Good question:) My car throws 3 lights at me (theft-deterrent, check engine and traction control), some error messages, turns of electrical steering from time to time, starts shifting hard and all gauges are going crazy. Where this electrical gremlin is sitting - that's what I want to know.

Happens chaotically - sometimes when starting the car in the morning, sometimes 10 minutes after driving it in the evening. Works well after driving for 20 minutes, parking for 5 and driving again. May be related to freezing temperatures here still, but want to track the issue while it's still cold - don't want to through that again next winter...

 

Sent a private message to donbrew, but will state the info here just in case someone else can help.

Where can I find some info on later models? 2006 engine electrics PDF has som differences if compared to my car. Mine was first registered on June 2008 (have no idea if it's 2007 or 2008). The electrician said that sometimes the signal coming from ECM to TCM is lost, but 2006 electrical doc shows that there is only 1 "socket" while mine has 2. Sorry if I sound stupid - not really good at electronics:) And my car is European version, so this may be the cause...

 

Looks like I found it - at least bought an access to one website containing tons of wiring diagrams. Sent those to the electrician - will see if it's enough...

 

Since the BCM was replaced by American Car a short while ago just before you bought the car, according to the thread
https://www.chevyhhr.net/forums/show...t=44843&page=2 - why not take it back to them again? They reflashed it last time, but it did not resolve the issues.

Being you bought the car there, I'd be beating on them to fix it - or take it back and get a refund.

 

Well, they had my car in the service 4 times after the BCM replacement (for free) and couldn't do a thing. Another Chevrolet Service is even worse - after 3 hours of searching they offered to replace the BCM to see "if it will fix the issues". I'm sure it won't since the car lives its own life - glitches appear chaotically, so it's probably a bad wire. You know cars these days are too complex and services don't have good educated electricians. All they do is replace parts one-by-one until an issue is solved. Now the service is offering me to replace the whole wiring for 962 EUR. Which is 1250+ USD. I don't want to sponsor their guesses:) Next time they might offer to attach a new car to the old hood and ask me to pay for it.

Anyway, electrician found the problematic wires and now he needs the diagram to solve the issue. Sent it yesterday - will see if that's enough.

Oh, and if anyone needs any repair docs - just tell me. ow I have an access to everything.

And seems like all GM vehicles have horrible electrics. That's my second Chevy and I was thinking about buying a Cadillac. If Caddies share identical wires/modules - I'll pass...

 

Hey everyone,

My car does this:

1. All gauges are "jumping" - I mean not registering current speed, RPM, fuel level etc. These just move quickly and chaotically and this can last for up to 20 minutes straight when it's cold outside. When it's warm - it may happen as well, but usually takes seconds.
2. Theft-deterrent icon lights up.
3. Shortly after - traction control icon lights up.
4. Sometimes check engine icon lights up, but that happens rarely.
5. Various error messages appear - mainly LOW FUEL (since the gauge can't register fuel level), STEERING FAILURE (see point #6) and SERVICE TRACTION.
6. When starting to drive - electric power steering doesn't work. It starts working a few minutes after while driving.
7. While driving slow - the car jerks quite heavily. As if lambda probe is faulty.
8. The car shifts really hard while driving.
9. Car's dynamics drops down while driving - as if I lost some horse power.

I've been struggling with that piece of "car" for 2 or 3 months now. 3 services, around 10 tries to fix it from their side (they even replaced a few parts - including BCM) with no changes. I even printed out a lot of solutions from this forum (mainly related to the fuse box, waterfall panel and some connection under the hood) - had no issues in those "problematic areas".

But, one idea came up recently and might have been confirmed from my side. I used a voltmeter while driving in hope that then the car starts to act crazy - the voltage will start jumping along with it. No changes when this happens, but I still saw something interesting - the voltage changes from ~15.0 to 13.0. It changes every second, but lower than 14.0-14.5 is not OK if you ask me (when driving). Even more - it can drop by more than 1 volt in 1 second. So, this is clearly an issue. Might this be the cause of all my problems? And if it might - is the alternator the only source for this kind of problem. I can think of 2 issues inside the alternator that can cause this.

Really want to fix the car because the only option I see is burning it down for insurance:) Joking.

 

Electrical issues can be a real pain to trace down. That used to be one of my specialties back in my old days.
Todays modern car electronics can make it harder to diagnois. But just like the old days, the battery is still the "base" of the system.
You should start there. Check and recheck all connections. Working forward until you can locate the voltage change. Maybe even try a different battery and compare.
Could it be the alternator? Sure. Or possibly the wiring to it.
The loss of power and jerky shifting sure sounds like it's going into limp mode.You need to have the codes read and post them here. With all the CEL lights popping up, you DO have some error codes stored .
Post up those codes and it may help us to help you.

 

Sounds like a ground (or a manpower line)
wire breaking contact....and everything cycles thru like a reboot every time it happens...

 

This is what, the 4th thread you have opened for the same problems since February this year?

If you keep opening up a new thread periodically like this, you end up starting the conversation from the very beginning each time, and you will get repetitive or wrong responses.

Firemangeorge is right - post those codes even though they are infrequent.

 

Actually there were only 3. I merged all of them together. It will make for tough reading but it is what it is.