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| Illustration 1 | g02777076 |
Schematic of the Low Idle Switch | |
This diagnostic code is associated with the Low Idle Switch. This switch has two inputs to the Premium Cluster: normally open (wire K974-PU) and normally closed (wire K973-PK). During normal operation, one switch input is open and the other input is grounded. This diagnostic code is communicated on the Machine ECM via CAN Data link.
The FMI 07 diagnostic code means that the Machine ECM has determined that the switch has been in the Closed position for greater an extended duration of time.
Some of the possible causes of an FMI 07 are listed below:
- The switch is stuck in a position
- The switch has failed
- The Machine ECM may have failed. This condition 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 2977 FMI 07 is active before performing this procedure.
Note: Use the 146-4080 Digital Multimeter for the measurements in this procedure.
System Response:
The machine transmission will stay in low idle.
Test Step 1. CHECK THE SWITCH
- Turn the key start switch and the disconnect switch to the OFF position.
- Disconnect the machine harness connector from the switch.
- Use a Multimeter to verify the proper operation of the switch. Refer to Table 1 for the switch operation.
Show/hide table
Table 1 Switch Status Contacts 8 to 10 Contacts 9 to 10 Switch Not Actuated Less than 5 ohms Greater than 5000 ohms Switch Actuated Greater than 5000 ohms Less than 5 ohms
Expected Result:
The switch is operating correctly.
Results:
- OK - The switch is operating correctly. Proceed to Test Step 2.
- NOT OK - The switch is not functioning correctly. There is an internal failure in the switch.
Repair: Replace the switch.
STOP
Test Step 2. CHECK THE N/O SWITCH CIRCUIT IN THE HARNESS
- The key start switch and the disconnect switch remain in the OFF position.
- Disconnect the machine harness connectors from the ECM.
The switch remains disconnected.
- At the machine harness connector for the ECM, measure the resistance from contact J2-14 K974-PU to contact J2-13 K973-PK.
Expected Result:
The resistance is greater than 5000 ohms.
Results:
- OK - The resistance is greater than 5000 ohms. The machine harness is correct. Proceed to Test Step 4.
- NOT OK - The resistance is less than 5 ohms. The circuit is open.
Repair: Repair the machine harness or replace the machine harness.
STOP
Test Step 3. CHECK THE N/O AND GROUND CIRCUIT OF THE SWITCH IN THE HARNESS
- The key start switch and the disconnect switch remain in the OFF position.
- The machine harness connectors remain disconnected from the ECM and the switch.
- At the connector for the switch, place a jumper between contact 9 and 10.
- At the machine harness connector for the ECM, measure the resistance from contact J2-14 K974-PU to contact J2-22 J878-YL.
Expected Result:
The resistance is less than 5 ohms.
Results:
- OK - The resistance is less than 5 ohms. The machine harness is correct. Proceed to Test Step 4.
- NOT OK - The resistance is greater than 5000 ohms. The circuit is open.
Repair: Repair the machine harness or replace the machine harness.
STOP
Test Step 4. CHECK IF THE DIAGNOSTIC CODE IS STILL ACTIVE
- Inspect the contacts and clean the contacts of the harness connectors.
- Reconnect all harness connectors.
- Turn the disconnect switch and the key start switch to the ON position.
- Operate the machine.
- Determine if the CID 2977 FMI 07 diagnostic code is active.
Expected Result:
The CID 2977 FMI 07 diagnostic code is not active.
Results:
- YES - The CID 2977 FMI 07 diagnostic code is not active. The problem has not been corrected. The ECM may have failed.
Repair: The initial diagnostic code may have been 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
- NO - The CID 2977 FMI 07 diagnostic code is active. The problem has not been corrected. The ECM may have failed.
Repair: Exit this procedure and perform this procedure again.If all possible causes of the problem have been investigated and no problem can be found, you may need to replace the Machine ECM.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 and expense. If the ECM must be replaced, refer to Testing and Adjusting, "Module - Replace"
STOP