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| Illustration 1 | g01268293 |
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Operator Present Switch connections | |
This diagnostic code is associated with the operator present switch. The switch supplies two, switch to ground type inputs to the Implement ECM and to the Transmission Chassis ECM. The ECM expects one of the two switch inputs to be grounded at all times. When the ECM detects that neither of the switch inputs is grounded, the ECM will activate an FMI 03 diagnostic code for voltage above normal.
Possible conditions that can cause this diagnostic code are listed:
- One or both of the switch circuits is open in the machine harness.
- One or both of the switch inputs is shorted to a voltage source.
- The switch has failed.
- The ECM has failed. This is unlikely.
Note: Before performing this procedure, inspect the harness connectors that are involved in the circuit. Poor connections can often be the cause of a problem in an electrical circuit. Verify that all connections in the circuit are clean, secure and in good condition. If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing this procedure.
| Operator Present Switch Contact States | ||
| Operator Status | N/O Input J1-64 (wire U767-BU(Blue)) | N/C Input J1-63 (wire U766-BR(Brown)) |
| Operator Not Present | Open(1) | Closed(2) |
| Operator Present | Closed | Open |
| (1) | Open to ECM return J1-23 (A295-BK(Black) - ground). |
| (2) | Closed to ECM return J1-23 (A295-BK(Black) - ground). |
Note: The operator present switch provides two inputs to the Implement ECM and to the Transmission Chassis ECM. If one ECM has activated the diagnostic code and the other ECM has not activated the diagnostic code, most likely the switch is operating correctly. This condition would indicate that there is a problem in the machine harness. In either case, perform this procedure in order to find the cause of the problem.
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.
Test Step 1. CHECK THE SWITCH INPUT CIRCUITS FOR AN OPEN
- Turn the disconnect switch and the key switch to the OFF position.
- Disconnect the machine harness connector from the switch.
- At the machine harness connector for the switch, connect a jumper wire between the normally open (N/O) contact C (wire U767-BU(Blue)) and the normally closed (N/C) contact B (wire U766-BR(Brown)).
- Disconnect the machine harness connectors J1 and J2 from the Implement ECM.
- At the Implement ECM machine harness connector J1, measure the resistance between N/C contact J1-63 (wire U766-BR(Brown)) and N/O contact J1-64 (wire U767-BU(Blue)).
Expected Result:
Both of the resistance measurements are less than 5Ω.
Results:
- OK. - The resistance measurement is less than 5Ω. The switch input circuits are not open in the machine harness. Proceed to Test Step 2.
- NOT OK. - The resistance measurement is greater than 5Ω. One of the switch input circuits is open or has a poor connection in the machine harness.
Repair: There is an open or poor connection in switch input wire U766-BR(Brown) or switch input wire U767-BU(Blue). Check each switch input circuit individually in order to determine which circuit has the problem.
If both of the ECMs have activated this diagnostic code, there is most likely an open or a bad connection on the switch side of the machine harness splice connection for the signal wire.
If only one ECM has activated this diagnostic code, there is most likely an open or a bad connection on the ECM side of the machine harness splice connection for the switch circuit wire.
Refer to the complete machine Electrical System Schematic. Verify that all connection points in the suspected part of the circuits are clean, secure and in good condition. Repair the machine harness or replace the machine harness.
STOP
Test Step 2. CHECK THE SWITCH GROUND CIRCUIT FOR AN OPEN
The disconnect switch and the key switch remain in the OFF position. The machine harness connectors remain disconnected from the Implement ECM and the switch.
- At the machine harness connector for the switch, connect the jumper wire that was used in the last test step between the common ground contact A (wire A295-BK(Black)) and the normally closed (N/C) contact B (wire U766-BR(Brown)).
- At the Implement ECM machine harness connector J1, measure the resistance between common ground contact J1-23 (wire A295-BK(Black)) and N/C contact J1-63 (wire U766-BR(Brown)).
Expected Result:
The resistance measurement is less than 5Ω.
Results:
- OK. - The resistance measurement is less than 5Ω. The common ground circuit is not open in the machine harness. Proceed to Test Step 3.
- NOT OK. - The resistance measurement is greater than 5Ω. The ground common circuit is open or has a poor connection in the machine harness.
Repair: There is an open or poor connection in switch ground wire A295-BK(Black). Refer to the complete machine Electrical System Schematic. Check all of the connectors that are in the common ground circuit. Verify that all connection points for the circuit are clean, secure and in good condition. Repair the machine harness or replace the machine harness.
STOP
Test Step 3. CHECK THE HARNESS FOR A SHORT
The key start switch and the disconnect switch remain in the OFF position.
The switch and the connectors for the Implement ECM remain disconnected from the machine harness.
- Disconnect the jumper wire that was used in the last test step.
- At the Implement ECM machine harness connector J1, measure the resistance between contact J1-63 (wire U766-BR(Brown)) to all of the other contacts that are used in the J1 and J2 connectors for the ECM.
- At the Implement ECM machine harness connector J1, measure the resistance between contact J1-64 (wire U767-BU(Blue)) to all of the other contacts that are used in the J1 and J2 connectors for the ECM.
Expected Result:
Each resistance measurement is greater than 5kΩ.
Results:
- OK. - Each resistance measurement is greater than 5kΩ. The switch input circuits are not shorted in the machine harness. Proceed to Test Step 4.
- NOT OK. - One or more of the resistance measurements is less than 5kΩ.
Repair: There is a short circuit in a switch input circuit. The short is between the input circuit that measured the low resistance measurement to another circuit. Refer to the complete machine Electrical System Schematic. Check the connectors that are in the involved circuits. Verify that all connection points for the circuit are clean, secure and in good condition. Repair the machine harness or replace the machine harness.
STOP
Test Step 4. CHECK THE SWITCH OPERATION
The switch remains disconnected from the machine harness. The disconnect switch and the key switch remain in the OFF position.
- At the connector for the switch, measure the resistance (continuity) between common contact A and the switch N/C contact B when an operator is present in the operator seat and when no operator is present in the operator seat.
- At the connector for the switch, measure the resistance (continuity) between common contact A and the switch N/O contact C when an operator is present in the operator seat and when no operator is present in the operator seat.
Expected Result:
The switch continuity checks are correct according to the table at the beginning of this procedure.
Results:
- OK. - The continuity checks between common contact A to the switch contacts are correct. The switch is operating correctly. Proceed to Test Step 5.
- NOT OK. - The continuity checks between the common contact A to the switch contacts are not correct. The switch is not working correctly.
Repair: The operator present switch has failed. Replace the switch. After replacement of the switch, verify that the operation of the new switch is correct before operating the machine.
STOP
Test Step 5. CHECK THE STATUS OF THE DIAGNOSTIC CODE
- Inspect the harness connectors and 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 and the clips for each connector are completely fastened.
- Turn the disconnect switch and the key start switch to the ON position.
- Operate the machine.
- Determine if the CID 2113 FMI 03 diagnostic code is active.
Expected Result:
The CID 2113 FMI 03 diagnostic code is active.
Results:
- YES. - The CID 2113 FMI 03 diagnostic code is active. The problem has not been corrected.
Repair: Repeat this procedure. Use the Caterpillar Electronic Technician (ET) service tool, if available, in order to perform a "Wiggle Test" on the switch circuits in the machine wiring harness. The wiggle test can detect momentary or intermittent shorts or opens in the machine wiring harness.
If the cause of the problem is not found, the ECM may have failed. Prior to replacing an ECM, always contact your dealership's Technical Communicator for possible consultation with Caterpillar. This consultation may greatly reduce repair time. If the cause of the diagnostic code is not found, replace the ECM that has activated the diagnostic code. Refer to Testing and Adjusting, "Electronic Control Module (ECM) - Replace".
STOP
- NO. - The CID 2113 FMI 03 diagnostic code is not active. The problem does not exist at this time.
Repair: The initial diagnostic code was probably cause by a poor electrical connection or a short at one of the harness connectors that was disconnected and reconnected. Resume normal machine operation.
STOP