Table B Antilock Indicator Inoperative

Table B (Part 1 Of 3):

Table B (Part 2 Of 3):

Table B (Part 3 Of 3):

ABS/TCS Circuit Schematic:

CIRCUIT DESCRIPTION
When the ignition switch is first turned to RUN the Electronic Brake/Traction Control Module (EBCM/EBTCM) goes through a self-test lasting 2-4 seconds. During this test, the EBCM/EBTCM grounds terminal 52, causing the amber ANTILOCK indicator to light. This serves as an indicator bulb test. The EBCM/EBTCM also grounds terminal 34, energizing the main relay. This removes the indicator ground path provided through the antilock diode and the main relay contacts.

When the self-test is completed (and no faults detected) the EBCM/EBTCM removes the ground at terminal 52, turning OFF the indicator. The main relay remains energized.

When the EBCM/EBTCM detects a malfunction, it grounds terminal 52 causing the amber ANTILOCK indicator to light. (Note: The EBCM/EBTCM also de-energizes the main relay creating a redundant ground path.)

When the EBCM/EBTCM is disabled for any reason (i.e. open ABS fuse), the main relay is de-energized. This provides an ANTILOCK indicator ground path through the antilock diode and main relay contacts, and causes the indicator to come ON with no DTC being set.

DIAGNOSTIC AIDS
Possible Causes:
- Open in CKT 1451, 852, 39, 351, or 1633.
- Open I/P fuse.
- Open bulb.
- Short to voltage in CKT 852.
- Open or shorted antilock diode.
- Main relay fails "engaged."
- Short to ground in CKT 39, 852, or 1632.