For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptors

DTC P0564: Cruise Control Multifunction Switch Circuit
DTC P0567: Cruise Control Resume Switch Circuit
DTC P0568 : Cruise Control Set Switch Circuit

### Diagnostic Fault Information

Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance
--- | --- | --- | --- | --- | ---
B+ | 1 | P0564 | 1 | -- | P0564
Cruise Control ON/OFF Switch Signal | 1 | P0564 | 1 | P0567 P0568 | P0564
Cruise Control Resume/Accel. Switch Signal | 1 | 1 | 1 | P0567 | --
Cruise Control Set/Coast Switch Signal | 1 | 1 | 1 | P0568 | --
1. Cruise Control Malfunction

### Circuit/System Description

The cruise control switch is an input to the body control module (BCM). The BCM monitors the cruise control on/off, set/coast, resume/accelerate and cancel switches via the cruise control switch signal circuit in order to detect when the driver has requested to perform a cruise control function. The BCM detects a specific voltage signal on the cruise control switch signal circuit when a switch is applied. The BCM sends a serial data message to the ECM indicating the status of the cruise control switches.

### Conditions for Running the DTC

• | The ignition is ON.

• | The cruise switch is ON.

### Conditions for Setting the DTC

#### P0564

The ECM detects an invalid voltage signal on the cruise control switch signal circuit for greater than 2 seconds.

#### P0567

The ECM detects that the Resume switch is applied for longer than 90 seconds.

#### P0568

The ECM detects that the Set/Coast switch is applied for longer than 90 seconds.

### Actions Taken When the DTC Sets

• | The malfunction indicator lamp (MIL) will not illuminate.

• | The cruise control system is disabled.

### Conditions for Clearing the DTC

• | 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

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Cruise Control Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

Engine ON, while rotating the steering wheel to both steering stops, observe the scan tool Cruise Control Switch parameter while pressing each of the cruise control switches. The parameter should toggle between On, Off, Resume, and Set as the applicable switch is pressed.

### Circuit/System Testing

#### Cruise Control Switch Circuit Malfunction

1. Ignition OFF, disconnect the harness connector at the steering wheel controls switch - left.
2. Ignition ON, test for B+ between the B+ circuit terminal 1 and ground.

⇒ | If less than the specified value, test the circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

3. Test for B+ between the B+ circuit terminal 1 and the signal circuit terminal 3.

⇒ | If less than the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.

4. Ignition OFF, disconnect the X1 harness connector at the BCM.
5. Test for infinite resistance between the signal circuit terminal 3 and ground.

⇒ | If less than the specified value, test the signal circuit for a short to ground.

6. If all circuits test normal, test or replace the steering wheel control switch - left.

### Component Testing

#### Steering Wheel Control Switch - Left

1. Disconnect the harness connector at the steering wheel controls switch - left.
2. Cruise control switch ON, measure the resistance between terminal 1 and terminal 3 while individually activating and holding each cruise control function switch and compare the resistance reading to the values in the table below.

⇒ | If not within the specified resistance range, replace the steering wheel controls switch - left.

Function Switch | Minimum Resistance Value | Maximum Resistance Value
--- | --- | ---
Off | O.L. | O.L.
On | 7.8k Ohms | 8.6k Ohms
- SET | 1.2k Ohms | 1.3k Ohms
+ RES | 2.7k Ohms | 3.0k Ohms
Cancel | 1.4k Ohms | 1.6k Ohms

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Steering Wheel Control Switch Assembly Replacement

• | Control Module References for BCM replacement, setup, and programming