P0581
P0581-HIGH VOLTAGE DETECTED AT THE SPEED CONTROL SWITCH
For complete wiring diagrams refer to Diagrams/Electrical.
- When Monitored:
Key on or Engine running.
- Set Condition:
Speed Control MUX switch above 11.5 volts for 5 seconds.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.
Diagnostic Test
1. SCAN TOOL SHOWS SPEED CONTROL SWITCH ON/OFF
Turn the ignition on.
With the scan tool in Inputs/Outputs, read the Speed Control inputs state in ECM.
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
- Go To 2
No
- Test Complete.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
2. S/C WIRING HARNESS OBSERVABLE PROBLEM
Turn the ignition off.
Using the Schematics as a guide, inspect the Wiring and Connectors.
Were any problems found?
Yes
- Repair as necessary.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
No
- Go To 3
3. CLOCKSPRING SIGNAL/GROUND CIRCUIT OPEN
Disconnect the upper and lower clockspring harness connectors.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance of the sensor ground circuit between the upper and lower clockspring harness connectors.
Measure the resistance of the speed control switch signal circuit between the upper and lower clockspring harness connectors.
Was the resistance above 5.0 ohms for either circuit?
Yes
- Replace the clockspring.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
No
- Go To 4
4. SPEED CONTROL ON/OFF SWITCH
Disconnect the Speed Control On/Off Switch 2-way harness connector only.
NOTE: Check connectors - Clean/repair as necessary.
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. Powertrain Verification Test
5. S/C SWITCH SIGNAL CKT SHORTED TO VOLTAGE
Turn the ignition on.
Measure the voltage of the S/C Switch Signal Circuit at the On/Off Switch 2-way connector.
Is the voltage above 6.0 volts?
Yes
- Repair the Speed Control Switch Signal Circuit for a short to voltage.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
No
- Go To 6
6. S/C SWITCH SIGNAL CIRCUIT OPEN ECM TO CLOCK SPRING
Turn the ignition off.
Disconnect the ECM harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance of the S/C Switch Signal Circuit between the ECM connector and the Clockspring Connector.
Is the resistance below 5.0 ohms?
Yes
- Go To 7
No
- Repair open Speed Control Switch Signal Circuit ECM to Clockspring.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
7. S/C SWITCH SIGNAL CIRCUIT OPEN CLOCKSPRING TO S/C SWITCH
Measure the resistance of the S/C Switch Signal Circuit from the clockspring harness connector to the On/Off switch harness connector.
Is the resistance below 5.0 ohms?
Yes
- Go To 8
No
- Repair the open Speed Control Switch Signal Circuit Clockspring to S/C switch.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
8. S/C SWITCH GROUND CIRCUIT OPEN CLOCKSPRING TO S/C SWITCH
Measure the resistance of the S/C Switch Sensor Ground Circuit between the On/Off Switch 2-way harness connector to the clockspring harness connector.
Is the resistance below 5.0 ohms?
Yes
- Go To 9
No
- Repair open ground circuit from clockspring to S/C switch.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
9. S/C SWITCH GROUND CIRCUIT OPEN ECM TO CLOCKSPRING
Measure the resistance of the S/C Switch Sensor Ground Circuit between the ECM harness connector to the clockspring harness connector.
Is the resistance below 5.0 ohms?
Yes
- Replace and program the ECM.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
No
- Repair open ground circuit from ECM to clockspring.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test