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Home >> Cadillac >> 2002 >> Escalade EXT >> Repair and Diagnosis >> External Pages >> Different car >> Section 986 (Antilock Brake System And Traction Control System) >> Diagnostic Information and Procedures >> Diagnostic System Check - ABS >> Circuit Description
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Circuit Description

WARNING: This page is about a different car, the 2004 Pontiac Aztek and 2004 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.

The ABS Diagnostic System Check is an organized approach to identify problems associated with the EBCM. This check must be the starting point for any EBCM complaint, and will direct you to the next logical step in diagnosing the complaint. The EBCM is a very reliable component and is not likely the cause of the malfunction. Most system complaints are linked to faulty wiring, connectors, and occasionally to components. Understanding the ABS system and using the tables correctly will reduce diagnostic time and prevent unnecessary parts replacement.

Diagnostic System Check - ABS

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 control modules:
    • Body control module (BCM)
    • Electronic brake control module (EBCM)
    • Instrument panel module (IPC)
    • Powertrain control module (PCM)
Does the scan tool communicate with all control modules?
Go to Step 3  Go to Scan Tool Does Not Communicate with Class 2 Device In Data Link Communications
3 Select the display DTCs function on the scan tool for the following control modules:
  • Body control module (BCM)
  • Electronic brake control module (EBCM)
  • Instrument panel module (IPC)
  • Powertrain control module (PCM)

Does the scan tool display any DTCs?
Go to Step 4  Go to Symptoms - Antilock Brake System 
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 DTC B1000, B1007, B1440? Go to Diagnostic Trouble Code (DTC) List in Body Control System Go to Step 6 
6 Does the scan tool display DTC B1327, B1328, B1507, B1508? Go to Diagnostic Trouble Code (DTC) List in Engine Electrical Go to Diagnostic Trouble Code (DTC) List