Humming Noise In Rear After Shut Off

cabledude · February 8, 2023

It's Tim, I think you misunderstood my post, I am not driving around with "suspect brakes", and I'm not getting a "third world brake job". The park brake isn't working! Nowhere did I say I was having issues with my entire brake system and I take offense at you insinuating this. I am simply asking if anyone had had similar problems with the PARK BRAKE or if the Brake System Control Module only controls the Electric Park Brake system or if it also controls the other brake functions. If it is only for the park brake system, and I can find a replacement module more reasonable than the dealers cost (I'm not against OEM parts, have purchased many in the past, and will do so if necessary). If it is a pull and plug in new module and others have not had issues doing it, I would be willing to try it myself. If it is more complex, I know my limits and might not try it myself. Only looking for feedback on others experience, not a snatchy reply on how safe you think my driving habits are.

Oscar Winner · February 9, 2023

The only brake control module that I can find listed is for the trailering brake. ACDELCO 84825497 is the part number.

The E brake is electric, so there has to be a control module for that I assume. I haven't replaced the rear brakes yet, is the e brake cable activated?

Tim - FYI the dealership charges $240 for just the front pads that you can buy the same ACDelco ones at Rock Auto for $40. Labor charges add more to the mix. Heck, I'm an engineer in the 1st world (are there second world countries?) who has done many brake pad replacements. I trust my work over an unknown technician at the dealership. I've been personally burned so many times by dealership service.

Oscar Winner · February 9, 2023

Figured out the rear brake e brake. There are electric actuators that attach to the caliper. It basically squeezes the pad rather than the hydraulic piston in the caliper. They're about $45-65. Looks like an easy bolt on with a wire lead.

cabledude · February 9, 2023

That's interesting info on the actuators. I gather from the dealer, that the signal is reaching each wheel, but there must be a module that sends the voltage to the actuators and that is what they are indicating is bad. He did write down for me that it is a Brake System Control Module Part number 86788483, but so far when I looked it shows Electric Brake Booster Control Module, or takes me to trailer brake control modules. Price is much more reasonable, but I would need more info about if this is the correct part and what is involved in changing it out before I would attempt it myself.

Oscar Winner · February 21, 2023

If you're getting a signal to the actuator, and it's not working, odds are the actuator is the issue. It's just a relay in the actuator. Brakes are in a abusive location, so things will happen.

You can check the actuator response with a tester, but if you're into the part and it takes all of two bolts to replace it, just replace it. You did all the hard work getting into it.