P0580

P0580-SPEED CONTROL SWITCH 1 CIRCUIT LOW





For a complete wiring diagram 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. Initial Inspection and Diagnostic Overview


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 (DIESEL). 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 (DIESEL). 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 (DIESEL). Powertrain Verification Test


No


- Go To 5



5. SCCM SHORTED TO GROUND
Turn the ignition off.
Disconnect the C1 SCCM 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 Steering Column Control Module.
- Perform POWERTRAIN VERIFICATION TEST (DIESEL). Powertrain Verification Test


No


- Go To 6



6. (V37) S/C SWITCH 1 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 (V37) S/C Switch 1 Signal circuit and ground (B-) at S/C ON/OFF Switch harness connector.
Is the resistance below 5.0 ohms?

Yes


- Repair the short to ground in the (V37) S/C Switch 2 Signal circuit.
- Perform POWERTRAIN VERIFICATION TEST (DIESEL). Powertrain Verification Test


No


- Go To 7



7. (V37) S/C SWITCH 1 SIGNAL CIRCUIT SHORTED TO THE (V937) S/C SWITCH RETURN CIRCUIT




Measure the resistance between the (V37) S/C Switch Signal circuit and the (V937) S/C Switch Return circuit at the ON/OFF switch harness connector.
Is the resistance below 5.0 ohms?

Yes


- Repair the short between the (V37) S/C Switch 1 Signal circuit and the (V937) S/C Switch Return circuit.
- Perform POWERTRAIN VERIFICATION TEST (DIESEL). Powertrain Verification Test


No


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