P0579

P0579-SPEED CONTROL SWITCH 1 PERFORMANCE





For a complete wiring diagram consult Diagrams/Electrical.


- When Monitored:
Continuously with the ignition on.

- Set Condition:
The Powertrain Control Module detects that the Speed Control Switch signal voltage received over the bus is not plausible.








Diagnostic Test


1. DTC IS ACTIVE

NOTE: Diagnose and repair any system voltage DTCs before proceeding with this test.


NOTE: Diagnose and repair any communication DTCs between the Steering Control Module (SCM) and the Powertrain Control Module before proceeding with this test.

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.

With a scan tool, select View DTCs.
Is the status Active for this DTC?

Yes


- Go to 2


No


- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure.Checking For An Intermittent DTC




2. SPEED CONTROL SWITCH
Turn the ignition off.
Replace the Speed Control Switch.
Turn the ignition on.
Move the Speed Control Switch to each position several times.
With the scan tool, Clear DTCs.
Move the Speed Control Switch to each position several times while monitoring related data on the scan tool.

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

With a scan tool, select View DTCs.
Is the status Active for this DTC?

Yes


- Go to 3


No


- Test Complete.




3. STEERING CONTROL MODULE (SCM)
Using the wiring diagram/schematic as a guide, inspect the related wiring and connectors.
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals.
Search for any Technical Service Bulletins that may apply.
Were any problems found?

Yes


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


No


- Replace the Steering Control Module (SCM).
- Perform the PCM Verification Test.Powertrain Verification Test