Circuit/System Testing

WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION: Refer to SIR Caution .

Disable the inflatable restraint steering wheel module when performing this diagnostic. Refer to SIR Disabling and Enabling .

Ignition ON, with a scan tool observe the Cruise On/Off Switch parameter. Verify the parameter changes each time the switch is actuated
- If the parameter reads ON at all times replace the cruise control switch.
Ignition OFF, remove the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement .
Disconnect the harness connector at the cruise control switch assembly.
Ignition ON, test for 0 volts between the cruise control harness connector terminal 9 and ground.
- If voltage is present, test the circuit for a short to voltage.
Ignition OFF, disconnect the X3 connector at the BCM.
Test for less than 1.0 ohm between the cruise control harness connector terminal 9 and the BCM connector X3 terminal 22.
- If greater than the specified value, test the circuit for an open or high resistance.
Test for infinite resistance between the cruise control harness connector terminal 9 and ground.
- If resistance is measured, test the circuit for a short to ground.
If all circuits test normal, test the component. If the circuits and component tests are normal, replace the BCM.