GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2004 🢒 GTO 🢒 Engine 🢒 Engine Cooling 🢒 Diagnostic System Check - Engine Cooling

Test Description

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

  1. Lack of communication may be due to a partial or total malfunction of the class 2 serial data circuit or due to a partial or total malfunction of the UART data circuit. The specified procedure will determine the particular condition.

    2.

  2. The symptom list 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. The specified procedure will compile all the available information before tests are performed.

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 following modules:
    3. • Powertrain control module (PCM)
    • Powertrain interface module (PIM)
    • Body control module (BCM)
    • Instrument panel cluster (IPC)

Does the scan tool communicate with all of the modules?

Go to Step 3

Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications

3

  1. Select the Display DTCs function for each module.
  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 4

Go to Symptoms - Engine Cooling

4

Does the scan tool display any DTCs which begin with a "U"?

Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications

Go to Step 5

5

Does the scan tool display any DTCs which begin with a "B"?

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

Go to Diagnostic Trouble Code (DTC) List