How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 29534
Experience:  GM Grand Master Technician 2007. 14 years experience.
Type Your Chevy Question Here...
GM Tech (Cam) is online now
A new question is answered every 9 seconds

chevy malibu brake light stay on/changed brake light sensor

This answer was rated:

chevy malibu brake light stay on/changed brake light sensor there still on
The brake warning light will come on to tell you if the system is low on fluid. Or if there is a rubber gasket in the master cylinder cap that has fallen down and it hitting the sensor in the master cylinder. It will also come on if there is an imbalance in the system or the combination valve is bad. If it is the same light that comes on to tell you that the parking brake is set, then it could have a loose or broken park brake lamp switch on the parking brake assembly. I don't know which sensor you replaced, or which warning light is coming on for sure. If it is the ABS warning lamp, then the computer needs to be scanned to see what codes if any are stored related to the failure. Check the things I have mentioned and then update me and give me as much information on it as you can. The more I understand the problem and what it is related to, the better chance I can help you. Thanks
Customer: replied 8 years ago.
brake lights at the back of car stays on when no one is pressing brakes.brake sensor at pedal was changed. brake lights at back of car goes off when you press pedal
Thanks for the response. Looks like we misunderstood the problem. We thought you were talking about the brake warning lamp on the dash staying on, This is a lot different. Sounds like you have already replaced the stop lamp switch at the brake pedal. (is that is not so, advise) Sounds like somehow you are getting a back feed in the circuit and the stop lamps on the rear of the car are working backwards from normal. (again, if not correct advise) Think this is a real unusual situation and one I have not run into before, so I will be needing to conger with some of the other experts here to see if we can get some ideas for you. We will also need to know what year model your Malibu is, so I can do a bulletin search on it to see if GM has had this happen often enough to have issued any tech bulletins on it. ? Thanks
Customer: replied 8 years ago.
Yes, I did replace the stop lamp switch at the brake pedal. Yes again the stop lamps on the rear is working backwards. The year of the car is 2005 Malibu with a 4 cylinder engine.

Thanks Bob
Thanks for the reply. I will do some checking on it and see what I can come up with. It may be a while, so be patient with us. Some of the other guys here don't sign on until late in the day as they work full time regular jobs too. Thanks
Customer: replied 8 years ago.

okay I'll be waiting for your response
Well, so far it is not looking good. I have talked to several fellows and everyone has ideas, but no one so far has run into this problem. I even checked with GM and they have no bulletins that pertain to this particular problem. So, I am going to give you the information that I have so far and then I will opt out of the question, which will open it back up for any other experts that may have an idea. That way, they can also jump in and post to you with any information that they may have. If you do not have any after market accessories connected to the car and assuming that the rest of the lights work as they should. Running lights, turn signal etc. Here is what I have come up with so far. Everyone so far agrees that someplace in the system there is a back feed that is causing the problem. Meaning one circuit that should not be involved, is somehow supplying voltage to the stop light circuit when it should not. In the under hood fuse box, check the fuse that says ABS, it is a 10 amp fuse. In the rear fuse box check fuse number 6, it is also a 10 amp fuse labeled stop lamps. Also in the rear fuse box is a relay named park lamp, in spot number 27. See if you can find another relay that looks the same as this one and try to substitute it for this one and see if it makes any difference. There should be at least one more relay in the car that will be the same. The rear fuse box is in front of the left rear wheel well, in the rear compartment. All most everyone agrees that if it is not a fuse or relay, then there is a problem either inside the multifunction (turn signal) switch or in the BCM, (body control module). The problem with testing these 2 items is that it needs to be done with a class 2 scan tool like the Tech 2 that GM uses for testing and programing control modules on the car. If by some quirk, you also have the service engine light or some other warning indicator coming on, on the dash, then the computer needs to be scanned anyhow to see if there is a code related to the failure being stored in the BCM. If the things I listed all check ok, then the next step will be to monitor and function test the system with the class 2 scanner to see what component may have failed or is not working with in normal operating perimeters. I hope some of this is helpful. But, as I said earlier, this is a really unusual problem and not one I have seen before. Obviously neither have any of the fellows I talked to. But because of the high cost of some of these parts, it would be much better to diagnose it properly with the scanner, than to just start throwing parts at in an attempt to fix it. I will also opt out so that anyone else who has some ideas can get involved with you on it. Thanks
Welcome, I have read the conversation between you and Bob. I have one question. Would you post the VIN of your car so I can be certain which series of Malibu you have. The reason I need to know is the new style has a brake pedal position sensor rather than a switch that requires a calibration procedure.
Customer: replied 8 years ago.
This malibu has the brake pedal position sensor. thanks for your patience

Thank you. What you need to do is perform the calibration for the new sensor. It is listed below.


Calibration Criteria

The brake pedal position sensor (BPPS) receives a low reference signal and a 5-volt reference signal from the BCM. Whenever the brake pedal is applied, the BPPS applies a variable voltage signal to the BCM through the stop lamp switch signal circuit. The BPPS calibration must be performed after the BPPS or body control module (BCM) have been serviced. The calibration procedure will set BPPS home value. This value is used by the BCM to determine the action of the driver applying the brake system and to provide this information to the vehicle subsystems via the class 2 communication bus.

Calibration Procedure

  1. Install a scan tool.
  2. Select Diagnostics.
  3. Turn ON the ignition, with the engine OFF.
  4. Select the vehicle.
  5. Select Body and Accessories.
  6. Select Lighting Systems.
  7. Select Special Function.
  8. Select BCM.
  9. Select the BPPS calibration procedure and follow the directions displayed on the screen.
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 29534
Experience: GM Grand Master Technician 2007. 14 years experience.
GM Tech (Cam) and 9 other Chevy Specialists are ready to help you