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Need help, bunch of problems with my trailblazer.

7K views 39 replies 15 participants last post by  MrSmithsTB 
#1 · (Edited by Moderator)
Well, about two weeks ago all I did was change my headlights. I put some xenon lights (hyper white) and I had no issues.

I was driving and I noticed all my lights were off. I get home, nothing works. No lights, dash lights, interior lights, and rear windows.

I've been without a car now for two weeks, and its been at my mechanic shop for that long. We cannot find the problem.

I cleared the codes, and this code "U1000" keeps coming up. There is no serial communication.



Please, and thanks trailvoy members!
 
#2 ·
okay lets see check the ignition switch, see if your getting power to and from it look at the fuse panel in the back, check eveeryhitg there and check the 12v pos. cable comming form the batt. going to that. check the bcm connections too start there....
 
#8 ·
Even with a bad megafuse the truck should start. Smells like ignition switch.

2 weeks? :eek:

When you say no lights, did you mean no headlights, either? What if anything in the vehicle DID work? Gauges?

Anyway, the PCM (combined ECM and TCM in the I6) is on the driver's side of the engine. The BCM is just forward of the rear fuse block.
The truck started before today, my mechanic told me to leave the jumper on it for 10 minutes with the ignition on to see if that's the problem.

Okay, we found the problem, and it is the part infront of the fuse block under the rear seat.

I called a few part stores and they are telling me that is not the bcm.

Yes, no highs, no dash lights, some gauges work, no locks, no rear windows, and no interior lights.
 
#7 ·
Even with a bad megafuse the truck should start. Smells like ignition switch.

2 weeks? :eek:

When you say no lights, did you mean no headlights, either? What if anything in the vehicle DID work? Gauges?

Anyway, the PCM (combined ECM and TCM in the I6) is on the driver's side of the engine. The BCM is just forward of the rear fuse block.
 
#9 ·
How are you sure that's the problem? Swap with another trailvoy?

Anyway, if you buy another BCM off Ebay or the dealer, it will have to be configured by the dealer and their tech tool to install the VIN and your list of options. Unless your mechanic has access to the GM tech tool and the latest flash updates.

The parts stores are wrong, I think. Item 3 is the BCM.

 
#17 ·
That's not the problem, we found the problem.

We're trying to bypass it, and re-run a wire to the 6th pin on the top of the BCM.

If not, I found one for $50 my cost. (BCM)

Something odd happened though, as soon as we put power to the connector, one line down the green wires turned black instantly, but still has power..

I'm not very good at describing, sorry.
 
#19 ·
That's not the problem, we found the problem.

We're trying to bypass it, and re-run a wire to the 6th pin on the top of the BCM.
Something odd happened though, as soon as we put power to the connector, one line down the green wires turned black instantly, but still has power..

I'm not very good at describing, sorry.
What, no fire and smoke?????:(:(:(
 
#22 ·
You have someone jumping wires and shorting and burning things out. At this point you should take it to Chevy and find out what has been burning out and how to fix it. OK? This is help. Next to getting a Priest and doing an Exorcism!

Maybe this needs to be closed!!!!:crazy::crazy: (two in one day might be a new record!)
 
#24 ·
in all honesty were trying to help you out but jumping wires on a bcm is no good.... and your going to have to bring it to chevy anyways to get it reprogramed to work with your truck so you may jsut want to bring it there now and save yourself some headaches... your not gonna be a happy camper if thats not your solution...
 
#27 ·
Ok jbizzle, you have a lot of good people pissed at you. Good people, who know their stuff and enjoy helping people on this site.

You need to listen to them and to me.

But, first things first:

Who ever can help me I would do anything for you (including sexual favors) :p
I'm a guy, and if you are, we can drop this promise right now, but if your not, we can talk later :laugh::laugh:


As soon as we put power to one of the little connectors, the lights come on, dash comes on, and car starts.
One of the connectors going into the BCM (on the top)
The BCM is a computer.......... It receives signals, from the driver and other parts of the vehicle, and responds to this input. Responding to this input usually means producing an output to operate things, like lights.

We are trying to tell you, that you are bypassing the necessary input and probably f**king up the BCM. You didn't need a new BCM when you logged on here, but you probably do now.

Now, let me make one other thing abundantly clear. You can not trouble shoot a trailblazer with a test lamp. YOU NEED A DIGITAL VOLT-METER (and most times, a very expensive piece of test equipment, only available in a GM shop)

When your ready, let us have the requested information and we will do whatever we can to help. :thumbsup:
 
#28 ·
I agree.. take it to a dealership and have them do a full deep diagnostic test on the BCM and its related counterparts..


bypassing the BCM and charring wires is a sure fire way to have a cookout at your house with your truck as the grille..

apparently your mechanic is an idiot and has no clue what he is doing if he is trying to bypass a key part of the system.. :nono:



So we have told you how to handle this THE RIGHT WAY.. but if you choose to ignore our expertise then I dont know what to tell ya
 
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