P0564
DTC P0564
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 P0564
- Cruise Control Multifunction Switch Circuit
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 activated. 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 an invalid voltage signal on the cruise control switch signal circuit.
* The above condition is present for greater than 2 seconds.
* The ECM runs this diagnostic every 0.05 second.
Action Taken When the DTC Sets
* 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
* A current DTC will clear when the condition responsible for setting the DTC no longer exists.
* A history DTC will clear after 40 malfunction-free ignition cycles have occurred.
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 ON, at the back of the column harness connector X204 terminal A8, measure for 10 volts or greater on the cruise control supply voltage circuit.
• If less than the specified value, test the cruise control supply voltage circuit for an open/high resistance or a short to ground.
2. Ignition OFF, disconnect column harness connector X204.
3. Ignition ON, verify a test lamp illuminates between B+ and the cruise control switch signal circuit connector X204 terminal B8 on the body side of the harness.
• If the test lamp does not illuminate, test the cruise control switch signal circuit for an open/high resistance or a short to voltage. If the circuit tests normal, replace the ECM.
4. Ignition OFF, disconnect the harness connector X1 at the ECM.
5. Verify that a test lamp does not illuminate between B+ and the cruise control switch signal circuit connector X204 terminal B8 on the body side of the harness.
• If the test lamp illuminates, test the cruise control switch signal circuit for a short to ground.
6. If all circuits test normal, test the component. If the circuits and the component tests are normal, replace the ECM.
Component Testing
Important: The cruise control switch must be ON in order to properly measure the resistance of the set/cruise and the resume/accel switches.
1. Ignition OFF, disconnect the steering column harness connector X204.
2. Cruise control switch ON, measure the resistance between terminals A8 and B8 on the cruise control switch side of the connector. Individually activate and hold each cruise control function switch and compare the resistance reading to the values in the table for the appropriate switch.
• If any resistance measurements for any of the switches are not within the listed resistance values, replace the cruise control switch assembly.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Turn Signal Multifunction Switch Replacement (Turn Signal Multifunction Switch Replacement)
* Control Module References (Programming and Relearning) for ECM replacement, setup, and programming