Operation CHARM: Car repair manuals for everyone.

P0581






P0581-SPEED CONTROL SWITCH 1 CIRCUIT HIGH







- When Monitored:
With the engine running and battery voltage greater than 10 Volts.

- Set Condition:
The Powertrain Control Module (PCM) detects that the sensor input voltage is above the maximum acceptable value.





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

1. DIAGNOSTIC TROUBLE CODE (DTC) IS ACTIVE
1. Start the engine and allow it to idle for at least 60 seconds.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.

NOTE: It may be necessary to test drive the vehicle and operate the speed control in order for this DTC to set.

2. With a scan tool, select View DTCs.

Is the status Active for this DTC?

Yes

- Go To 2

No

- Perform the CHECKING FOR AN INTERMITTENT DTC diagnostic procedure. Checking for an Intermittent DTC.

2. SPEED CONTROL SIGNAL 1 VOLTAGE





WARNING: Disconnect and isolate the battery negative (ground) cable before beginning steering wheel removal or installation. Allow the front airbag system capacitor to discharge for two minutes before removing the steering wheel or any front airbag system component. This will disable the front airbag system. Failure to disconnect the battery could result in accidental front airbag module deployment and possible personal injury.Do not place a non-deployed airbag face down on a hard surface as the airbag will propel into the air if accidentally deployed, and could result in serious or fatal injury.

1. Turn the ignition off.
2. Remove the Speed Control Switch.
3. Connect a jumper wire between the (V37) S/C Signal 1 circuit and the (V937) S/C Switch Ground circuit in the Speed Control Switch harness connector.
4. Turn the ignition on.
5. With a scan tool, read the (V37) S/C Signal 1 voltage.

NOTE: The (V37) S/C Signal 1 voltage should be below.2 of a Volt with the jumper wire in place.

Is the Speed Control Signal 1 voltage above 4.8 Volts with the Speed Control Switch connector disconnected and below.2 Volts with the jumper wire in place?

Yes

- Go To 6

No

- Go To 3

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




1. Turn the ignition off.
2. Disconnect the Powertrain Control Module (PCM) connector.
3. Turn the ignition on.
4. Measure the voltage of the (V37) S/C Signal 1 circuit in the Speed Control Switch harness connector.

Is there any voltage present?

Yes

- Repair the (V37) S/C Signal 1 circuit for a short to voltage.
- Perform the PCM Verification Test. PCM Verification Test.

No

- Go To 4

4. (V37) S/C SIGNAL 1 CIRCUIT OPEN OR HIGH RESISTANCE





NOTE: 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 the PCM Pinout Box 8815 to perform diagnosis.

1. Turn the ignition off.
2. Measure the resistance of the (V37) S/C Signal 1 circuit between the Speed Control Switch harness connector and the appropriate terminal of PCM Pinout Box 8815.

Is the resistance below 5.0 Ohms?

Yes

- Go To 5

No

- Repair the (V37) S/C Signal 1 circuit for an open circuit or high resistance.
- Perform the PCM Verification Test. PCM Verification Test.

5. (V937) S/C SWITCH GROUND CIRCUIT OPEN OR HIGH RESISTANCE





NOTE: 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 the PCM Pinout Box 8815 to perform diagnosis.

1. Measure the resistance of the (V937) S/C Switch Ground circuit between the Speed Control Switch harness connector and the appropriate terminal of PCM Pinout Box 8815.

Is the resistance below 5.0 Ohms?

Yes

- Go To 7

No

- Repair the (V937) S/C Switch Ground circuit for an open circuit or high resistance.
- Perform the PCM Verification Test. PCM Verification Test.

6. SPEED CONTROL SWITCH
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Speed Control Switch and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related connectors.
4. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
5. Look for the data to change or for the DTC to reset during the wiggle test.
6. Perform any Technical Service Bulletins that may apply.

Were any problems found?

Yes

- Repair as necessary.
- Perform the PCM Verification Test. PCM Verification Test.

No

- Replace the Speed Control Switch.
- Perform the PCM Verification Test. PCM Verification Test.

7. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Speed Control Switch and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related connectors.
4. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
5. Look for the data to change or for the DTC to reset during the wiggle test.
6. Perform any Technical Service Bulletins that may apply.

Were any problems found?

Yes

- Repair as necessary.
- Perform the PCM Verification Test. PCM Verification Test.

No

- Replace and program the Powertrain Control Module (PCM).
- Perform the PCM Verification Test. PCM Verification Test.