Conditions Which Generate This Code:
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| Illustration 1 | g00984943 |
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Schematic of the Rocker Switch for the Parking Brake | |
| CID 0070 BRAKE SWITCH OF THE TRANSMISSION CONTROL | ||||
| ECM
Contact |
Switch Contact | Wire
Number |
Switch Status | |
| The Switch is not Activated.
(The switch is not in the park position.) |
Activated
(The switch is in the park position.) |
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| D-22, "N/O"(1) | N/O | C976-YL(Yellow) | O(2) | R(3) |
| D-21, "N/C"(4) | N/C | E417-OR(Orange) | R | O |
| D-15, "Return" | COM | G939-PK(Pink) | R | R |
| (1) | "N/O" means Normally Open. |
| (2) | "O" means open. (The circuit is open.) |
| (3) | "R" means return. (There is less than 5 ohms resistance to the return circuit or ground.) |
| (4) | "N/C" means Normally Closed. |
This switch has two inputs to the ECM. The two inputs are N/O and N/C. During normal operation, one of the inputs is open. The other input is grounded. Table 1 shows the status of each circuit for the two positions of the switch. When a circuit is measured with a voltmeter, an open circuit will measure approximately 5 DCV and a closed circuit will measure approximately 0 DCV.
An FMI 03 diagnostic code is recorded when the status of both the inputs are open.
The possible causes of this diagnostic code are listed below:
- The return circuit (wire G939-PK(Pink)) is open.
- The "N/O" signal circuit (wire C976-YL(Yellow)) is open.
- The "N/C" signal circuit (wire E417-OR(Orange)) is open.
- The brake switch of the transmission control has failed.
- The ECM has failed. This is unlikely.
Note: Ensure that the CID 0070 FMI 03 is on hold and that the diagnostic code indicator shows "SERV CODE". The diagnostic code will only be present when the speed/direction control lever is in the position which causes both inputs (N/O and N/C) to be open at the same time. If "SERV CODE" is NOT showing, move the speed/direction control lever to the position that causes "SERV CODE" to show.
Test Step 1. CHECK THE N/C CIRCUIT FOR PROPER OPERATION.
- Turn the key start switch to the OFF position.
- Disconnect the machine harness from the ECM.
- At the machine harness connector D, measure the resistance from contact D-21 (wire E417-OR(Orange)) to contact D-15 (wire G939-PK(Pink)).
Expected Result:
When the lever is out of the PARK position, there should be less than 5 ohms.
Results:
- OK - The measurement is within an acceptable range. Proceed to test step 3.
- NOT OK - The switch or the machine harness has failed. Proceed to test step 2.
Test Step 2. CHECK THE "N/C" CIRCUIT OF THE SWITCH.
This check determines whether the switch or the machine harness has failed.
- Disconnect wire C976-YL(Yellow) and wire E417-OR(Orange) from the parking brake switch.
- At the switch, measure the resistance between the "N/C" terminal and the common terminal.
Expected Result:
With the lever out of the PARK position, there should be less than 5 ohms of resistance.
Results:
- OK - The resistance is within an acceptable range. The machine harness has failed.
Repair: Either the "N/C" circuit (wire E417-OR(Orange)) or the return circuit (wire G939-PK(Pink)) is open in the machine harness. Repair the machine harness or replace the machine harness.
STOP
- NOT OK - The resistance is not within an acceptable range. The switch has failed.
Repair: Replace the parking brake switch. Verify that the new switch corrects the diagnostic code.
STOP
Test Step 3. CHECK THE N/O CIRCUIT FOR PROPER OPERATION.
- At machine harness connector D, measure the resistance from contact D-22 (wire C976-YL(Yellow)) to contact D-15 (wire G939-PK(Pink)).
Expected Result:
With the speed/direction control lever in the PARK position, there should be less than 5 ohms of resistance.
Results:
- OK - The resistance is within an acceptable range. Proceed to test step 5.
- NOT OK - The resistance is not within an acceptable range. The switch or the machine harness has failed. Proceed to test step 4.
Test Step 4. CHECK THE "N/O" CIRCUIT OF SWITCH.
This check determines whether the switch or the machine harness has failed.
- Disconnect the wires C976-YL(Yellow) and E417-OR(Orange) from the parking brake switch.
- At the switch, measure the resistance between the "N/O" terminal and the common terminal.
Expected Result:
With the speed/direction control lever in the PARK position, there should be less than 5 ohms of resistance.
Results:
- OK - The machine harness has failed.
Repair: Either the "N/O" circuit (wire C976-YL(Yellow)) or the return circuit (wire G939-PK(Pink)) is open in the machine harness. Repair the machine harness or replace the machine harness.
STOP
- NOT OK - The resistance is not within an acceptable range. The switch has failed.
Repair: Replace the parking brake switch. Verify that the new switch corrects the diagnostic code.
STOP
Test Step 5. CHECK IF THE DIAGNOSTIC CODE REMAINS.
- Clean the contacts of the harness connectors.
- Reconnect all harness connections.
- Turn the key start switch to the ON position.
- Enter the service mode of the AVSpare Monitoring System and clear all inactive diagnostic codes.
- Operate the machine.
- Determine if CID 0070 FMI 03 is present.
Expected Result:
The CID 0070 FMI 03 is NOT present. "SERV CODE" is NOT showing.
Results:
- YES - The diagnostic code is NOT present. The problem does not exist at this time. The initial problem 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
- NO - The diagnostic code has not been corrected. It is unlikely that the ECM has failed.
Repair: Exit this procedure and perform this procedure again. If the diagnostic code is still present, replace the ECM. Refer to Testing and Adjusting, "Electronic Control Module (ECM) - Replace".
STOP