GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2000 🢒 Seville 🢒 Body and Accessories 🢒 Horns 🢒 Diagnostic System Check - Horns

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

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

    2.

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

    4.

  4. At this point you have determined all DTCs applicable to the Horns system. Refer to Symptoms for further Horns diagnosis. Any other codes displayed from the listed modules do not apply to Horns and should be diagnosed in their applicable section.

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 Dash Integration Module (DIM).

Does the scan tool communicate with the DIM?

Go to Step 3

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

3

Select the DIM display DTCs function on the scan tool.

Does the scan tool display any DTCs?

Go to Step 4

Go to Symptoms

4

Does the scan tool display DTCs that begin with "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 DTC B1007 or B1009?

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

Go to Step 6

6

Does the scan tool display DTC B1327 or B1328?

Go to Diagnostic Trouble Code (DTC) List/Type in Engine Electrical

Go to Symptoms