Table B ABS Indicator Inoperative With No DTC(S) Set

ABS Indicator Inoperative With No DTC(s) Set (Part 1 Of 2):

ABS Indicator Inoperative With No DTC(s) Set (Part 2 Of 2):

ABS Indicator Schematic:

CIRCUIT DESCRIPTION
The "ABS" indicator lamp driver circuit runs from the Instrument Panel Cluster (IPC) through the Lamp Driver Module (LDM) to the EBCM/EBTCM. The IPC supplies voltage to the indicator lamp. The EBCM/EBTCM controls the "ABS" indicator through the LDM. The LDM acts as an inverter, when the EBCM/EBTCM supplies a ground for the LDM the indicator lamp remains "OFF." When the EBCM/EBTCM removes the ground for the LDM, the indicator lamp turns "ON" by using the ground at the LDM terminal "D."

DIAGNOSTIC AIDS
- It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
- In order for the "ABS" indicator lamp to come "ON" there must be battery voltage at terminal "B" of the LDM, and a good ground at terminal "D" of the LDM.
- If the indicator lamp does not come "ON" and there are no DTC(s), then the cause is either a malfunctioning LDM, CKT 875 is open, no power or ground for the LDM, a malfunctioning IPC, or a damaged "ABS" indicator bulb.
- If CKT 852 is open, shorted to ground, or shorted to voltage, the EBCM/EBTCM will set a DTC.
- If the battery feed to the IPC indicators is open, then more than one indicator bulb will be inoperative.

TABLE TEST DESCRIPTION
The numbers below refer to step numbers on the diagnostic table.
2. Checks if the EBCM/EBTCM is not capable of removing the ground for CKT 852.
5. Checks for a short to ground in CKT 39.
6. Checks for voltage at LDM.
7. Checks for voltage from IPC.
10. Checks if LDM has a good ground.