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Old 01-01-2009, 04:16 PM
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Re: 93 Lumina Z34 Anti Lock Brake Light Just Blinks

Unplugging the instrument cluster should not have affected the Electronic Brake Control Module (EBCM). More probably, the code has been there forever and the lamp had failed.

The good thing is that the lamp is flashing, meaning that even though there is a problem, the ABS is still active.

Do the easy things first. Make sure the master cylinder is filled with the proper fluid. Make sure the center brake light is working, since the EBCM senses that as an input.

There is a switch on the brake pedal arm, switching a separate circuit from the switch contacts used for the brake lights, which signals the EBCM. There is another switch on the park brake lever/cable, and this is also used as an input to the EBCM. Verify that all those switches are working.

There is a power relay near the master cylinder/ABS-VI system, and both a main and secondary power fuses for the system. Make sure there is consistent power at the ABS-VI unit from both sources.

There are connectors on the valve solenoids as well as one for the modulator motor on the ABS-VI master cylinder unit. There is also a control connector there, and a connector for the brake fluid level switch. Make sure those are all clean and properly seated. Verify that the normally closed switch contacts for the brake fluid level switch are closed - They signal the EBCM.

There is a power diode in the supply circuit. Make sure the diode is intact with an ohmmeter test.

You can find relevant schematics on the www, or I might be able to post some.
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