P0581

DTC P0581

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.



DTC Descriptor
DTC P0581 00
- Cruise Control Multifunction Switch High Voltage




Diagnostic Fault Information






Circuit/System Description

The cruise control switch is an input to the engine control module (ECM). The ECM monitors the cruise control switch signal circuit in order to detect when a cruise control function switch has been requested. The ECM detects a predetermined voltage signal when a cruise control function switch is applied, with each switch having a different voltage value.


Conditions for Running the DTC

* The cruise switch is ON.
* The ignition is ON.



Conditions for Setting the DTC

* The ECM detects that the voltage on the cruise control switch signal circuit is greater than 3.5 volts.
* The above condition is present for greater than 1.5 seconds.
* The ECM/PCM runs this diagnostic every 0.05 second.



Action Taken When the DTC Sets

* The ECM/PCM stores the DTC information into memory when the diagnostic runs and fails.
* The malfunction indicator lamp (MIL) will not illuminate.
* The ECM records the operating conditions at the time the diagnostic fails. The ECM stores this information in the Failure Records.
* The cruise control system is disabled.



Conditions for Clearing the DTC

* The DTC becomes history when the fault is no longer present.
* A History DTC clears after 40 malfunction-free ignition cycles.



Diagnostic Aids

Ensure that the cruise control switches are not stuck or sticking in the applied position.


Reference Information
Schematic Reference

Cruise Control Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Cruise Control Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information


Circuit/System Verification

Ignition ON, Cruise Control Switch ON, verify that the Cruise Set/Coast Switch and Resume/Accel switch parameters read Inactive (OFF). The switch parameter should change to Active (ON) and back to Inactive (OFF) as the appropriate switch is pressed and released.


Circuit/System Testing

1. Ignition OFF, remove the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement (Service and Repair).
2. Disconnect the cruise control switch.
3. Ignition ON, verify that the scan tool Cruise Resume/Accel. Switch and Set/Coast switch parameters display Off or Inactive.

• If either of the scan tool parameters reads On, Active or Invalid, test the cruise control switch signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.

4. If all circuits test normal, replace the cruise control switch assembly.



Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Steering Wheel Control Switch Assembly Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for ECM replacement, setup, and programming