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| Illustration 1 | g01302254 |
Schematic for the shift lever | |
The CID 0668 FMI 02 diagnostic code is recorded when the power train electronic control module (ECM) detects a problem with the shift lever:
- One of the signal wires is shorted to the + battery.
- One of the signal wires is shorted to ground.
- One of the signal wires has an open circuit.
- There is an internal failure in the shifter.
- The ECM has failed. This is unlikely.
Problems with the transmission direction and speed control lever will cause the machine to respond incorrectly to the actions of the lever. Some problems with the transmission direction and speed control lever will cause the transmission to remain in the present speed and direction when a problem is detected. Other problems with the transmission direction and speed control lever will cause the transmission to shift to neutral.
Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear the diagnostic codes when the original diagnostic code has been corrected.
Test Step 1. CHECK FOR PROPER GROUND AT THE SWITCH
- The machine harness remains connected to the shifter.
- Turn the key start switch and the disconnect switch to the OFF position.
- At the back of the harness connector for the switch, insert a 7X-1710 Multimeter Probe along the ground wire (contact 1).
- Measure the resistance from contact 1 to frame ground.
Expected Result:
The resistance is less than 5 ohms.
Results:
- OK - The resistance is less than 5 ohms. The ground circuit is correct. Proceed to Test Step 2.
- NOT OK - The resistance is greater than 5 ohms. The ground circuit in the machine harness has failed.
Repair: Replace the machine harness or repair the machine harness.
STOP
Test Step 2. CHECK FOR POWER AT THE SHIFT LEVER.
- Do not disconnect the harness connector from the shifter.
- Turn the key start switch and the disconnect switch to the ON position.
- At the back of the harness connector for the shifter, insert a 7X-1710 Multimeter Probe along the voltage supply wire (contact 3).
- Measure the voltage from contact 3 to frame ground.
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 + battery circuit in the machine harness has failed.
Repair: Replace the machine harness or repair the machine harness.
STOP
Test Step 3. CHECK THE HARNESS.
- Thoroughly inspect the connectors for the transmission direction and speed control lever and the connectors for the power train ECM.
- Visually inspect the harness wiring from the transmission direction and speed control lever to the power train ECM.
Expected Result:
The wiring harness appears to be undamaged.
Results:
- YES - The wiring harness appears to be undamaged. Proceed to Test Step 5.
- NO - The wiring harness is damaged.
Repair: Repair the wiring harness or replace the wiring harness.
STOP
Test Step 4. CHECK THE WIRES FOR A SHORT.
- Disconnect the shifter from the machine harness. Disconnect the machine harness connectors from the ECM.
- At the machine harness connector J1, locate the contacts for the shifter: J1-30, J1-14, J1-19, J1-23, J1-25, J1-26 and J1-13. One at a time, Place one probe from the multimeter in each socket that is listed above. While the probe is in each contact, measure the resistance between the contact and all of the wires that are used in machine harness connector J1 and J2. Repeat this procedure for each of the remaining contacts.
Expected Result:
Each resistance measurement is greater than 5000 ohms.
Results:
- YES - Each resistance measurement is greater than 5000 ohms. The machine harness is correct. Proceed to Test Step 5.
- NO - One of the resistance measurements is less than 5 ohms. There is a short in the machine harness. The short is in the circuit with the low resistance measurement.
Repair: Repair the machine harness or replace the machine harness.
STOP
Test Step 5. VIEW THE STATUS.
- Reconnect the machine harness connectors to the ECM.
- Use the Caterpillar Electronic Technician (ET) to view the status "Group 1 Gear Lever Parameters".
- Create a jumper wire in a Y configuration. Connect the single end of the jumper wire to contact 1 of the harness connector for the shifter.
- During the following tests, monitor the diagnostic code indicator in order to ensure that the diagnostic code does not become active.
- Connect the other two ends of the jumper wire to contact 5 and 7. On the Cat ET, the gear lever should read "1".
- Connect the other two ends of the jumper wire to contact 5 and 8. On the Cat ET, the gear lever should read "2".
- Connect the other two ends of the jumper wire to contact 5 and 9. On the Cat ET, the gear lever should read "3".
- Connect the other two ends of the jumper wire to contact 5 and 11. On the Cat ET, the gear lever should read "4".
- Connect the other two ends of the jumper wire to contact 6 and 7. On the Cat ET, the gear lever should read "1R".
- Connect the other two ends of the jumper wire to contact 6 and 8. On the Cat ET, the gear lever should read "2R".
- Connect the other two ends of the jumper wire to contact 6 and 9. On the Cat ET, the gear lever should read "3R".
- Connect the other two ends of the jumper wire to contact 6 and 11. On the Cat ET, the gear lever should read "4R".
- Connect the other two ends of the jumper wire to contact 11 and 12. On the Cat ET, the gear lever should read "N".
Expected Result:
All of the positions are displayed correctly and the diagnostic code is NOT present.
Results:
- OK - All of the positions are displayed correctly and the diagnostic code is NOT present.
Repair: Replace the shifter.
STOP
- NOT OK - While the jumper wire is in one of the positions, incorrect readings appear on the Cat ET screen and the diagnostic code is present. The ECM may have failed.
Repair: Recheck the wires that caused the reading to be incorrect. Repeat the test for the CID 0668 FMI 02 diagnostic code. If the cause of the diagnostic code is not found, replace the power train ECM. Refer to Testing and Adjusting, "Electronic Control Module (Power Train) - Replace" for more information on replacing the power train ECM.
STOP