jclemen

Yep, read all the threads related to this, Stop Lamp Switch. I did the brakes on my 03 e320 6 months ago, no issues. Did the front brakes tonight, I still have the 'wear' message. I pulled the wheel on each side to double check the sensors, no luck, they're in there and correct. I can do the SLS replacement, but I suspect I'll have to drive the damn thing for 2 months before the new pads wear down so I can make an appt with the dealer. Gee, these pads look brand new, and there's no record of the work! The things people do to save $600...
Feedback?

my06clk

I know you stated that you've checked the sensors, but
The wear message is just a signal to ground somewhere at one of the sensors, so Either a sensor was installed incorrectly or is faulty.
Or the connector has fused together.

best way to find out is to unplug the front and see if the light goes out. if it doesn't go out unplug the rear. the light should go out when you unplug the sensor giving the fault.
You can also go back past the connector and remove that part of the harness temporarily to troubleshoot the plug.

If you spend another $150 troubleshooting, you still come out better than spending $600 so don't give up yet. We'll help you solve this.

jclemen

Good idea, didn't think of the unplugging sensor trick. I'll do that tomorrow and check-in. Thanks for the reply!

jclemen

Quick question: Do I unplug the sensor from the pad or from the caliper or both?
Thanks...

my06clk

Caliper is easier.

jclemen

Caliper it is then. Thanks. I drove the car today, normally my wife does, and the message was intermitent. Sometimes it was 0 malfunction and would stay that way for awhile. Then on the next trip, it would throw the error.
I'll yank the sensor tomorrow night, thanks folks for the feedback...

jclemen

I'm late reporting, I know. Busy schedule. I unplugged the sensor at all three wheels, light is still on. I'll do the same test, except this time, pull the harness prior to the sensor.

I did not disconnect the sbc during this recent test. Is that correct? If not, is there an order to doing the test?

jclemen

Replaced the stop lamp switch ($15), still with the error. I'll move to the inner harness, anyone have a specific online vendor to use for that part?

Thanks

mleskovar

Are the sensors on the E class different than others? I thought the wear sensors are just a loop of wire that trips the light when the loop is worn through. Pulling sensors in this case wouldn't make the light go away. Isn't there a two pin connector on the sensor lead? There should be a short between the two pins on the lead with a good sensor.

starbrite

That's correct...he needs to install a jumper.

jclemen

Thanks for the direction. I've been disconnecting the sensor from the 2-prong side, not from the pad itself. I was told in this thread that disconnecting in this manner would indicate which sensor was bad. I remember seeing this in another related thread as well.
I'm willing to try the jumper solution, but would need some more detail as to exactly what needs to be done.
Thanks

jclemen

I should also add the sensors and pads are all new.

mleskovar

First understand how the sensor works. The sensor is simply a loop of wire. The "WEAR" light comes on when the loop is worn through because the pads have gone down to that point and the rotor has ground off the plastic 'sensor' end and through the wire, opening an electrical circuit that should be closed. When you plug a new sensor in where one has worn through, and restart the car, it senses a closed circuit and the light doesn't come on. Unplugging the sensor simulates a worn sensor. Using an ohm meter on the sensor is the way to determine if it's open (worn through), or closed (new). An alternate way is to get a new sensor and just plug it in to each wheel without removing the old one from the pad. Cycle ignition and see if the light goes out to find the offender. I believe on your car all wheels have sensors?

jclemen

Thanks. Three sensors on the E, I know that the front two are different. I haven't been able to find just the sensors forsale. If anyone has a vendor for these, I'd order them up tomorrow.