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| Illustration 1 | g01758433 |
Blade Tilt (X-axis Left/Right) position sensor schematic | |
A CID 1079 diagnostic code is associated with the Blade Tilt (X-axis Left/Right) position sensor for the Blade tilt left and right commands. An FMI 04 indicates the machine ECM has found the voltage in the sensor circuit below normal.
Possible causes for this diagnostic code are:
- Failed sensor.
- Sensor signal circuit shorted to ground.
- Failed machine ECM. This condition is unlikely.
Note: Poor connections often cause problems in electrical circuits. Before performing this procedure, inspect all of the harness connectors involved in the circuit. Verify that all circuit connections are clean, secure, and in good condition. If a problem is found with any of the connections: correct the problem, and verify that diagnostic code CID 1079 FMI 04 is still active, before performing the following procedures.
System Response:
This diagnostic code will disable the Blade tilt left and right functions.
Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes now, but clear those codes after the original diagnostic code has been corrected.
Test Step 1. CHECK THE SENSOR, THE ECM, AND THE MACHINE HARNESS
- Turn the disconnect switch and the key start switch to the OFF position.
- Disconnect the harness connector from the Blade Tilt (X-axis Left/Right) position sensor.
- Turn the key start switch and the disconnect switch to the ON position.
- Observe the status of the diagnostic code.
Expected Result:
The 1079 FMI 04 diagnostic code remains active.
Results:
- YES - The diagnostic code remains active. The sensor is not the problem. Go to Test Step 2.
- NO - The diagnostic code is no longer active, and has been replaced by an active CID 1079 FMI 03 diagnostic code. The sensor has failed.
Repair: Replace the sensor.
Go to Test Step 3.
Test Step 2. CHECK THE SENSOR OUTPUT CIRCUIT FOR A SHORT
- Turn the disconnect switch and the key start switch to the OFF position.
- The harness connector stays disconnected from the sensor.
- Disconnect both the J1 and J2 harness connectors from the machine ECM.
- At the J2 machine harness connectors for the ECM, measure resistance from sensor signal output contact J2-42 (wire H711-GN) to all other J1 and J2 contacts used in both connectors.
Expected Result:
Each resistance measurement is greater than 5000 ohms.
Results:
- YES - Each resistance measurement is greater than 5000 ohms. Go to Test Step 3.
- NO - One or more resistance measurements is less than 5 ohms. There is a short in the harness.
Repair: The short is between wire H711-GN and the wire with the low resistance measurement. Repair or replace the harness.
Go to Test Step 3.
Test Step 3. CHECK THE STATUS OF THE DIAGNOSTIC CODE
- Reconnect all disconnected machine harness connectors. Make sure that all the connectors are clean, and fully seated. Observe that the clips for each connector are securely fastened.
- Turn the disconnect switch and the key start switch to the ON position.
- Clear all inactive diagnostic codes.
- Operate the machine.
- Check the status of the CID 1079 FMI 04 diagnostic code.
Expected Result:
The diagnostic code is not active.
Results:
- YES - The diagnostic code is no longer active and does not exist at this time.
Repair: Return the machine back to normal operations.
STOP
- NO - The diagnostic code is still active. The problem has not been corrected. The ECM may have failed.
Repair: If you have not inspected the harness connectors in a previous Test Step, do that now.Clean the contacts of the harness connectors. Check the wires for damage to the insulation 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.Perform a "wiggle test" on the sensor circuit of the machine wiring harness, using the Caterpillar Electronic Technician service tool. The "wiggle test" can be used to detect open or shorted connections in the machine wiring harness.Reconnect all harness connectors. Make sure that the connectors are fully seated. Observe that the clips for each connector are fastened.Perform Test Step 3 again.If the problem was again not found, and the original code is still active, the machine ECM may have failed.Prior to replacing an ECM, always contact your Dealership Technical Communicator for possible consultation with Caterpillar, or with the Dealer Solutions Network. This consultation may greatly reduce repair time.If the ECM needs to be replaced, see Testing and Adjusting, "Electronic Control Module (ECM) - Replace".
STOP