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| Illustration 1 | g01948891 |
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Connections of the air conditioner clutch solenoid | |
This diagnostic code is associated with the air conditioner clutch solenoid. The FMI 03 diagnostic code means that the Brake ECM has determined that the voltage is above normal.
The possible causes of the diagnostic code are listed below:
- The solenoid has failed.
- The solenoid energizer circuit of the modulating valve is shorted to the +battery circuit.
- The diode that is used for the suppression of the voltage for the circuit has failed.
- The ECM has failed. This is unlikely.
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 of the connections in the circuit are clean and that all connections in the circuit are secure. If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing this procedure.
Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear these diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code of CID 2671 FMI 03 is active before performing this procedure.
Note: Use a digital multimeter for the measurements in this procedure.
Test Step 1. CHECK THE "ARC SUPPRESSOR" DIODE
- Locate a multimeter that is capable of testing the function of a diode. Set the meter to the function that is used for checking a diode.
- Remove the "arc suppressor" diode from the wiring harness.
- Place the red probe in the red terminal (positive terminal) of the multimeter.
- Place the black probe in the black terminal (negative terminal) of the multimeter.
- Connect the red probe of the meter to pin 2 of the "arc suppressor" diode.
- Connect the black probe of the meter to pin 1 of the "arc suppressor" diode.
- Observe the readout of the multimeter. The display will be between 0.5 VDC and 1.0 VDC.
- Reverse the order of the probes at the connectors.
- Observe the readout of the multimeter. The display will be between 0.5 VDC and 1.0 VDC.
Expected Result:
The readout of the meter is correct.
Results:
- OK - The readout of the meter is correct. Connect the "arc suppression" diode to the wiring harness. Proceed to Test Step 2.
- NOT OK -
Repair: The reading of the multimeter shows that the circuit is open. The diode should be replaced. Check the circuit once more after the diode is replaced.
STOP
Test Step 2. CHECK THE RESISTANCE OF THE "A/C CLUTCH" SOLENOID
- Remove the "A/C Clutch" solenoid from the wiring harness.
- Use a multimeter in order to measure the resistance across the terminals of the solenoid.
- Reverse the leads of the multimeter and measure the resistance across the terminals of the solenoid.
- The resistance across the terminals should measure more than 4 ohms and less than 16 ohms.
Expected Result:
The resistance measurement at the terminals of the solenoid are between 4 ohms and 16 ohms.
Results:
- OK - The resistance across the terminals of the solenoid are between 4 ohms and 16 ohms. Proceed to Test Step 3.
- NOT OK -
Repair: The resistance across the terminals of the solenoid are not correct. Replace the solenoid. Check the circuit after the solenoid has been replaced.
STOP
Test Step 3. CHECK THE SOLENOID CIRCUIT FOR A SHORT TO THE +BATTERY CIRCUIT.
- Turn the key start switch and the disconnect switch to the OFF position.
- Disconnect the machine harness from the solenoid and the Brake ECM.
- At the machine harness connector for the Brake ECM, measure the resistance from contact J2-10 (wire C510-WH(White)) to all contacts that are used in the machine harness connectors for the Brake ECM.
- At the machine harness for the AC Clutch relay, measure the resistance from contact D3(wire E554-PK(Pink)) to all contacts that are used in the machine harness connector for the "EIC" connector.
Expected Result:
Each resistance measurement should be greater than 5000 ohms.
Results:
- OK - Each resistance measurement is greater than 5000 ohms. The machine harness is correct. Proceed to test step 4.
- NOT OK - Each resistance measurement is not greater than 5000 ohms. There is a short in the machine harness. The short is between contact J2-10 (wire C510-WH(White)) and the circuit with the low resistance measurement. The short circuit can also exist between contact D4 of the AC clutch relay and the "EIC" connector. Repair the machine harness or replace the machine harness.
STOP
Test Step 4. CHECK IF THE DIAGNOSTIC CODE IS STILL ACTIVE.
- Inspect the harness connectors. Clean the contacts of the harness connectors and 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 circuit. - Reconnect all harness connectors in order to make sure that the connectors are fully seated. Also, make sure that 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 diagnostic code is active.
Expected Result:
The diagnostic code is active.
Results:
- YES - The diagnostic code is active. The problem has not been corrected.
Repair: Check the circuit again. It is unlikely that the Brake has failed. Exit this procedure and perform this procedure again. Prior to replacing an ECM, always contact your dealership for possible consultation with Caterpillar. This consultation may greatly reduce repair time. If the ECM requires replacement, refer to Testing and Adjusting, "Electronic Control Module (ECM) - Replace".
STOP
- NO - The diagnostic code is not active. The initial diagnostic code was probably caused by a poor electrical connection or a short at one of the harness connectors that was disconnected and reconnected. The problem does not exist at this time. Resume normal machine operation.
STOP