GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 1999 🢒 Grand Am 🢒 Brakes 🢒 Antilock Brake System 🢒 Diagnostic System Check - Data Link Communications

Test Description

  1. This step is to determine if the scan tool is operating properly.

    2.

  2. This step is to check the Class 2 communications system for any DTC's that may be set.

    3.

  3. This step is to determine if the scan tool can communicate with the UART Data Line, specifically within the Supplemental Inflatable Restraint System.

    4.

  4. This step determines if the Serial Data communication between the EBCM and the scan tool can be accomplished.

Step

Action

Normal Result(s)

Abnormal Result(s)*

1

Connect the Scan Tool to the data link connector (DLC).

The Scan Tool main menu appears on the scan tool.
    • Blank Screen
    • No power to the scan tool

Refer to Scan Tool Inoperative

2

Select Diagnostics Circuit Check, Class 2 DTC Check from the scan tools menu.

No DTC's found.

The module(s) listed will have DTC's present.

Refer to Diagnostic Trouble Code (DTC) List/Type in Body Control Systems.

3

  1. Select Body Diagnostics from the scan tools menu.
  2. Select SIR UART Data Line information.
  3. Access DTC's using the scan tool.

No DTC's found.
    • The SIR system will have DTC's present.
    • No communication with the UART data line.

Refer to SIR Diagnostic System Check

4

  1. Establish communication with the Electronic Brake Control Module (EBCM)
  2. Access DTC's using the scan tool.

No DTC's found.

The ABS system will have DTC's present.

Refer to Diagnostic System Check - ABS

* Refer to the appropriate symptom diagnostic table for the applicable abnormal result.