Illustration 1 | g01143586 |
Schematic of the parking brake pressure switch |
This diagnostic code is associated with the parking brake pressure switch. The switch is connected to two inputs of the ECM. One contact is open and the other contact is grounded during proper operation.
This FMI 03 means that the ECM has determined that the normally open contact and the normally closed contact are open.
Note: The following test procedure may create other diagnostic codes. Ignore these diagnostic codes and clear the diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code of CID 0627 FMI 03 is active before performing this procedure.
Test Step 1. CHECK THE GROUND CIRCUIT OF THE SWITCH IN THE HARNESS
- Turn the key start switch and the disconnect switch to the OFF position.
- Disconnect the machine harness connector from the switch.
- Measure the resistance between frame ground (wire 202-BK(Black)) of the machine harness and the contact A (wire 202-BK(Black)).
Expected Result:
The resistance is less than 5 ohms.
Results:
- YES - The resistance is less than 5 ohms. The circuit is correct. Proceed to Test Step 2.
- NO - The resistance is greater than 5 ohms. The circuit is open. The machine harness has failed.
Repair: Repair the machine harness or replace the machine harness.
STOP
Test Step 2. CHECK THE HARNESS
- Turn the disconnect switch and the key start switch to the OFF position.
- The machine harness remains disconnected from the switch.
- Disconnect the machine harness connectors from the ECM.
- Measure the resistance between contacts J2-53 (wire D735-PK(Pink)) and J2-52 (wire D756-YL(Yellow)) of the machine harness to all the contacts that are used in machine harness connectors for the ECM.
Expected Result:
Each resistance measurement is greater than 5 ohms.
Results:
- YES - Each resistance measurement is greater than 5 ohms. Proceed to Test Step 3.
- NO - One or more of the resistance measurements are less than 5 ohms. The harness has failed. The short is between J2-53 (wire D735-PK(Pink)) and the circuit with the lowest resistance or the short is between J2-52 (wire D756-YL(Yellow)) and the circuit with the lowest resistance.
Repair: Repair the wiring harness or replace the wiring harness.
STOP
Test Step 3. CHECK THE SWITCH CIRCUITS IN THE HARNESS
- The machine harness remains disconnected from the ECM and the switch.
- At the harness connector for the switch, connect a jumper wire between contact B (wire D756-YL(Yellow)) and contact C (wire D735-PK(Pink)).
- At the harness connector for the ECM, measure the resistance from contact J2-53 (wire D735-PK(Pink)) to contact J2-52 (wire D756-YL(Yellow)).
Expected Result:
The resistance is less than 5 ohms.
Results:
- YES - The resistance is less than 5 ohms. Proceed to Test Step 4.
- NO - The resistance is greater than 5 ohms. The circuit is open.
Repair: The machine harness has failed. Repair the machine harness or replace the machine harness.
STOP
Test Step 4. CHECK THE OPERATION OF THE SWITCH
- The machine harness remains disconnected from the switch.
- Connect one lead from a multimeter to contact A of the harness connector on the switch.
- Connect the other lead from a multimeter to contact B of the harness connector on the switch.
- Measure the resistance between contact A and contact B . Note the resistance.
- Disconnect the lead from contact B and connect the lead to contact C.
- Measure the resistance between contact A and contact C.
Expected Result:
The resistance from contact A to contact C is less than 5 ohms. The resistance from contact A to contact B is greater than 5 ohms.
Results:
- YES - The resistance from contact A to contact C is less than 5 ohms. The resistance from contact A to contact B is greater than 5 ohms. Proceed to Test Step 5.
- NO - The resistance measurements do not differ. The switch has failed.
Repair: Replace the switch.
STOP
Test Step 5. CHECK THE OPERATION OF THE SWITCH
- The machine harness remains disconnected from the switch.
- Activate the switch.
- Connect one lead from a multimeter to contact A (wire 202-BK(Black)) of the harness connector on the switch.
- Connect the other lead from a multimeter to contact B (wire D756-YL(Yellow)) of the harness connector on the switch.
- Measure the resistance between contact A and contact B. Note the resistance.
- Disconnect the lead from contact B and connect the lead to contact C.
- Measure the resistance between contact A and contact C.
Expected Result:
The resistance from contact A to contact B is less than 5 ohms. The resistance from contact A to contact C is greater than 5 ohms.
Results:
- YES - The resistance from contact A to contact B is less than 5 ohms. The resistance from contact A and contact C is greater than 5 ohms. These measurements are opposite of the measurements from the previous Test Step. The switch is operating correctly. Proceed to Test Step 6.
- NO - The resistance measurements do not differ for both contacts, or the measurements have not changed from the previous Test Step. The switch has failed.
Repair: Replace the switch.
STOP
Test Step 6. CHECK IF THE DIAGNOSTIC CODE REMAINS
- Inspect the contacts of the harness connectors and clean the connectors.
- Reconnect all harness connectors.
- Turn the disconnect switch and the key start switch to the ON position.
- Operate the machine.
- Determine if CID 0627 FMI 03 is present.
Expected Result:
The CID 0627 FMI 03 is active.
Results:
- YES - The CID 0627 FMI 03 is active. The diagnostic code has not been corrected. The ECM may have failed.
Repair: The ECM is unlikely to have failed. Exit this procedure and perform this procedure again. If the cause of the diagnostic code is not found, replace the ECM. Refer to Testing and Adjusting, "Electronic Control Module (ECM) - Replace" for the machine that is being serviced.
STOP
- NO - The CID 0627 FMI 03 is not active. The diagnostic code does not exist at this time.
Repair: 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. Resume normal machine operation.
STOP