Live Chat:
abs warning light has been intermittently coming on in our GMC Jimmy 2000. Today the brakes
completely quit working during a stop. The regular brake warning light never has/did come on. Placed
vehicle in park, turned off engine, and restarted without further incident, except of the abs light continuing to
light periodically. Taking the truck to have codes read, three were found. Two for the front right wheel, and
on for the rear right wheel. All three pertaining to sensor failure or intermittent failure. Wouldn't there need
to be something wrong besides a sensor, for the brakes to fail?

Did the pedal go all the way to the floor with no stopping power, or was the pedal sort of bouncing / fighting

It was a little of both. At home later, we turned the engine off, checked the brake fluid level, and it was fine.
Started the engine, and tested the pedal... it almost goes to floor now.

That is odd to loose braking because of a
ABS problems. Although with codes for 2 different speed sensors,
i can see happening since the ABS computer thinks those 2 wheels are at different speeds than the others
so it tries to compensate. You would need to get thee ABS repair done and re-evaluate the regular brake
operation, but i would think it fix that too.

So, it is possible that changing brake sensors, could fix a braking issue like this, and not it be some other
type of brake issue? Since the ABS, is not the brakes?

Yes. Two wheels fighting the other 2 wheels would cause poor braking. The pedal being low now would not
be related. You may just have worn brake pads.

What do you think could make two of the sensors fail/go bad at the same time?

Just coincidence or possibly one of the sensors codes did not turn on the ABS. Some codes come and go
so fast, the light does not come on, but the computer still stores a code. So, when another problem came up
and set a light, the codes where scanned, and all codes show up, no matter when they occurred.

Oh good point. So if it were your vehicle, would you begin with replacing the pads or the sensors?

I would get the ABS fixed first. If the computer sees different wheel speeds, it will engage ABS activation no
matter how hard or soft you are hitting the brakes. This will give the bouncing / fighting feeling in the pedal
and poor braking. Note: just because you have a code for the right front sensor does not mean for sure it is
the sensor.

Well all three codes are for the right side of the truck, and two are for the front, so, it does seem logical that
the issue stems from the right side... but if not the pads or the sensor(s), no leaking, what else could it

Another common problem for a front wheel speed senor is a broken wire in the small harness to that sensor.

Oh, alright, thank you for the information, and you time!
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GMC Jimmy Brakes Went Out- ABS Light On