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| Illustration 1 | g02580319 |
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Connections of the "Secondary Steering Oil Flow switch" | |
This diagnostic code is associated with the "Secondary Steering Oil Flow" switch. The FMI 14 diagnostic code means that the "Transmission/Chassis ECM" has detected a fault in the switch. The ECM is programmed to check the status of the "Secondary Steering Oil Flow" switch as the key start switch is turned ON but prior to the beginning of the steering pump test. When the key start switch is in the ON position, the "Secondary Steering Oil Flow" switch is normally in the OPEN position. If the Transmission/Chassis ECM finds that the switch is in the CLOSED position prior to the steering pump test, the FMI 14 code will be logged. Prior to the beginning of the steering pump test the engine speed is zero.
Conditions that can cause this diagnostic code to be activated are listed below:
- The ground circuit for the switch is shorted in the machine harness.
- The switch has failed.
- The ECM has failed. A failure of the Transmission/Chassis ECM is unlikely.
Test Step 1. CHECK THE RESISTANCE OF THE SWITCH
- Turn the disconnect switch and the key start switch to the OFF position.
- Disconnect the machine harness connector from the "Steering Oil Flow" switch.
- At the connector for the sender, measure the resistance between the contact 1 and the contact 2.
Expected Result:
The resistance measurement should be greater than 5000 ohms.
Results:
- OK - The resistance measurement is greater than 5000 ohms. The switch is OK. Proceed to Test Step 2.
- NOT OK - The resistance measurement is less than 5000 ohms. The "Steering Oil Flow" switch has failed.
Repair: Replace the "Steering Oil Flow" switch. Ensure that the new switch corrects the problem.
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Test Step 2. CHECK THE CONTROL AND THE HARNESS
- Turn the disconnect switch and the key start switch to the OFF position.
- Disconnect the machine harness connector from the "Secondary Steering Oil Flow" switch.
- Disconnect the J1 and J2 connectors from the Transmission/Chassis ECM.
- At the machine harness connector for the switch, measure the resistance from signal contact 1 (wire R852-YL(Yellow)) to all of the other contacts that are used in connectors J1 and J2 for the Transmission/Chassis ECM.
Expected Result:
Each resistance measurement is greater than 5000 ohms.
Results:
- OK - Each resistance measurement is greater than 5000 ohms. The supply circuit is not shorted to another circuit in the machine harness. Proceed to Test Step 3.
- NOT OK - One or more of the resistance measurements is less than 5000 ohms. There is a short in the machine harness.
Repair: The power supply circuit is shorted to another circuit in the machine harness. Refer to the complete Electrical System Schematic of the machine. Examine the supply circuit to determine the location of the problem.
For information on testing for short circuits and finding short circuits, refer to Testing and Adjusting, "Wiring Harness (Short Circuit) - Test". Repair the machine harness or replace the machine harness.
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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 securely.
- Turn the disconnect switch and the key start switch to the ON position.
- Operate the machine.
- Check the status of the CID 3401 FMI 14 diagnostic code.
Expected Result:
The CID 3401 FMI 14 diagnostic code is not active.
Results:
- OK - The CID 3401 FMI 14 diagnostic code is not active. The diagnostic code does not exist at this time. The initial diagnostic code was probably caused by a poor connection or a short at one of the connectors that was disconnected and reconnected. Resume normal operation.
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- NOT OK - The CID 3401 FMI 14 diagnostic code is active. The diagnostic code has not been corrected. The ECM may have failed.
Repair: Check the circuit for the switch again. Use the Cat Electronic Technician (ET) service tool to perform a wiggle test on the machine wiring harness. The wiggle test can detect momentary or intermittent shorts or opens in the machine wiring harness.
If the cause cannot be found, the ECM 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 Machine ECM. Refer to Testing and Adjusting, "Electronic Control Module (ECM) - Replace".
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