The numbers below refer to the step numbers on the diagnostic table.
Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.
This step is checking for adequate system voltage. If the ignition voltage is low, RAP will be disabled in order to conserve power.
Step | Action | Yes | No |
---|---|---|---|
1 | Install a scan tool. Does the scan tool power up? | Go to Step 2 | Go to Scan Tool Does Not Power Up in Data Link Communications |
Does the scan tool communicate with the BCM? | Go to Step 3 | Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications | |
3 |
Important: The engine may start during the following step. Turn OFF the engine as soon as you have observed the Crank power mode.
Does the Class 2 Power Mode parameter reading match the ignition switch position for all the selected positions? | Go to Step 4 | Go to Power Mode Mismatch in Body Control System |
Observe Ignition Voltage in the BCM data list with a scan tool. Is Ignition Voltage at least 12 volts? | Go to Symptoms - Engine Electrical in Engine Electrical |