What do the trouble codes on GM ABS mean?
The ABS light will flash the trouble codes 3 times each and then repeat them. Here is a list of the GM trouble codes, and what they mean. Codes 12 and 14 aren’t trouble codes, but may appear to indicate normal operation. 21 – right front speed sensor or circuit open. 22 – missing right front speed signal. 23 – erratic right front speed signal.
How to check trouble codes on a 1994 GM?
Checking trouble codes from your 1994 GM vehicle does not require the use of special equipment, such as a scan tool. Extracting trouble codes from your vehicle lets you track down and diagnose faulty components in an expedited manner. The computer uses the “Check Engine” light located on your dashboard to display the stored trouble codes.
How to determine what ABS system a Chevy truck has?
Visually inspect the rear of each brake assembly to find out whether you have front wheel or rear-wheel ABS. The ABS control module has wiring harnesses that go into the back of the wheels with vehicle speed sensors on them. The wheels with electric wires going into the back of the brake assemblies are wheels that have ABS equipped on them.
Where are the diagnostic connectors on a 1994 GM?
Locate the black rectangular shaped diagnostic connector, which underneath the driver’s side dashboard panel near the floorboard. Bend a small metal paperclip into a “U” shape. Insert the pointed ends into the furthest two top-right diagnostic connector terminals.
Where is the ABS control module on a Chevy truck?
The ABS control module is mounted on the hydraulic modulator assembly, which General Motors calls the Electro-Hydraulic Control Unit (EHCU). One variation is the EBC4-VCM system on 1994 and up Chevy S- and T-series trucks. On these applications, there is no ABS control module on the modulator.
What are the symptoms of a bad ABS control module?
1. Unresponsive brake pedal. In certain cases, depending on the model of vehicle, when the ABS module fails, the brake pedal may become unresponsive. This is an obvious problem, as an unresponsive brake pedal will not stop a vehicle, or will not be able to do so in an adequately safe manner.
When did GMC add 4 wheel anti lock brakes?
In 1992, the four-wheel anti-lock braking system was added to the two-door S- and T-series trucks, Suburban, full-size Blazer/GMC Yukon, Geo Tracker and the limited-production GMC Typhoon. The 4WAL system is a nonintegral, four-wheel, three-channel ABS system with a conventional master cylinder and brake booster.
How does the ABS system work on a car?
The ABS system is made up of the ABS module, and ABS sensors at each wheel. The sensors detect wheel speed, and will send a message to the ABS module to rapidly pump the brakes when it is detected that the vehicle is skidding or has lost traction.