leventor

Hi
I have a 07 gl450 with 77K miles on it... Brake wear light came on and I have the front rotors and pads/sensors replaced..

But the brake wear light does not go off, within few minutes of turning the car on, the light comes on, generally when I move the steering wheel right or left, and some times without doing nothing like when warming up the car in the morning..

I suspect either the sensor is faulty, or the sensor wiring is faulty, the shop said there can be a short in the wiring harness but I dont believe him yet, since this problem showed up after he replaced he pads and rotors.

Any ideas what it can be or how I can debug the issue ?

thanks

wally AMG

+1 / or sensor is loose

Captincvmn

I'm gonna revive an old thread here. It's applicable to my situation.

I just replaces aces all four positions on my '07 GL320. Brake wear indicator was on for the fronts. I did one wheel at a time and pumped up the pedal after each one.

When I was done I was quite disappointed to find the indicator came on again after I restarted the car. I removed both passenger wheels and double checked the indicators and plugs. Should I purchase two new sensors to replace the new sensors just in case I *****ed one up while I was replacing the pads?

ItalianJoe1

It's almost always the sensors. If you didn't change them all, change them. You can pull the codes and it will specify which sensor is at fault. Be sure they are routed properly and clipped into the pads correctly, do not re-use them, they can crack when removing and even though they look fine may still trigger the warning.

Captincvmn

I did have the new non sensor pad installed on the front and I pulled the sensor off the one in the box (stupidly) and wound up having to pull the pad out of the pistons anyway. Perhaps I'll get another new sensor and try that.

Anybody know now how to test sensor with a meter? Are they simple continuity or is it an ohms reading?

angelglo

simple continuity will work. it is triggered when there is an open circuit. I found the rear wires wear after a period of time. it was hard to find mine but the wires had worn from the rear suspension travelling up and down. The broken wire was right at the zip tie

Captincvmn

Found my issue. Front wear sensor tested good BUT was worn through at the clip causing it to ground out.

ItalianJoe1

That's why we change them every time, regardless if the pad had worn down enough or not. Glad you got it fixed.