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| Illustration 1 | g01254084 |
Schematic of the transmission oil pressure sensor | |
This diagnostic code is associated with the transmission oil pressure sensor. The FMI 08 means that the ECM has determined that the signal frequency or the signal pulse width is not within the expected range.
The output frequency of the sensor is approximately 5000 Hz. The duty cycle of the signal varies as the pressure sensor moves.
The possible causes of this diagnostic code are:
- The sensor has failed.
- Intermittent connections or poor connections.
- Mechanical devices are loose.
- The ECM has failed. This is unlikely.
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. Ensure that the diagnostic code of CID 0127 FMI 08 is active before performing this procedure.
Test Step 1. CHECK FOR POWER AT THE SENSOR
- Disconnect the harness connector from the sensor.
- Turn the key start switch and the disconnect switch to the ON position.
- At the machine harness connector for the sensor, measure the voltage between connector contact A (wire 113-OR) and frame ground.
Expected Result:
The voltage is approximately 24 V.
Results:
- YES - The voltage is approximately 24 V. Proceed to Test Step 2.
- NO - The voltage is not approximately 24 V. The circuit is open.
Repair: Check circuit breaker 7. Repair the machine harness or replace the machine harness.
STOP
Test Step 2. CHECK FOR AN OPEN HARNESS (SIGNAL)
- Turn the disconnect switch and key start switch to the OFF position.
- The sensor remains disconnected.
- Disconnect the machine harness from the ECM.
- Check the resistance of the signal circuit from contact J2-25 wire (X730-BR) to contact C wire (X730-BR) of the sensor.
Expected Result:
The resistance is less than 5 ohms.
Results:
- YES - The resistance is less than 5 ohms. The signal circuit is correct. Proceed to Test Step 3.
- NO - The resistance is greater than 5 ohms. The signal circuit has failed.
Repair: Repair the machine harness or replace the machine harness.
STOP
Test Step 3. CHECK FOR AN OPEN HARNESS (GROUND)
- The sensor and the ECM remain disconnected from the machine harness.
- The disconnect switch and the key start switch remain in the OFF position.
- At the machine harness connector for the sensor, measure the resistance between contact B (wire 202-BK) and frame ground.
Expected Result:
The resistance is less than 5 ohms.
Results:
- YES - The resistance is less than 5 ohms. The harness resistance is correct. Proceed to Test Step 4.
- NO - The resistance is greater than 5 ohms. The ground circuit in the harness is faulty.
Repair: There is an open circuit between ground contact B (wire 202-BK) and ground. Repair the machine harness or replace the machine harness.
STOP
Test Step 4. CHECK FOR A SHORTED HARNESS
- The sensor and the ECM remain disconnected from the machine harness.
- The disconnect switch and key start switch remain in the OFF position.
- At the machine harness connector for the ECM, measure the resistance between signal contact J2-25 wire (X730-BR) and all other J1 and J2 contacts.
Expected Result:
The resistance is greater than 5 ohms.
Results:
- YES - The resistance is greater than 5 ohms. The harness circuit resistance is correct. Proceed to Test Step 5.
- NO - The resistance is less than 5 ohms. The machine harness has failed.
Repair: Repair the machine harness or replace the machine harness.
STOP
Test Step 5. CHECK IF THE DIAGNOSTIC CODE REMAINS
- Inspect the harness connectors and clean the contacts of the machine harness connectors.
- Reconnect all harness connectors.
- Turn the disconnect switch and the key start switch to the ON position.
- Operate the machine.
- Check the status of the CID 0127 FMI 08.
Expected Result:
The CID 0127 FMI 08 is not active.
Results:
- YES - The CID 0127 FMI 08 is not active. The diagnostic code does not exist at this time. The initial diagnostic code was probably caused by a poor connection or a short at one of the connectors that was disconnected and reconnected. Resume normal operation.STOP
- NO - The CID 0127 FMI 08 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 failure is not found, replace the ECM. Refer to Troubleshooting, Testing and Adjusting, "Electronic Control Module (ECM) - Replace".
STOP