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| Illustration 1 | g03354609 |
Schematic of the brake accumulator oil pressure sensor for alert indicator | |
This diagnostic code is associated with the brake accumulator oil pressure sensor for alert indicator. This diagnostic code is recorded when the Power Train/Chassis Electronic Control Module (ECM) reads the voltage of the sensor circuit as being above normal for 2 hours continuously.
Possible causes of this diagnostic code are listed:
- Wire X778-PU is shorted to +battery.
- The sensor has failed.
- Wire X778-PU or 202-BK is open.
- The ECM has failed. This is unlikely.
Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear these diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code of CID 1272 FMI 03 is active before performing this procedure.
Note: Use the 146-4080 Digital Multimeter for the measurements in this procedure.
System Response:
The brake accumulator oil pressure is normal. The brake accumulator alert indicator will be on, the action lamp will come on, and the action alarm will sound.
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.
- At the machine harness connector for the sensor place a jumper wire from contact B (wire X778-PU) to contact C (wire 202-BK).
- The status of the diagnostic code is active and the status of the diagnostic code is not active as the jumper wire is installed and the jumper wire is removed.
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 remains not active.
Results:
- YES - The diagnostic code remains active the sensor has not failed. Proceed to Test Step 2
- NO - The diagnostic changes from an active state to an inactive state. The sensor has failed.
Repair: Repeat this test "CHECK THE SENSOR" in order to verify that the sensor has failed. Replace the sensor.
STOP
Test Step 2. CHECK FOR AN OPEN CIRCUIT
- Turn the key start switch and the battery disconnect switch to the OFF position.
- Disconnect the J1 and J2 machine harness connectors from the ECM.
- The jumper wire that was installed in the previous Test Step remains in place.
- At the J2 machine harness connector for the ECM, measure the resistance from the signal contact J2-60 (wire X778-PU) to frame ground.
Expected Result:
The resistance that is measured is less than 5 ohms.
Results:
- YES - The resistance that is measured is less than 5 ohms. Proceed to Test Step 3.
- NO - The resistance measurements is greater than 5 ohms. There is an open in the machine harness.
Repair: Repair the machine harness or replace the machine harness. Verify that the diagnostic code is no longer active.
STOP
Test Step 3. CHECK FOR A SHORT TO THE +BATTERY CIRCUIT
- The key start switch and the battery disconnect switch remain in the OFF position.
- Remove the jumper wire that was previously installed.
- The J1 and J2 machine harness connectors remain disconnected from the ECM.
- At the J2 machine harness connector for the ECM, measure the resistance from the signal contact J2-60 (wire X778-PU) to all possible sources of +battery.
Expected Result:
The resistance for each measurement should be greater than 5 ohms.
Results:
- YES - Each resistance measurement is greater than 5 ohms. The harness is correct. The ECM may have failed. Proceed to Test Step 4.
- NO - Each resistance measurement is not greater than 5 ohms. The machine harness has failed.
Repair: There is a short in the machine harness. The short is between the signal (wire X778-PU) and the wire with the low resistance measurement. Repair the machine harness or replace the machine harness.
STOP
Test Step 4. CHECK IF THE DIAGNOSTIC CODE REMAINS
- Inspect the contacts of the harness connectors and clean the harness connectors.
- Reconnect all the harness connectors.
- Turn the battery disconnect switch and the key start switch to the ON position.
- Operate the machine.
- Check the status of the CID 1272 FMI 03.
Expected Result:
The CID 1272 FMI 03 is active.
Results:
- YES - The CID 1272 FMI 03 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 1272 FMI 03 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