01 Brake Light in Reverse

[david-b]

What's going on guys? Couple issues

Couple things before my questions. ABS, Security, CEL, SES, and traction lights are all on. I guess the ABS sensor on one of the hubs are bad, causing a couple of those lights to turn on.

1) I can drive fine, no problems and the brake light will randomly turn on at some point in my driving. I can get it to turn on right away by putting the car in reverse, then to drive. Light comes on pretty instantly. Any ideas on this?

2) CEL is for MAP and front O2 and had some driving issues. Fixed both, but CEL is still on. Pulled negative terminal for half a day, and still on. Car running perfect, so I know the problems are fixed. Does this car have a special way to reset the ECU? Also with the service engine soon? Autozone said they can't reset the code (calling BS on that one)

Thanks

[thephantom1492]

Originally Posted by david-b

What's going on guys? Couple issues

Couple things before my questions. ABS, Security, CEL, SES, and traction lights are all on. I guess the ABS sensor on one of the hubs are bad, causing a couple of those lights to turn on.

1) I can drive fine, no problems and the brake light will randomly turn on at some point in my driving. I can get it to turn on right away by putting the car in reverse, then to drive. Light comes on pretty instantly. Any ideas on this?

2) CEL is for MAP and front O2 and had some driving issues. Fixed both, but CEL is still on. Pulled negative terminal for half a day, and still on. Car running perfect, so I know the problems are fixed. Does this car have a special way to reset the ECU? Also with the service engine soon? Autozone said they can't reset the code (calling BS on that one)

Thanks

I'm not an expert, but it would seems like you have an electrical problem. Check to be sure that your ground from the battery to the body is in good condition, same from the ground to the engine.

If they look fine, I'ld check to see if you have corosion at the PCM and BCM connectors...

With multiple simultanious, non related problems, you want to start by where all the problems have a link. Sensors are ground referenced in most case. If your ground is faulty, it will misread many sensors. For some sensors it will still be in the limits, for others it will be way outside the normal range. Corosion can also be a real problem, it can short pins together, cut wires and make a bad contact. Shaking the car can move the wires, making the problem appear/disapppear temporrary. If you have a loose ground wire it can do the same thing too...

As for the code reset, some of the code "can't" be turned off, because the trouble is still present. Ex. you can't turn off the ABS if your wheel sensor is disconnected. Reconnecting it would automatically turn off the error, but might still be in the error log, or not.

[doctorhrdware]

The ABS and the tractions light will remain on until the defective hub is replaced. In order to find which hub is bad you need a DTC scanner that can read the extended GM codes like the anti lock brake and the transmission DTC codes. That way you will not be throwing parts at the car. It will tell you which hub or hubs that are bad.

[skeeter123]

Agree. A-Zone isn't BS-ing you, the freebie code reader they use won't read/clear ABS codes.... U need a more expensive reader that can read the ABS codes to tell you which one is bad.

You should check the speed sensor wires from each of the wheel hubs (front and rear). Disconnect the wire from each hub and feel along the wires to see if there is any crack/break, particularly where the wire bends ~ 6" back from the hub. If you have a ohm-meter you could check the resistance of each sensor, I think it should be between 1K - 1.5K ohms. If one is very different from the others, that's your bad bearing/sensor. When u re-connect the sensor, put some dialectric grease on the contacts.

Oh, and when you say the brake light comes on, do you mean the dashboard brake "warning" light? If so, there's an e-brake sensor in the console where the gear select and emergency-brake levers are. Its job is to detect when the e-brake is on, and light up the brake/warning light. It could be that when you're shifting R to D the "e-brake on" switch is being jostled/bumped and triggered somehow into thinking that the e-brake has been applied. Check the e-brake lever and associated brake-switch.

...Now that I think about it, your title says "brake light in reverse", but then you say the light comes on immediately when you put it into drive. Sounds like your car thinks the e-brake is on all the time; I would defintely make sure the e-brake lever is going all the down when you release it, and eyeball the e-brake sensor/switch to make sure it hasn't moved out of position.

Hope this helps.