Operation CHARM: Car repair manuals for everyone.

P0580






P0580-LOW VOLTAGE DETECTED AT THE SPEED CONTROL SWITCH





For complete wiring diagrams refer to Diagrams/Electrical.


- When Monitored:

While the ignition is on

- Set Condition:

Speed control MUX switch below 1.0 volts for 5 seconds.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Diagnostic Test


1. S/C SWITCH VOLTAGE BELOW 1.0 VOLT

Turn the ignition on.

With the scan tool, read the S/C Switch volts status in the ECM.

Is the S/C Switch voltage below 1.0 volt?

Yes

- Go To 3

No

- Go To 2

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. S/C SWITCH (ON/OFF)

Turn the ignition off.

Disconnect the S/C ON/OFF Switch harness connector.


NOTE: Check connectors - Clean/repair as necessary.

Turn the ignition on.

With the scan tool in Sensors, read the S/C Switch volts in the ECM.

Did the S/C Switch volts change to 5.0 volts?

Yes

- Replace the S/C ON/OFF Switch.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 4

4. S/C SWITCH (RESUME/ACCEL)

Turn the ignition off.

Disconnect the S/C RESUME/ACCEL Switch harness connector.


NOTE: Check connectors - Clean/repair as necessary.

Ignition on, engine not running.

With the scan tool in Sensors, read the S/C Switch volts in the ECM.

Did the S/C Switch volts go above 4.0 volts?

Yes

- Replace the Resume/Accel Switch.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 5

5. CLOCKSPRING SHORTED TO GROUND





Turn the ignition off.

Disconnect the clockspring 6-way harness connector (instrument panel wiring side).

Turn the ignition on.

With the scan tool in Sensors, read the S/C Switch volts in the ECM.

Did the S/C Switch volts change to 5.0 volts?

Yes

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

No

- Go To 6

6. S/C SWITCH SIGNAL CIRCUIT SHORTED TO GROUND





Turn the ignition off.

Disconnect the S/C ON/OFF Switch harness connector.

Disconnect the ECM harness connectors.


NOTE: Check connectors - Clean/repair as necessary.

Measure the resistance between the S/C Switch Signal circuit and ground (B-) at S/C ON/OFF Switch harness connector.

Is the resistance below 5.0 ohms?

Yes

- Repair S/C Switch Signal Circuit for a short to ground.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 7

7. S/C SIGNAL CIRCUIT SHORTED TO SENSOR GROUND





Measure the resistance between the S/C Signal Circuit and the Sensor Ground Circuit at the ON/OFF switch harness connector.

Is the resistance below 5.0 ohms?

Yes

- Repair S/C Signal Circuit shorted to Sensor Ground.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

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