The ABS electronic control module (which may be referred to as an EBCM "Electronic Brake Control Module") is a microprocessor that functions like the engine control computer. To troubleshoot the ABS system you may need to check the codes stored in the EBCM. You must short two pins on the ALDL connector located under the dash on the drivers side.

Checking ABS codes is not done with a normal scanner or through the Reatta diagnostics screen.

How to check EBCM codes:

• With the key off remove the ALDL cover
• Using a piece of wire or a small paper clip, jumper the following terminals in the ALDL connector:
  • 1988 model - terminals A&G
  • 1989 and 1990 model - terminals A&H
  • 1991 model?

Turn the key on. Yellow ABS light will flash. Count the flashes. The light will flash a number of times, pause, then flash some more. Write down the first codes, then while leaving the key on, remove the jumper, then put it back. If there is a second code it will flash.

Example:
First code with key on:
Flash + Flash
Pause
Flash + Flash
Pause
Then ABS light stays on solid

This would be a code 22 (Flash, Flash + Flash, Flash =22)

Then take off the jumper while the key is on and re-insert:
Flash
Pause
Flash + Flash + Flash
Pause
Then ABS light stays on solid.

This would be a code 13 (Flash + Flash, Flash, Flash =13)

Repeat removing and replacing the jumper until the yellow light stays on steady. This will give you all the codes stored in the EBCM.

Refer to the Field Service Manual (FSM) for interpreting the codes and troubleshooting the ABS system.

This information courtesy of Padgett.

  Click here for a chart of ABS codes.