ABS Indicator light on?

1997 MAZDA B4000
80,000 MILES • 4.0L • 6 CYL • 2WD • AUTOMATIC
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MERV KRUK
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  • 1 POST
1. If I depress the brake pedal and keep it depressed, then turn on the ignition, the ABS indicator comes on, extinguishes, and stays off. However as soon as I release the brake pedal, seconds later, the indicator comes on and stays on until I turn the ignition off. If I pump the pedal as the vehicle is running and ABS on, it remains on until ignition shutoff.

2. If I turn the ignition on without depressing the brake pedal first, ABS comes on, extinguishes, then comes back on and stays on until I turn the ignition off. It makes no difference if I depress or pump the pedal while the indicator is on. It stays on until the ignition shuts off.

In either situation the vehicle is not in motion.
Oct 7, 2022 at 12:08 PM
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CARADIODOC
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  • 34,306 POSTS
Pressing the brake pedal doesn't have anything to do with the problem. It only affects when some system tests are temporarily suspended or resume. The Anti-lock Brake Computer has detected a defect and set a diagnostic fault code, then it turns on the yellow warning light to tell you. The first step is to have the fault code(s) read and recorded, then we can figure out the best course of action. The people at most auto parts stores will read fault codes for you for free but be aware they are in the business of selling parts. No fault code ever says to replace a part or that one is defective. They only indicate the circuit or system that needs further diagnosis.

Also, many of the code readers used at auto parts stores only access the Engine Computer. Some of the newer ones can access Air Bag and Transmission Computers, but there can be dozens more they won't access. For those you may have to visit the dealership or an independent repair shop with a full scanner to have the codes read.

Once you know the code number(s), post them in your reply and I'll look up the definitions for you. That will give us a starting point.
Oct 7, 2022 at 12:50 PM