For a few weeks now Ive had the 'Check rear lights / Cruise control not working' warning appear on the dash after a few mins of driving. After checking everything I could (from previous threads) I concluded it must be the brake light switch as all else seemed ok. Was planning to repair/replace at some point soon.


However, what intrigues me is that BEFORE the warning comes on the cruise control doesn't work at all. Is this the cause if the problem perhaps, and not the brake light switch - ie is there some issue with the steering wheel buttons that the ECU is picking up? Is there any way of checking?


Cheers

 

Don't waste time with other stuff, it's the brake light switch.
You might try--trying to grab the switch and move it some. It will be hard considering where it is and it more then likely won't move at all, but just wiggling it may be enough. If that doesn't work, get the better half, or a friend to help, and replace it. When you try putting the new one in, you'll see why a friend will be loads of help.

 

Yep, it's the brake pedal switch. You have the classic warning messages. Repair or replace it, and as advised above, it is definitely a two-person job. Remove the drivers seat for more working room and greater comfort for the poor sap stuck with the task of working on his/her back while crammed underneath the dash. Make certain the smaller person gets that assignment....

 

What is it that usually goes wrong with these units? Is it possible to repair the brake switch?

 

There are two microswitches, and they can be replaced. A search of the forum should locate the thread where the procedure was explained, or someone will come with the information.

 

I was able to do it myself though it was a royal pain. I took the switch assembly off the bracket from underneath after carefully taping the sound insulation/padding to the sides so I could see up there a bit. I didn't have to take the seat out either but I am only 5'5. Was a very uncomfortable position to be in and every time you touch something loose crud falls down into your eyes. I used a small ratchet and you only have to take the top bolt all the way out. The bottom one you can just loosen. I replaced the 2 microswitches. I found compatible ones on Ebay for $3 each including shipping. Putting it back in was way more fun. Hint: You have to use something like a stick to hold the brake pedal down while you put it back in. Then after all that it didn't fix it! Turns out in my case it was the ECU that was bad. Soon after the ECU failed massively and I had it rebuilt and that fixed the CC also.

Dave

 

DaveInVA. do you know the part number or any info on the micro switches you used? There like a million different ones. Thanks Tim

 

Is the car drivable when the switch is removed? Or does it go into a "failsafe" reduced performance mode?

 

Not had time to do anything about this issue over past couple of weeks, and the message is still occurring every trip. I think I know I will have to bite the bullet and buy a new switch (£102 from SNG Barratt) and then spend another £20 (at least) on bribing my 14 yr old daughter to squeeze under the dash, but thing is, I'm not getting any codes on my OBD11 reader (just the ok P1111), even when the amber warning bar/message is there right in front my eyes. Is this because:-

1. my Torque Pro reader/app only deals with generic P codes, or
2. is it because the brake light switch failure never sends an error code, or
3. is it because its not the switch after all?

I know the winner probably wont be no.3, but just in case...


Jules

 

Electrical faults do not always generate OBDII codes. And when they do, it may be a B or C code that a generic code reader cannot see. Your most prudent solution remains replacing or repairing your brake pedal switch....