The cruise control switch is an input to the engine control module (ECM) / powertrain control module (PCM). The ECM (5.3L) / PCM (3.8L) monitors the cruise control set/coast and resume/accelerate switch signal circuit in order to detect when a cruise control function has been requested. The ECM detects a specific voltage signal on the cruise control set/coast and resume/accelerate switch signal circuit when a cruise control function switch is activated, with each switch having a different predetermined voltage value.

Important: Repair any brake system related symptoms and DTCs before performing this diagnostic.

In order to avoid misdiagnosis, inspect for the following:

Schematic Reference

Cruise Control Schematics

Connector End View Reference

Electrical Information Reference

Scan Tool Reference

Scan Tool Data List

Important: Repair any brake system related symptoms and DTCs before performing this diagnostic.

Ignition ON, cruise on/off switch ON, 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 in the ECM/PCM. Verify that each cruise control switch activated and that each displayed switch position parameters match accordingly with each depressed switch, as the steering wheel is turned.

1. Ignition OFF, remove the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement .
2. Disconnect the harness connector C4 of the multifunction turn signal lever.
3. Ignition ON, measure for 10 volts or greater at the multifunction turn signal lever control supply voltage circuit terminal 1.

⇒	If less than the specified value, check for an open/high resistance or a short to ground on the multifunction turn signal lever control supply voltage circuit.

4. Ignition OFF, disconnect the harness connector C1 at the ECM/PCM.
5. Ignition OFF, test for 1.0 ohm of resistance or less between the multifunction turn signal lever terminal 5 and ECM terminal 29 (PCM terminal 44).

⇒	If greater than the specified range, test the cruise control switch signal circuit for an open/high resistance.

6. Ignition OFF, test for infinite resistance between the multifunction turn signal lever terminal 5 and ground.

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

7. Ignition ON, test for 0 volts between the multifunction turn signal lever terminal 5 and ground.

⇒	If greater than the specified value, test the cruise control switch signal circuit for a short to voltage.

8. If all circuits test normal, test the component. If the component tests normal, replace the PCM/ECM.

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, remove the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement .
2. Disconnect the harness connector C4 at the multifunction turn signal lever.
3. Cruise control switch ON, measure the resistance between terminals 1 and 5 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/cruise, and the resume/accel.

⇒	If any of the resistance measurements for the OFF, ON, set/cruise, resume/accel are not within the listed resistance values, replace the multifunction turn signal lever.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.