 | |
| Illustration 1 | g01227022 |
Schematic of the parking brake switch (pull-to-engage) | |
 | |
| Illustration 2 | g01227024 |
Schematic of the parking brake switch (push-to-engage) | |
Note: The following test procedure is applicable to the pull-to-engage parking brake switch and the push-to-engage parking brake switch.
This diagnostic code is associated with the parking brake 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 0070 FMI 03 is active before performing this procedure.
System Response:
The parking brake remains engaged when a failure exists for this diagnostic code.
Test Step 1. CHECK THE CIRCUIT FOR AN OPEN CIRCUIT
- Turn the key start switch and the disconnect switch to the OFF position.
- Disconnect the machine harness connector from the parking brake switch.
- Disconnect the machine harness connector from the ECM.
- At the machine harness connector for the switch, place a jumper wire from connector contact 2 (wire C976-YL) to connector contact 6 (wire G764-PK).
- At the harness connector for the ECM measure the resistance between connector contact 54 (wire C976-YL) and connector contact 55 (wire G764-PK).
Expected Result:
The resistance is less than 5 ohms.
Results:
- YES - The resistance is less than 5 ohms. The harness circuit is correct. Proceed to Test Step 2.
- NO - The resistance is greater than 5 ohms. The machine harness has failed.
Repair: Repair the machine harness or replace the machine harness.
STOP
Test Step 2. CHECK THE GROUND CIRCUIT
- The disconnect switch and the key start switch remain in the OFF position.
- The harness connectors for the ECM and the switch remain disconnected.
- Remove the jumper wire that was installed in the previous Test Step.
- At the harness connector for the switch, measure the resistance from connector contact 3 (wire 202-BK) to frame ground.
- At the harness connector for the switch, measure the resistance from connector contact 4 (wire 202-BK) to frame ground.
Expected Result:
The resistance is less than 5 ohms.
Results:
- YES - The resistance is less than 5 ohms. Proceed to Test Step 3.
- NO - The resistance is greater than 5 ohms. The machine harness has failed.
Repair: Repair the machine harness or replace the machine harness.
STOP
Test Step 3. CHECK THE OPERATION OF THE SWITCH
- The disconnect switch and the key start switch remain in the OFF position.
- The harness connectors for the ECM remain disconnected.
- Reconnect the harness connector for the switch.
- Ensure the parking brake switch is in the ON position. (Engage the parking brake).
- At the machine harness connector for the ECM, measure the resistance from connector contact 54 (wire C976-YL) to frame ground.
- At the machine harness connector for the ECM, measure the resistance from connector contact 55 (wire G764-PK) to frame ground.
Expected Result:
The resistance from connector contact 55 (wire G764-PK) to frame ground is less than 5 ohms, and the resistance from connector contact 54 (wire C976-YL) to frame ground is greater than 5 ohms.
Results:
- YES - The resistance from connector contact 55 (wire G764-PK) to frame ground is less than 5 ohms, and the resistance from connector contact 54 (wire C976-YL) to frame ground is greater than 5 ohms. The switch is operating correctly. Proceed to Test Step 4.
- NO - The resistance measurements do not differ for both contacts. The switch has failed.
Repair: Replace the switch.
STOP
Test Step 4. CHECK THE OPERATION OF THE SWITCH
- The disconnect switch and key start switch remain in the OFF position.
- The harness connectors for the ECM remain disconnected.
- Reconnect the harness connector for the switch.
- Ensure the parking brake switch is in the OFF position. (Disengage the parking brake).
- At the machine harness connector for the ECM, measure the resistance from connector contact 54 (wire C976-YL) and frame ground.
- At the machine harness connector for the ECM, measure the resistance from connector contact 55 (wire G764-PK) and frame ground.
Expected Result:
The resistance from connector contact 54 (wire C976-YL) to frame ground is less than 5 ohms, and the resistance from connector contact 55 (wire G764-PK) to frame ground is greater than 5 ohms.
Results:
- YES - The resistance from connector contact 54 (wire C976-YL) to frame ground is less than 5 ohms, and the resistance from connector contact 55 (wire G764-PK) to frame ground is greater than 5 ohms. The switch is operating correctly. Proceed to Test Step 5.
- NO - The resistance measurements do not differ for both contacts. The switch has failed.
Repair: Replace the switch.
STOP
Test Step 5. CHECK IF THE DIAGNOSTIC CODE REMAINS
- Inspect the contacts of the harness connectors and clean the harness connectors.
- Reconnect all the harness connectors.
- Turn the disconnect switch and the key start switch to the ON position.
- Operate the machine.
- Check the status of the CID 0070 FMI 03.
Expected Result:
The CID 0070 FMI 03 is active.
Results:
- YES - The CID 0070 FMI 03 is active. The diagnostic code has not been corrected. The ECM may have failed.
Repair: It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. If the cause of the diagnostic code is not found, replace the ECM. Refer to Troubleshooting, Testing and Adjusting, "Electronic Control Module (ECM) - Replace".
STOP
- NO - The CID 0070 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