AD30 and AD55 Underground Articulated Trucks Power Train Electronic Control System Caterpillar

Illustration 1	g00743230
Schematic of the transmission gear position sensor

This diagnostic code is associated with the transmission gear position sensor. This diagnostic code is recorded when the Power Train/Chassis Electronic Control Module (ECM) reads erratic data from the transmission gear position sensor.

The possible causes of this diagnostic code are listed:

• A shorted harness or an open harness

• The sensor has failed.

• The ECM has failed.

This FMI 02 is recorded when the ECM receives an incorrect signal or erratic data from the sensor.

Note: The following test procedure may create other diagnostic codes. Ignore these diagnostic codes and clear the diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code of CID 0700 FMI 02 is active before performing this procedure.

System Response:

The sensor for the transmission gear is unavailable. The lockup clutch is forced to the off position and the machine will not shift. After the diagnostic code has been corrected, the machine will shift normally. The transmission will return to the gear that is currently selected by the position of the shift lever, and the transmission output speed.

Test Step 1. CHECK THE BATTERY VOLTAGE.

1. Turn the battery disconnect switch and the key start switch to the ON position.

2. At the connector for the sensor, measure the voltage from contact 4 to frame ground.

Expected Result:

The voltage should be +battery.

Results:

• OK - The voltage that is measured is approximately +battery. Proceed to Test Step 2.

• NOT OK - The voltage that is measured is not approximately +battery.

  Repair: Repair the machine harness or replace the machine harness. Verify that the repair corrects the problem.

  STOP

Test Step 2. CHECK THE GROUND CIRCUIT.

1. The key start switch and the battery disconnect switch remain in the OFF position.

2. At the connector for the sensor, measure the resistance from contact 10 to frame ground.

Expected Result:

The resistance should be less than 5 ohms.

Results:

• OK - The resistance is less than 5 ohms. Proceed to Test Step 3.

• NOT OK - The resistance is greater than 5 ohms.

  Repair: There is an open in the ground circuit. Repair the harness or replace the harness. Verify that the repair corrects the problem.

  STOP

Test Step 3. CHECK THE HARNESS.

1. Turn the key start switch and the battery disconnect switch to the OFF position.

2. Disconnect the sensor from the machine harness.

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

4. Place the monitor in Submode 7.5 “Inputs Of The Transmission Gear Position Sensor”.
   Show/hide table

   Illustration 2	g00535843
   Display Area Of Contacts J1-36, J1-33, J1-32, J1-31, J1-30 and J1-29

5. At the sensor, use a jumper wire to briefly connect the following contacts of the sensor to frame ground. As each contact is briefly connected to frame ground, the corresponding digit should display a “0” when ground is applied to the contact. Observe the status on the display of the monitor. See the following table.

Expected Result:

The display shows the correct indication for each contact.

Results:

• OK - The display shows the correct indication for each contact.

  Repair: The sensor has failed. Replace the sensor. Verify that the sensor corrects the problem.

  Proceed to Test Step 4.

• NOT OK - The display does not show the correct indication for each contact.

  Repair: The problem is in the circuit that did not display a correct indication. Repair the circuit or replace the harness.

  Proceed to Test Step 4.

Test Step 4. CHECK IF THE DIAGNOSTIC CODE REMAINS

1. Inspect the contacts of the harness connectors and clean the harness connectors.

2. Reconnect all the harness connectors.

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

4. Operate the machine.

5. Check the status of the CID 0700 FMI 02.

Expected Result:

The CID 0700 FMI 02 is active.

Results:

• YES - The CID 0700 FMI 02 is active. The diagnostic code has not been corrected. The ECM may have failed.

  Repair: It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. If the cause of the diagnostic code is not found, replace the ECM. Refer to Systems operation, Troubleshooting, Testing and Adjusting, "Electronic Control Module (ECM) - Replace" for the machine that is being serviced.

  STOP

• NO - The CID 0700 FMI 02 is not active. The diagnostic code does not exist at this time.

  Repair: The initial diagnostic code was probably caused by a poor electrical connection or a short at one of the harness connectors that was disconnected and reconnected. Resume normal machine operation.

  STOP