift switch (2) Manual position











g01179950 Illustration 3 (3) Transmission downshift switch (A) Transmission direction control switch











g00823383 Illustration 4 (4) Transmission direction and speed control lever

In order to manually shift the transmission, the autoshift switch (1) must be in the MANUAL position (2). Shifting the transmission transmission is the main function of the power train electronic control module (ECM). The power train ECM interprets the changes in the switch position. After the power train ECM interprets the changes in the switch position, the power train train ECM shifts the transmission. The operator can set the transmission t ransmission direction with transmission direction control switch (A) or transmission direction and speed control lever (4). Transmission direction control switch (A) is a sealed unit. The transmission direction control switch is located next to the bucket controls. In order to use transmission direction control switch (A), place the lever (4) in the NEUTRAL position. Select the direction that is desired by using the transmission transmission direction control switch













Transmission direction and speed control lever (4) is a sealed unit. The transmission direction and speed control lever is mounted on the steering column. The transmission direction and speed control lever allows the operator to select a speed range by rotating the control lever. The operator can select a direction by moving movin g the transmission direction and speed control lever forward or backward. The transmission will remain in the selected direction u ntil the transmission direction and speed control lever is moved forward or ba ckward. The transmission will remain in the selected speed until the transmission direction and speed control lever is rotated to a different speed. When transmission downshift switch (3) is depressed, d epressed, the transmission downshift switch signals the power train ECM to downshift the transmission by one speed. If second speed forward or second speed reverse are selected, the transmission will shift to first speed by dep ressing transmission downshift switch (3). The transmission will remain in first speed until transmission direction and speed control lever (4) is shifted into the opposite direction or to the NEUTRAL position. When the key start switch is turned from the O FF position to ON position, the power train ECM is activated. When the power train ECM is first activated all of the clutch solenoid modulating valves are de-energized. The clutch solenoid modulating valves are de-energized regardless of the position of transmission direction and speed control lever (4) or transmission direction control switch (A). The power train ECM then d etermines if the transmission direction and speed control lever is in the NEUTRAL position. The po wer train ECM disables the transmission if the NEUTRAL position is NOT selected. If the NEUTRAL position is NOT NOT selected, the transmission direction and speed control lever must be returned to th e NEUTRAL position before a direction can be selected. The power train ECM activates the start relay and the power train ECM allows the engine to start if the transmission direction and speed control lever is in the NEUTRAL position. The power train ECM allows the initial selected selected speed to be changed if the transmission direction and speed control lever is in the NEUTRAL position. Note: Transmission direction and speed control lever (4) and transmission direction control switch (A) must be in the NEUTRAL position when the key start switch is turned to the START position. If the transmission direction direction and speed control lever is not in the NEUTRAL position, the start relay will not be activated when the key start switch is turned. For additional a dditional











Command Control Steering Table 2 Normal Shifting Sequence Speed Range and Direction

REVERSE Position Transmissio n Shift

NEUTRAL Position Transmissio n Shift

FORWARD Position Transmissio n Shift

UP SHIFT Position Transmissio n Shift

DOWN SHIFT Position Transmissio n Shift

4F

4R

Neutral (1) (4N)

3F

3R

Neutral (1) (3N)

No Change

4F

2F

2F

2R

Neutral (1) (2N)

No Change

3F

1F

1F

1R

Neutral (1) (1N)

No Change

2F

No Change

Last (2)

Next (3)

Prior (3)

Neutral (1) (1N, 2N, 3N, 4N)

Last (2)

No Change

No Change

No Change

3F

1R

No Change

Neutral (1) (1N)

1F

2R

No Change

2R

No Change

Neutral (1) (2N)

2F

3R

1R

Neutral











g00823503 Illustration 5 (5) Autoshift switch (6) Manual position











g00823455 Illustration 6 (7) Transmission direction control switch (8) Transmission speed switch

The autoshift switch (5) tells the power train ECM of the d esired shift mode, AUTO mode or MANUAL mode. In order to manually shift the transmission, the autoshift switch must be in the MANUAL (6) position. Shifting the transmission is the main function of the power train electronic control module (ECM). The power train ECM interprets the changes in the switch position. After the power train ECM interprets interprets the changes in the switch position, the power train ECM shifts the transmission. The transmission direction control switch (7) and the transmission speed switch (8) are located











co nnections is required. This will allow the power train Note: The correct status of the four input connections ECM to decide when the power train ECM should make each shift. When the key start switch is turned from the OFF position to ON position, the power train EC M is activated. When the power train ECM is first activated all of the clutch solenoid modulating valves are de-energized. The clutch solenoid modulating valves are de-energized regardless of the position of transmission direction control switch (5). The power train ECM then determines if transmission direction control switch (7) is in the NEUTRAL position. The power train ECM disables the transmission if the NEUTRAL position is NOT selected. If the transmission direction control switch is in the NEUTRAL position, the p ower train ECM selects the current speed and the current direction as neutral. The power train ECM activates the start relay if the transmission direction control switch is in the NEUTRAL position. When the start relay is activated, the engine is allowed to start. Note: Transmission direction control switch (7) must be in the NEUTRAL position when the key is turned to the START position. If the transmission direction control switch is not in the NEUTRAL position, the start relay will not be activated. For additional information on the neutral start function, refer to "Neutral Start Function". Reference: For more information on the Caterpillar Monitoring System, refer to the Service Manual module Systems Operation, "Monitoring System (Power Train Functions)" for the machine that is being serviced. Reference: For additional information on the transmission direction control switch and the transmission speed switch, refer to the Service Manual module S ystems Operation, "Switches" for the machine that is being serviced. Reference: For more information on the key ke y start switch, refer to the Service Manual module Systems Operation, "Switches" for the machine that is b eing serviced. Reference: For more information on the power train electronic control module (ECM), refer to the Service Manual module Systems S ystems Operation, "Electronic Control Module (Power Train)" for the machine that is being serviced.























g01179964 Illustration 8 (4) Downshift switch.











Command Control Steering











g00823646 Illustration 10 (10) . (11) . (10) Transmission direction control switch











Note: If a downshift would cause an engine overspeed condition, the power train ECM will prevent the downshift from occurring.

Transmission Neutralizer Function























Note: When the transmission is neutralized, the readout on the Caterpillar Monitoring System continues to show the speed that is selected but the direction will read neutral. Note: When the transmission neutralizer is disabled, the neutralizer disable indicator on the dash is activated. Reference: For more information on the left pedal position sensor, refer to the Service Manual module Systems Operation, "Switches" for the machine that is bein g serviced. Reference: For more information on the transmission neutralizer override switch, refer to the Service Manual module Systems Operation, "Switches" for the machine that is being serviced. Reference: For more information on the power train electronic control module (ECM), refer to the Service Manual module Systems S ystems Operation, "Electronic Control Module (Power Train)" for











Caterpillar Monitoring System initiates a Warning Category 3. A Warning Category 3 causes the parking brake indicator and the action lamp to flash. The action alarm will also sound. Reference: For more information on the Caterpillar Monitoring System, refer to the Service Manual module Systems Operation, "Monitoring Systems (Power Train Functions)" for the machine that is being serviced. Reference: For more information on the parking brake pressure switch, refer to the Service Manual module Systems Operation, "Switches" for the machine that is being serviced. Reference: For more information on the power train electronic control module (ECM), refer to the Service Manual module Systems S ystems Operation, "Electronic Control Module (Power Train)" for the machine that is being serviced.











The optional secondary steering system provides steering control of the machine when the primary steering system has failed. The secondary steering system system is intended for emergency use only. Reference: For more information on the secondary steering s ystem, refer to the Service Manual module Systems Operation, "Secondary Steering S ystem" for the machine that is being serviced.

Ride Control Function (If Equipped)























train ECM. The number three ride control solenoid receives power from the connector contact J2-3 of the power train ECM. All of the ride control solenoids return power to connector contact J2-4 of the power train ECM. Reference: For more information on the Caterpillar Monitoring System, refer to the Service











service codes of the faults that are not related to the power train system. MID 081 identifies the power train ECM as the source of the service code. Component Identifier (CID) - The components that are faulty are noted by the CID. The following components are examples: start relay and reverse solenoid. The CID is a four digit











tha t is needed to set a fault can last Note: The time that is needed to clear a fault and the time that less than 1 second up to 60 seconds. Da ta Link, refer to the Service Manual module Reference: For more information on the CAT Data Systems Operation, "CAT Data Link" for the mach ine that is being serviced.

Power Train Electronic Control System 966

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