Component Testing
WARNING: This page is about a different car, the 2008 Buick LaCrosse and 2008 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.
Verify that there is near battery voltage on the ignition 1 voltage circuit at the TCM.
If the voltage is not near the specified value, repair the short to ground, open, or high resistance in the ignition 1 voltage circuit.