GM Service Manual Online
For 1990-2009 cars
Makes 🢒 Saturn 🢒 2004 🢒 ION 🢒 Body 🢒 Stationary Windows 🢒 Diagnostic System Check - Defogger

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. Lack of communication may be due to a partial malfunction of the serial bus communication data circuit.

  2. The symptom table will determine the correct diagnostic procedure to use.

    3.

  3. The presence of DTCs which begin with "U" indicate some other module is not communicating.

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

2

  1. Turn ON the ignition, with the engine OFF.
  2. Attempt to establish communication with the body control module (BCM).

Does the scan tool communicate with the module?

Go to Step 3

Go to Data Link References 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.

  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

Select the display DTCs function on the scan tool for the body control module (BCM).

Does the scan tool display any DTCs?

Go to Step 5

Go to Symptoms - Stationary Windows

5

Does the scan tool display DTCs that begin with "U"?

Go to Diagnostic Trouble Code (DTC) List in Data Link Communication

Go to Step 6

6

Does the scan tool display DTC B0285?

Go to Diagnostic Trouble Code (DTC) List

Go to Diagnostic Trouble Code (DTC) List in Body Control System