Service brake system warning out of nowhere

SNUBFIGHTER

MEMBER
2005 CHEVROLET TRAILBLAZER
4.2L
6 CYL
4WD
AUTOMATIC
203,000 MILES

Okay, so I went to get dinner this afternoon (super warm weather at -12 in good ol Minnesota). Stopped for gas, no issue. Drove to the restaurant, still nothing. Come out of the restaurant 15 minutes later and start up the truck and bam! I've got a constant chiming, ABS and brake lights on the dash and the Service Brake System message on the HUD. Shut the car off, restart, same result. While driving the brakes were fine, felt the same as they have since I can remember when, lights stay on the whole way home. When I checked the fluid level, the master cylinder reservoir was full up to the neck right below the cap. I did the front brake pads about 6 months ago and until now have had no issues, and the e brake is 100% down so I know that's not the issue. Is this a fluke of the weather or am I missing something here?

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,709 POSTS

Hi,

Chances are it has to do with a wheel speed sensor. That is where I would start. If you have access to a scanner that can read ABS codes, check that first if you already checked the ABS fuse. I attached a pic of the fuse and location in the attached picture. If the fuse is good a then we have to check each wheel speed sensor to make sure they are working.

Here is a link that explains how it is done. Take a look through it and see what you find.

https://www.2carpros.com/articles/abs-wheel-speed-sensor-test

Let me know.
Joe

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