Hello all,

I just changed my front pads and rotors. When I did a test run, the esc would turn on and do its thing, then shut off. It seems to happen speradically. Anyone know what caused this? When it does turn on and I try to brake, it makes stopping difficult. When I slam the brakes when the esc is not triggered, it stops perfect.

Any ideas? Could it be that the pads are slightly pushing against one of the rotors, thus causing one wheel to spin slightly faster than the other? Do they need to be worked in more? Anyhelp would be greatly appreciatted.

Thanks!

 

did you press all 4 of the pistons in when you installed the pads?

you might have to bleed the lines... possibly?

 

We did push the pistons in at differnt times. We did one side then the other.

Also, I dont think its a bleeding issue, as it happens when the car is just coasting.

 

Sounds like you did something with the ABS that you shouldn't have. They brakes will trigger the ESC sometimes if you spin the tires while making a slow turn (one wheel spinning at a time). It will reset by cycling the key. Something is causing to sensors to not read equally. It's dealer time!

 

Im not sure what we could have done wrong. Pretty basic procedure. Also, the more I drive, the less it seems to happen. Anymore thoughts.

 

Sensor position get bumped/changed?

 

I will definatly check the sensors tomorrow. Anyone have a picture or diagram of the ESC and ABS sensors inside the wheel well?

 

I didn't read the whole thing but this might give you some places to look for your problem. There are plenty of other sites that could help too. The ESC could very well be turning on because of a brake problem. Judging by your symptoms it is definately brake related. Check the wires to the sensors, the sensors themselves by measuring the resistance across each one and wiggle the wires at the same time if possible, and clean all areas around the sensors. Resistance should be around 1.5 K ohms. If there are no obvious, visible, problems found I'd call the dealer or brake shop to have it checked out. There's no bigger surprise than stepping on the brake pedal and nothing happens.

http://www.asashop.org/autoinc/august97/service.htm

 

Does the ESC and the ABS share the same sensor? Do you know where they are located?

 

Update:

I rechecked the sensors on both front wheels and everything looked perfect. I also retourqued the wheels to spec. After a long drive, the ESC did not activate even after several hard stops. When I was on my way home, after a slight stop, the ESC shut itself down and now the light is permentaly on with the "service esc" message.

I made an appointment with the dealer on Wednesday.

Strange thing is, once the ESC shut itself down, the car drove perfectly. The esc no longer randomly acitivated itself. The other weird issue is that upon startup of the car, if I pump the brakes a few times before moving, the brakes feel like they need to be bled. Once the car roles a few feet, that feeling goes away and the brakes feel perfect. It only happens upon startup.

Any thoughts?

 

Press and hold the traction button to turn it off totally lol

 

I think your ESC sensor is somewhere on the steering column. I can't find it, but someone had an issue with it before. Either way, the dealer will figure it out.

 

When I changed the pads in the front, I didnt reuse the detachable backing plate on the stock pads. Should I have? The new pads already had a backing plate so I didnt think it was needed. Just a thought.

 

yes, you use those... those are the shims that go between the piston and the pad... possible that the piston is sensing the space between it is different due to not having the shim there.. and that could be a reason for the ESC problem..

 

It wouldn't have anything to do with it. ESC uses a combination of measuring the ABS hub sensors, steering angle sensor, and accelerometers to determine if it needs to engage. None of those have anything to do with the backing pad which is simply used to reduce squeaking of the brakes. The backing from the old pads does not need to be used with the new pads if they came with their own.

 

no..there is no sensors on the brake calipers lol (if that was the case we'd prob have a brake life meter!), those shims aren't a big deal. esc/abs i believe are through the same sensor, but what about your fluid level, JW not that it might have anything to do with it but when pressing the pistons back you didn't loose any fluid did you? did you check after you were done

 

I'm betting ABS sensor.

edit: Did you rotate your wheels?

 

No, I did not rotate my wheels. The dealership said it was the steering sensor, and recalibrated it. So far, everything seems fine.

The only other issue now is that upon starting my car in the morning, before I drive, if I pump the brakes a few times, the pedal gots notchy, almost like the brakes need to be bled. This goes away quickly, and once the car is moving the brakes feel mint.

Thoughts?

 

Mine are like that. Wait till you drive in the rain. Woohoo!

 

prob just the brake booster, maybe not enough vacuum at start up when its cold maybe?