P0581

P0581-SPEED CONTROL SWITCH 1 CIRCUIT HIGH





For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.

- When Monitored:
Key on or Engine running.

- Set Condition:
Speed Control MUX switch above 11.5 Volts for five seconds.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. SCAN TOOL SHOWS SPEED CONTROL SWITCH ON/OFF
1. Turn the ignition on.
2. With the scan tool in Inputs/Outputs, read the Speed Control inputs state in ECM.
3. While monitoring the scan tool, push the Speed Control On/Off Switch several times, then leave it on.

Did the scan tool show Speed Control Switch off and on?

Yes

- Perform the INTERMITTENT DTC diagnostic procedure.Intermittent Condition Test

No

- Go To 2

2. S/C WIRING HARNESS OBSERVABLE PROBLEM
1. Turn the ignition off.
2. Using the Schematics as a guide, inspect the Wiring and Connectors.

Were any problems found?

Yes

- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST (DIESEL). Powertrain Verification Test.

No

- Go To 3

3. CLOCKSPRING




1. Disconnect the C1 and C3 Clockspring harness connectors.

NOTE: Check connectors - Clean/repair as necessary.

2. Measure the resistance of the (V937) S/C Switch Return circuit between the C1 and C3 Clockspring harness connectors.





3. Measure the resistance of the (V37) S/C Switch 1 Signal circuit between the C1 and C3 harness connectors.

Was the resistance above 5.0 Ohms for either circuit?

Yes

- Replace the Clockspring.
- Perform the POWERTRAIN VERIFICATION TEST (DIESEL). Powertrain Verification Test.

No

- Go To 4

4. SPEED CONTROL ON/OFF SWITCH
1. Disconnect the Speed Control On/Off Switch 2-way harness connector only.

NOTE: Check connectors - Clean/repair as necessary.

2. Measure the resistance across the S/C On/Off Switch.

Is the resistance between 20.3K and 20.7K Ohms?

Yes

- Go To 5

No

- Replace the On/Off Switch.
- Perform POWERTRAIN VERIFICATION TEST (DIESEL). Powertrain Verification Test.

5. (V37) S/C SWITCH 1 SIGNAL CIRCUIT SHORTED TO VOLTAGE




1. Turn the ignition on.
2. Measure the voltage of the (V37) S/C Switch 1 Signal circuit at the On/Off Switch connector.

Is the voltage above 6.0 Volts?

Yes

- Repair the (V37) V37 Switch 1 Signal circuit for a short to voltage.
- Perform the POWERTRAIN VERIFICATION TEST (DIESEL). Powertrain Verification Test.

No

- Go To 6

6. (V37) S/C SWITCH 1 SIGNAL CIRCUIT OPEN ECM TO CLOCKSPRING
1. Turn the ignition off.
2. Disconnect the ECM harness connector.

NOTE: Check connectors - Clean/repair as necessary.

3. Measure the resistance of the (V37) S/C Switch 1 Signal circuit between the ECM connector and the C1 Clockspring harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 7

No

- Repair open in the (V37) S/C Switch 1 Signal circuit between the ECM and Clockspring.
- Perform the POWERTRAIN VERIFICATION TEST (DIESEL). Powertrain Verification Test.

7. (V37) S/C SWITCH 1 SIGNAL CIRCUIT OPEN BETWEEN THE CLOCKSPRING AND S/C SWITCH




1. Measure the resistance of the (V37) S/C Switch 1 Signal circuit from the C3 Clockspring harness connector to the S/C switch harness connectors.

Is the resistance below 5.0 Ohms?

Yes

- Go To 8

No

- Repair the open in the (V37) S/C Switch 1 Signal circuit between the Clockspring and S/C Switches.
- Perform the POWERTRAIN VERIFICATION TEST (DIESEL). Powertrain Verification Test.

8. (V937) S/C SWITCH RETURN CIRCUIT OPEN CLOCKSPRING TO S/C SWITCH




1. Measure the resistance of the (V937) S/C Switch Return circuit between the S/C Switch harness connectors to the Clockspring harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 9

No

- Repair open in the (V937) S/C Switch Return circuit between the Clockspring and the S/C Switches.
- Perform the POWERTRAIN VERIFICATION TEST (DIESEL). Powertrain Verification Test.

9. (V937) S/C SWITCH RETURN CIRCUIT OPEN BETWEEN THE ECM AND CLOCKSPRING
1. Measure the resistance of the (V937) S/C Switch Return circuit between the ECM harness connector to the C1 Clockspring harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Replace and program the ECM.
- Perform the POWERTRAIN VERIFICATION TEST (DIESEL). Powertrain Verification Test.

No

- Repair open in the (V937) S/C Switch Return circuit from between the ECM and Clockspring.
- Perform the POWERTRAIN VERIFICATION TEST (DIESEL). Powertrain Verification Test.