IT28G Integrated Toolcarrier and 924G, 924GZ and 928G Wheel Loaders Transmission Control (Shift Lever) Caterpillar

System Operation Description:

• Place the implement handle remote FNR switch and the steering column shift lever both in neutral.

• Start the engine.

• Place the auto-shift mode switch in the MANUAL position.

Note: The highest gear available in REVERSE is third gear.

• Disengage the parking brake and operate the machine in all speeds and in both directions using the steering column shift lever. The implement handle remote FNR switch should remain in the Neutral position.

• Observe that the transmission operates in all gears and observe that the transmission operates in both directions.

• Place the steering column shift lever in NEUTRAL.

• Operate the machine in all speeds, and in both directions, using the implement handle remote FNR switch

• Observe that the transmission operates in all gears and observe that the transmission operates in both directions.

If the transmission does not operate properly and a problem in the shift lever is still suspected, perform the following test .

Illustration 1	g00987048

Test Step 1. CHECK THE SHIFT LEVER SIGNAL ON THE ET STATUS SCREEN.

1. Disconnect the FNR switch harness 4 pin connector "C-C50" that is on the shift lever. Connect a jumper wire from pin 3 to pin 4 on the shifter 4 pin connector.

2. Connect the Electronic Technician (ET) to the machine.

3. Turn the disconnect switch and the key start switch to the ON position.

4. Select the power train ECM and go to status screen 4.

5. Move the shift lever through all of the possible positions. Observe the status of the "Shift Lever Position" on the ET screen.

Expected Result:

The status of the shift lever position changes properly.

Results:

• STATUS CHANGES PROPERLY - The status of the shift lever position changes properly. The diagnostic code does not exist at this time. Proceed to Test Step 5.

• STATUS ALWAYS INVALID - The status on the ET screen is "DATA FAULT" in all positions of the shifter. Proceed to Test Step 2.

• STATUS INVALID IN A POSITION - The status on the ET screen is "DATA FAULT" in a particular position. Proceed to Test Step 3.

Test Step 2. CHECK FOR POWER AND GROUND AT THE SHIFTER.

1. At the shifter, connect the positive (red) multimeter lead to wire 110-GN(Green). Connect the negative (black) multimeter lead to wire 200-BK(Black).

2. Measure the voltage between the two wires.

Expected Result:

The voltage is system voltage.

Results:

• OK - The voltage is system voltage. Proceed to Test Step 3.

• NOT OK - The voltage is not system voltage. The wiring to the shifter may have failed.

  Repair: First check the fuse for wire 110-GN(Green). If the fuse is bad, replace the fuse. If the fuse is good, the wiring harness may have failed. Repair the wiring harness or replace the wiring harness between the fuse and the shifter or between the shifter and ground.

  STOP

Test Step 3. CHECK THE SHIFTER HARNESS AND ECM.

1. The shift lever has three connectors.

   • 8 Pin Connector

   • 6 Pin Connector

   • 4 Pin Connector

2. At the shifter, disconnect the 8-pin harness connector "C-C52". The six pin harness connector remains connected to the shifter 6 pin connector. The shifter 4 pin connector remains jumpered between pins 3 and 4.

3. Refer to the schematic of the shifter. Connect two jumper wires from the ECM connectors to frame ground, in order to simulate each position of the shifter. Use the 7X-1710 Multimeter Probe in order to make the connections. If a particular position is already suspect, begin with the wires for that position.

4. Monitor the status of the shifter on the ET screen.

Expected Result:

As each combination of contacts is grounded, the ET screen displays the corresponding shifter position.

Results:

• OK - As each combination of contacts is grounded, the ET screen displays the corresponding shifter position. The ECM and harness appear to be working correctly.

  Repair: Replace the shifter.

  STOP

• NOT OK - One of the combination of contacts is incorrect. The wiring harness or the ECM is not working correctly. Proceed to Test Step 4.

Test Step 4. CHECK THE ECM.

1. Open the machine service disconnect switch.

2. Based on the information in table 2 remove the corresponding wires from the machine ECM harness connectors "C-C12" and "C-C13". Use the shifter schematic for reference. Remove all of the wires shown in table 2, and place DT sockets into the connectors. Wire the sockets in a way that allows for individual connection to frame ground. Be sure that the wires cannot accidentally touch frame ground.

3. Close the machine service disconnect switch. Power up the machine with the key in the run position, and connect and start up the ET service tool.

4. Select the power train ECM and go to status screen 4.

5. Monitor the status of the shifter on the ET screen.

Expected Result:

As each combination of contacts is grounded, the ET screen displays the corresponding shifter position.

Results:

• OK - As each combination of contacts is grounded, the ET screen displays the corresponding shifter position. The ECM is working properly. The wiring harness may have failed.

  Repair: Repair the wiring harness or replace the wiring harness.

  STOP

• NOT OK - One of the combinations of contacts does not cause the proper status to be displayed. The ECM may have failed.

  Repair: Clean the contacts for the ECM harness connectors. Is unlikely that the ECM has failed. Exit this procedure and perform this entire procedure again. If the problem remains, replace the ECM. Is preferable to show that the new ECM corrects the problem and that the suspect ECM demonstrates the problem.

  STOP

Test Step 5. VERIFY SHIFT LEVER REMOTE FNR SWITCH FUNCTIONALITY.

1. Place shift lever on the steering column in Neutral and First Gear.

2. At the shifter 4 pin connector, remove the jumper wire between pin 3 and pin 4.

3. Reconnect the four pin connector "C-C50" from the cab harness onto the shifter 4 pin plug. Reconnecting the connectors will enable the remote FNR switch circuit for the shift handle.

4. Insure that the pins and sockets are seated properly, and that the connector mates correctly.

5. Place the remote FNR switch in the FORWARD position.

6. Verify that ET shows "F1" as desired gear.

7. Place the remote FNR switch in the REVERSE position.

8. Verify that ET shows "R1" as desired gear.

Expected Result:

As each combination is switched, the ET screen displays the corresponding gear and direction.

Results:

• STATUS CHANGES PROPERLY - The status of the shift lever position changes properly. Monitor the machine to see if the problem occurs. If the problem occurs, repeat the entire test procedure again.

  STOP

• STATUS INVALID - The status on the ET screen is "DATA FAULT" in either a particular position or all positions. Proceed to Test Step 6.

Test Step 6. VERIFY SHIFT LEVER REMOTE FNR HARNESS.

1. Ensure that the shift lever on the steering column is in Neutral and First gear.

   Note: The ECM needs to see Neutral, before each direction change. Test Step "H" below will always have to be repeated, before attempting to test for the proper signals indicating either Forward, or Reverse, direction.

2. Make sure that the cab harness 4 pin receptacle Connector "C-C50" is connected to the shifter 4 pin plug.

3. Disconnect the six pin connector "C-C23" that goes to the remote FNR switch assembly.

4. On the connector, place a jumper wire from pin 1 202-BK(Black) to pin 4 G787-GN(Green).

5. Verify that ET shows "F1" as the desired gear.

6. Move the jumper wire connection so that pin 1 202-BK(Black) connects to pin 6 G788-YL(Yellow).

7. Verify that ET shows "R1" as the desired gear.

8. Move the jumper wire connection so that pin 1 202-BK(Black) connects to pin 5 P916-OR(Orange).

9. Verify that ET shows "N1" as the desired gear.

Expected Result:

As each jumper pin combination is checked, the ET screen displays the corresponding gear and direction.

Results:

• STATUS CHANGES PROPERLY. - The status of the shift lever position changes properly. The harness from the remote FNR switch assembly to the ECM is working correctly.

  Repair: Replace the remote FNR switch assembly.

  STOP

• STATUS ALWAYS INVALID. - The status on the ET screen is "DATA FAULT" no matter which wire is jumpered to pin 1. The common signal pin 1 202-BK(Black) may have lost connection to machine ground. The wiring harness may have failed.

  Repair: Repair, or replace, the wiring harness.

  STOP

• STATUS INVALID WHEN A PARTICULAR WIRE IS JUMPERED. - The status on the ET screen is "DATA FAULT" when a particular wire is jumped to pin 1. The wiring harness may have failed.

  Repair: Repair or relace the wire that generated the "DATA FAULT" result, or replace the wiring harness.

  STOP