Hi all,

I currently have 2 missing and 2 disconnected brake pad sensors, yet, my brake warning light is still on. A couple of questions.

Does the warning light come on only from the pad sensors, or can something else actuate it?

Next, don't the sensors just rub through the insulation and then short across the rotor?
If so, it would seem all 4 disconnected would should not allow the light to come on.

Has anyone seen this before?

Thanks
Roger

 

The only way the light will go off is if you have new pads AND new sensors. Disconnecting them or having worn sensors will cause the light to stay on.

 

You can short the pins in the connectors at the rotors to get the light to go out.

 

Hi,

OK, thanks for setting me straight. I understood things to work just the opposite of reality (doh!)

So, I gather the sensors are all OR'd together somehow. I can fix that easily enough tonight. Great.

Just for sake of understanding, how does it work at the wheel end? I'd assume the pads get low and the sensor contacts the disc, rubbing part of the sensor's body off, breaking an internal connection. Makes sense, but it seems then the contacts would still make decent contact through the rotor surface. Obviously, my theory isn't quite right (that theory is why I assumed the opposite logic to the actual)

Can anyone unmuddy my fogged thinking (and excuse the mixed metaphor?)?

Thanks
Roger

 

To add to Slevy's comment, the brake wear system is a "closed" electrical system. In normal conditions current runs through the whole system and when a sensor wears out it breaks the current flow and the warning light comes on. Doesn't work the way you are thinking by grounding.

So if you are going to pull the sensors out you need to re-establish current flow by sticking a jumper in the plug or something on that order. I wouldn't cut the plug off and solder the two wires together because it would be tough to go back to original if you ever wanted to.

 

It appears that my brake pad wear bulb is out in my dash. I have the front two sensors disconnected and there is no warning message.

The previous owner decided not to replace the two rear sensors. Based on the discussion above, this would have caused the warning bulb in the dash to stay on continuously until it burned out.

How difficult is it to replace this bulb? I'm thinking that the whole instrument cluster needs to come out. While I'm in there I should probably redo the reflective material to help with general brightness at night. Also, replacing other bulbs might not be a bad idea.

Comments please...