P0581

P0581-SPEED CONTROL SWITCH #1 HIGH

For a complete wiring diagram Consult Diagrams/Electrical

- When Monitored:
With the ignition key on. Battery voltage above 10 volts.

- Set Condition:
The PCM detects an open or short to voltage in the Speed Control Switch Signal circuit. One Trip Fault.





Diagnostic Test

1. SPEED CONTROL SWITCH VOLTAGE HIGH
Ignition on, engine not running.
With the scan tool in Sensors, read the S/C Switch Volts.
Is the Speed Control voltage above 4.8 volt?

Yes

- Go To2

No

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure.Intermittent Condition
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

2. SPEED CONTROL SWITCH




Turn the ignition off.
Remove the Speed Control Switch.
With the scan tool in Sensors, monitor the S/C Switch Volts.
With the S/C Switch disconnected, the S/C Switch Volts should equal 5.0 volts.
Connect a jumper wire between the (V71) S/C Switch No. 1 signal circuit and the (V937/K914) S/C Switch Return circuit in the S/C Switch harness connector.
Turn the ignition on.
With the jumper wire in place, the S/C Switch Volts should equal 0 volts.
Does the S/C Switch Volts display on the scan tool as described?

Yes

- Go To3

No

- Replace the Speed Control Switch.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

3. (V71) S/C SWITCH NO. 1 SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE




Turn the ignition off.
Disconnect the Speed Control Switch harness connector.
Disconnect the PCM harness connector.
Measure the voltage of the (V71) S/C Switch No. 1 signal circuit in the Speed Control Switch harness connector.
Is the is the voltage above 5.0 volts?

Yes

- Repair the (V71) S/C Switch No. 1 signal circuit for a short to battery voltage.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To4

4. (V937/K914) S/C SWITCH RETURN CIRCUIT OPEN




CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.

Measure the resistance of the (V937/K914) S/C Switch Return circuit from the Speed Control Switch harness connector to the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?

Yes

- Before continuing, check the PCM harness connector terminals for corrosion, damage or terminal push out. Repair as necessary. Replace and program the Powertrain Control Module.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Repair the open (V937/K914) S/C Switch Return circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test