I asked my dealership if they have a qualified Hybrid technician and the service scheduler told me they have two master techs that have been through the Hybrid training. Is that the same thing?

 

Yes, those would be the guys you want, and your dealer has two of them.

 

Turns out the problem was the brake pressure control module. It shorted out. They've replaced it and everything seems to be working fine now. The squeeking I heard in my brake pedal the day before the failure was the sound of the sensor failing - according to them.

 

Jimmy,
do you mind elaborating more on the squeeking noise comming out from the brake pedal.
did it happen while you had your foot on the brake pedal for a long period of time(couple of minutes) while you where on drive and not moving?
did the sound come out from the interior (brake pedal area) or exterior(engine compartment area underneath vehicle?

I have experienced some whinning sound when I place my foot on the brake pedal for a long period, I just want to make sure it is not the same sound you had expereinced

Thanks
Guss

 

Hi Guss,

The squeek is best described as coming directly from the pedal, almost like it was dry/unlubricated where the pedal hinges from the subframe. If you take a look at the video I posted you can hear the squeek happen as I put my foot on the brake pedal. The service manager told me that was probably the sound of the module as it was failing, now that it is fixed it no longer makes that sound.

The sound started about a week before I actually lost my power assist. I chalked it up to a change in the weather, it gets kind of wet and nasty here this time of year (Seattle, WA).

The paperwork from the dealership references a TSB on the matter, when I get home this evening I'll see if I can post up a scan of the work order.

The video is here - http://www.youtube.com/watch?v=WuxN-...ature=youtu.be

 

Thanks Jimmy, much appreciated.
This is totally different from what I had experienced

glad they managed to fix it for you

 

radio off and door closed would help us listen more to the brake sound j/k

 

It sounds like the same thing happened in my 2009 Tahoe Hybrid. The brakes got steadily more and jerky. Suddenly, I had NO brakes. I was fortunate that I was not in a bad situation when it happened.

The car sat for a few hours and I thought to try it again before calling for a tow. Surprise! My brakes were back. And they didn't go out again completely until I was almost at the dealership!

A software reload fixed the problem. But what is wrong that it all went bad in the first place? How is somebody not going to be killed by this problem?

 

I didn't know you could install software in hydraulic fluid

 

"I didn't know you could indtall software in a hydraulic fluid resovoir."

-- My wife still doesn't quite understand it. There's a regenerative braking system that slows the car using magnets. This helps recharge the battery pack. If more braking power is needed, the conventional brakes kick in. A computer program controls how much of each braking system to use based on the inputs from the brake pedal and other sensors.

If the 1's and the 0's get scrambled, then NO brakes get applied. Thus, a software reload of the brake control program fixes the problem.