Did you perform the Battery Inspection/Test?

Go to Step 2

Go to Battery Inspection/Test

Install a scan tool.

Does the scan tool power up?

Go to Step 4

Go to Scan Tool Does Not Power Up

Important: The engine may start during the following step. Turn OFF the engine as soon as you have observed the Crank power mode.

1. Access the Class 2 Power Mode in the Diagnostic Circuit Check on the scan tool.
2. Rotate the ignition switch through all positions while observing the ignition switch power mode parameter.

Does the ignition switch parameter reading match the ignition switch position for all switch positions?

Go to Step 4

Go to Power Mode Mismatch in Body Control System

4

1. Turn ON the ignition, with the engine OFF.
2. Attempt to communicate with each module on the class 2 serial data circuit.

If using a Tech 2, obtain this information using the Class 2 Message Monitor feature.

Does the scan tool communicate with any module on the class 2 serial data circuit?

Go to Step 5

Go to Scan Tool Does Not Communicate with Class 2 Device

5

1. Select the Display DTCs function for each module.

If using a Tech 2, use the Class 2 DTC Check feature in order to determine which modules have DTCs set.

2. Record all of the displayed DTCs the DTC status and the module which set the DTC.

Does the scan tool display any DTCs?

Go to Step 6

Go to Symptoms - Engine Electrical

6

Does the scan tool display any DTC beginning with "U"?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 7

Does the scan tool display any DTC beginning with "P"?

Go to Powertrain DTC list in Engine Controls

Go to Step 8

Does the scan tool display any DTC beginning with "B"?

Go to Diagnostic Trouble Code (DTC) List

Go to Diagnostic Trouble Code (DTC) List