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| Illustration 1 | g01151637 |
Schematic of the transmission oil pressure sensor | |
This diagnostic code is associated with the transmission oil pressure sensor. This diagnostic code is recorded when the Power Train/Chassis Electronic Control Module (ECM) has determined that the voltage of the sensor as being below normal. The sensor is a component that produces a Pulse Width Modulated (PWM) signal output.
The PWM output frequency of the sensor is approximately 5000 Hz. The duty cycle of the signal varies as the sensor moves.
The possible causes of this diagnostic code are listed below:
- A shorted harness.
- A failed sensor.
- The ECM may have 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 04 is active before performing this procedure.
System Response:
The oil pressure for the transmission is unknown. The ECM will engage the parking brake. The parking brake will operate properly when the diagnostic code is corrected.
Test Step 1. CHECK THE SENSOR
- Turn the battery disconnect switch and the key start switch to the ON position.
- Ensure that the diagnostic code is active.
- Observe the status of the diagnostic code. Then, disconnect the machine harness from the sensor.
Expected Result:
If the sensor is not the cause of the diagnostic code, the diagnostic code remains active. If the sensor has failed, the diagnostic code is no longer active.
Results:
- YES - The diagnostic code remains active. The sensor is not faulty. The machine harness or the ECM may be faulty. Proceed to Test Step 2.
- NO - The diagnostic code is no longer active.
Repair: The machine harness is correct and the ECM is operating properly. The sensor has failed. Replace the sensor.
STOP
Test Step 2. CHECK THE SIGNAL CIRCUIT FOR A SHORT TO GROUND
- The sensor remains disconnected from the machine harness.
- Turn the battery disconnect switch and the key start switch to the OFF position.
- Disconnect the machine harness connector J1 and J2 from the ECM.
- Measure the resistance from J2-10 (wire X730-BR) to all source of ground.
Expected Result:
The resistance should be greater than 5 ohms.
Results:
- YES - The resistance is greater than 5 ohms. The machine harness is correct. Proceed to Test Step 3.
- NO - The resistance is not greater than 5 ohms. The machine harness has failed.
Repair: Repair the machine harness or replace the machine harness.
STOP
Test Step 3. CHECK IF THE DIAGNOSTIC CODE REMAINS
- Clean the contacts of the harness connectors.
- Reconnect all harness connectors.
- Turn the battery disconnect switch and the key start switch to the ON position.
- Operate the machine.
- Observe the status of the CID 0127 FMI 04 diagnostic code.
- Observe the status of the diagnostic code.
Expected Result:
The CID 0127 FMI 04 diagnostic code is active.
Results:
- YES - The CID 0127 FMI 04 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".
STOP
- NO - The CID 0127 FMI 04 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