The cruise control switch is an input to the engine control module (ECM), while the cruise cancel switch is an input to the body control module (BCM). The ECM monitors the cruise control on/off, set/coast, and the resume/accelerate switch signal circuits 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.

The BCM monitors the cruise cancel switch in order to detect when the cancel switch has been activated. The BCM sends a class 2 message to the ECM regarding the status of the cruise cancel switch.

In order to avoid misdiagnosis, inspect for the following:

Schematic Reference

Connector End View Reference

Description and Operation

Cruise Control Description and Operation

Electrical Information Reference

Scan Tool Reference

Scan Tool Data List

1. Verify that DTC P0573 is not set in the ECM.

⇒	If that DTC is set as current or history, go to Diagnostic Trouble Code (DTC) List - Vehicle .

2. Rotate the steering wheel to both steering stops while activating each cruise control switch separately. With a scan tool, observe all cruise control switch parameters. Ensure that each cruise control switch activated and that each displayed switch position parameters match as the steering wheel is turned.

⇒	If the parameters do not match with each depressed switch accordingly, go to Circuit/System Testing.

1. Ignition OFF, disconnect the harness connector C3 at the BCM.
2. Ignition ON, verify that a test lamp does not illuminate between the cruise control cancel signal circuit terminal 6 and ground.

⇒	If the test lamp illuminates, test the cruise control cancel signal circuit for a short to voltage. If the circuit tests normal, test or replace the cruise control switch assembly.

3. Ignition ON, cruise control switch ON. While depressing the CANCEL switch, measure for 10 volts or greater between the cruise control cancel signal circuit terminal 6 and ground.

⇒	If less than 10 volts, test the cruise control cancel signal circuit and the cruise control supply voltage circuit for an open/high resistance, or a short to ground. If the circuits test normal, test or replace the cruise control switch assembly.

4. Ignition OFF, connect the harness connector C3 at the BCM. Disconnect the harness connector at the cruise control switch assembly.
5. Ignition ON, verify that a test lamp illuminates between B+ and the cruise control cancel signal circuit terminal 3.

⇒	If the test lamp does not illuminate, test the cruise control cancel signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM.

6. Ignition OFF, test for an open/high resistance, a short to ground, or a short to voltage in the cruise control switch signal circuit.

⇒	If the circuit tests normal, test the component. If the circuits and the component tests are normal, replace the ECM.

Important: The cruise control switch must be ON in order to properly measure the resistance of the - SET, the + RES, and the Cancel switches.

1. Ignition OFF, remove the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement .
2. Disconnect the harness connector at the cruise control switch.
3. Cruise control switch ON, measure the resistance between terminals 2 and 1 at 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 on the schematic for the ON/OFF, - SET, and the + RES.

⇒	If any of the resistance measurements for the OFF, ON, - SET, and + RES are not within the listed resistance values, replace the cruise control switch assembly.

4. Cruise control switch ON, measure the resistance between terminals 2 and 3 at the cruise control switch side of the connector. Activate and deactivate the cancel switch.

⇒	If the resistance is not within the table value when activated, replace the cruise control switch assembly.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.