GM Service Manual Online
For 1990-2009 cars only

Object Number: 191381  Size: MF
ABS Components
Antilock Brake System Schematics

Circuit Description

The EBCM initializes a self-test when the ignition is turned to the RUN position. This internal self-test verifies that all ABS circuitry is operating correctly.

Conditions for Setting the DTC

Any condition within the EBCM which causes a memory error will set this DTC.

Action Taken When the DTC Sets

    • The ABS indicator lamp is turned on
    • The ABS is disabled

These DTCs are Permanent Latched DTCs, which indicates that the above actions remain true until the DTC is cleared using a Scan Tool .

Conditions for Clearing the DTC

    • Repair the conditions responsible for setting the DTC
    • Use the Scan Tool Clear DTCs function

Diagnostic Aids

DTCs C0271-C0273 are EBCM internal diagnosis trouble codes. Replace the EBCM if these tests show that the EBCM circuitry has failed.

Test Description

The numbers below refer to the steps in the diagnostic table:

  1. This step checks if the EBCM will Clear DTCs.

  2. This step checks if the DTC was set previously.

Step

Action

Value(s)

Yes

No

1

Was the Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check

2

Install the Scan Tool and attempt to clear the DTCs.

Did the DTCs clear?

--

Go to Step 3

Go to Step 4

3

Check the history DTCs and the data.

Was this the first time the DTC has set?

--

Go to Diagnostic System Check

Go to Step 4

4

Replace the EBCM.

Refer to Electronic Brake Control Module Replacement .

Is the repair complete?

--

Go to Diagnostic System Check

--