Illustration 1 | g02347317 |
Schematic of the steering pressure sensor 2 |
The CID 2829 diagnostic code is associated with the main hydraulic pump pressure sensor. The sensor produces a PWM signal. The signal wire (K777-GY) connects to contact J2-50 of the Implement ECM 2. The FMI 04 diagnostic code is recorded when the Implement ECM 2 reads the signal from the sensor (wire K777-GY) as being shorted to ground.
The possible causes of this diagnostic code are listed below:
- The signal circuit (wire K777-GY) is shorted to ground.
- The pressure sensor has failed.
- The ECM has failed. This condition is unlikely.
Note: Ensure that the CID 2829 FMI 04 diagnostic code is active. This procedure can cause new diagnostic codes to be recorded. Ignore these created diagnostic codes. When the procedure is completed, clear the created diagnostic codes.
Note: Ensure that all required calibrations are performed after the diagnostic code has been corrected.
Test Step 1. CHECK THE SENSOR.
- Turn the disconnect switch and the key start switch to the OFF position.
- Disconnect the sensor from the machine harness.
- Turn the disconnect switch and the key start switch to the ON position.
- Observe the status of the diagnostic code.
Expected Result:
The CID 2829 FMI 04diagnostic code remains active and does not change.
Results:
- YES - The CID 2829 FMI 04diagnostic code remains active and does not change. The sensor is not causing the problem. Proceed to test step 2.
- NO - The CID 2829 FMI 04 diagnostic code is no longer active, and has changed into an active CID 2829 FMI 03 diagnostic code. The sensor has failed.
Repair: Replace the sensor. Verify that the new sensor corrects the problem.
STOP
Test Step 2. CHECK THE SIGNAL CIRCUIT FOR A SHORT TO GROUND.
- The sensor remains disconnected from the machine harness.
- Turn the key start switch and the disconnect switch to the OFF position.
- Disconnect the J2 machine harness connector from the ECM.
- At the J2 machine harness connector, measure the resistance from contact J2-50 (wire K777-GY) to ground.
Expected Result:
The resistance is greater than 5000 ohms.
Results:
- YES - The resistance is greater than 5000 ohms. The Implement ECM 2 may have failed.
Repair: The failed condition of the ECM is unlikely. Recheck the status of the diagnostic code. If the diagnostic code remains present, exit this procedure and perform this procedure again. If the cause of the diagnostic code is not found, replace the ECM. Contact the Technical Communicator for your dealership for possible consultation with Caterpillar. prior to replacing the ECM. This consultation may greatly reduce repair time. If the ECM requires replacement, refer to Troubleshooting, "Electronic Control Module (ECM) - Replace".
STOP
- NO - The resistance is less than 5000 ohms. The machine harness has failed. There is a short in the machine harness between the signal circuit and ground.
Repair: Repair the machine harness or replace the machine harness.
Proceed to Test Step 3
Test Step 3. CHECK THE STATUS OF THE DIAGNOSTIC CODE
- Inspect the harness connectors. Clean the contacts of the harness connectors. Check the wires for damage to the insulation that is caused by excessive heat, battery acid, or chafing.
- Perform a 45 N (10 lb) pull test on each of the wires that are associated with the sensor circuit.
- Reconnect all harness connectors. Make sure that the connectors are fully seated. Observe that the clips for each connector are fastened completely.
- Turn the disconnect switch and the key start switch to the ON position.
- Operate the machine.
- Determine if the CID 2829 FMI 14 diagnostic code is active.
Expected Result:
The CID 2829 FMI 14 diagnostic code is not active.
Results:
- YES - The CID 2829 FMI 14 diagnostic code is not active. The problem has been corrected.
Repair: The initial diagnostic code was probably caused by a poor electrical connection that was resolved when a harness connector was disconnected and reconnected. Resume normal machine operation.
STOP
- NO - The CID 2829 FMI 14 diagnostic code is still active. The problem has not been corrected.
Repair: Perform this test step again. If the problem has not been corrected, proceed with the following process. Use a Caterpillar Electronic Technician service tool and perform a wiggle test on the sensor circuit for the machine wiring harness of the machine. The wiggle test can be used to detect momentary short circuit connections. The wiggle test can also be used to detect open connections in the machine wiring harness.If a problem is not found in the machine harness, replace the pressure sensor. If the problem is still present after replacement of the sensor, the Implement ECM 2 may have failed.Prior to replacing an ECM, always contact the Technical Communicator at your dealership for possible consultation with Caterpillar. This consultation may greatly reduce repair time. If the cause of the diagnostic code is not found, replace the Implement ECM. Refer to Testing and Adjusting, "Electronic Control Module (ECM) - Replace".
STOP