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Discussion Starter · #1 ·
My wife and I stopped for a meeting this afternoon. We were away from her ‘07 Envoy about 20 minutes. Everything was normal before we stopped. As soon as she started driving we heard the power door locks activate several times. Pretty much every little bump all four doors unlocked. Occasionally only one or two would unlock. A short time after we took off I noticed the radio was blank. I power cycled it and it started playing but screen was still blank. I spun the tuning knob a few times and power cycled again and the screen started working as normal. The locks continued cycling at bumps. They would always unlock. We could lock them but next bump they’d unlock again. We’ve never had any issues like this before. Only possible thing is we just got it back last Friday from the body shop. They repaired damage from a right front impact. It wasn’t that bad. I don’t think they removed the passenger door. Grill, right fender and bumper cover were the bulk of the repairs.
Thoughts?

Thanks, Matt
 

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Occasionally only one or two would unlock. A
When it was only one or two, which were they? Fronts or rears? Front doors are unlocked by their respective modules, driver or passengers. Rear doors are unlocked by the BCM which is under the rear seat with the fuseblock there.

The BCM also is involved with the radio operations. So there is a common item between the door locks and radio.

The radio on/off button really does not turn power on or off as the radio always has power even when the key is out. It is the BCM that sends a message to the radio when the key is turned on telling the radio it's OK to operate if the on/off button is pressed.
 

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Discussion Starter · #4 ·
Revisiting this post. The door locks and radio quit having issues a couple days after my last post on the subject. Everything has been quiet until this past week. My wife was driving home one evening and the headlights cut out. She drove it the rest of the way home after playing with the switch and shutting it off a couple times. The lights didn’t come back on so she hit the flashers and made it the few miles to the house. Next day they’re working again. She avoided driving at night for a few days but Friday she was out later than planned and they quit again. She played with the switch a bit and they stayed on. They quit again Saturday evening but came back by themselves.
I don’t know if the lights are controlled through the junction box under the back seat but the way they are behaving, it’s a bit like the door locks and radio issue. I unplugged and reseated all the connections at that junction box. None appeared poorly seated. I’m going to give it another couple evenings and see if it is any better. If it still is screwing up, any ideas before I take it in. I really hate taking a vehicle in when it is an intermittent problem!

Thanks, Matt
 

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I unplugged and reseated all the connections at that junction box

The vertically mounted device alongside the rear fuseblock is the BCM, Body Control Module. This module is the controller of all the systems you have had issues with. It has numerous power supply lines to it and at least two ground circuits.

When you disconnected and reseated "all connections" here did you remove and inspect both ends of the green (mostly) flat ribbon cable??
 

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Discussion Starter · #6 ·
The vertically mounted device alongside the rear fuseblock is the BCM, Body Control Module. This module is the controller of all the systems you have had issues with. It has numerous power supply lines to it and at least two ground circuits.

When you disconnected and reseated "all connections" here did you remove and inspect both ends of the green (mostly) flat ribbon cable??
I only disconnected the end that plugs into the BCM. The flat cable was in the way a bit and I couldn’t clearly see how to release the other end of the flat cable. I kinda wiggled it a bit but didn’t want to damage it if I wasn’t using the correct tabs to release it.
Matt
 

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There is a tab that pushes down just a bit to unlock the gray slider that locks in the larger end of that flat cable. I bring that up because it has been the issue for a few folks. Let's see if I can grab a picture...or several... The first shows the locking tab and the final shows the gray slider in the fully released position. I have seen owners with burnt connections here as well as one that looked like some unknown goop got spilled on it.

Automotive tire Automotive lighting Auto part Motor vehicle Automotive exterior


Automotive tire Hood Automotive lighting Motor vehicle Bumper


Motor vehicle Hood Bumper Automotive exterior Finger
 

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Discussion Starter · #8 ·
I’m glad I didn’t attempt to unplug that one before seeing your pics! I did just unplug and reseat it though. I might take a short drive in a few minutes to see if it’s improved at all.

Thanks!
 

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I had the same problem with the headlights, turned out to be relay #46 under the hood. PN 15016745. Have to get it from Amazon, discontinued at dealer.
As far as the door locks go, don't know, maybe a bad ground?
 

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I'm fixing the same problem on an older Astro (not my wife's) that beside the bumpy road door lock firing, when you get out of the vehicle and close the driver's door, ALL the door locks cycle repeatedly for a few moments.

I found the wires in the bellows between the A-pillar and the door hinge area were all cracked and shorting each other out.

I'm still fixing it as it's hard to work inside that left p-brake kick panel because the access hole doesn't line up with the actual bellows base --- but I'm on it between snowflakes ... in my driveway .... outside.
 

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Discussion Starter · #12 ·
Wife and I got caught out late tonight. Lights went out after a few minutes. Tried tapping on the 46 relay and they came back on. Another few minutes down the road they went out again. I tried swapping relays with #45 but they wouldn’t come on at all. Swapped back to the original relay and they came back on after tapping on it again. Only lasted a mile or so.
I’m afraid it’s gonna have to make a trip to the repair shop since I have serious doubts it is the relay. I’m thinking there may be a short somewhere that is causing it to trip. I have a new relay coming in tomorrow and I’ll try it but I really don’t think it is the problem.

Matt
 

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A "short" - if you think about it - is a short or incorrect pathway to ground - uncontrolled except possibly for a fuse or an unprotected wire that cannot survive carrying that much load/current/Amperage.

(NOTE ---> we don't usually test for Voltage because you can have Volts enough to swing a meter or even turn on a test light, but it won't do what it's intended to do when you put the beans* to it)

*BEANS is a complicated technical term.​

So-o-o ----- if a true short was involved, you'd have blown fuses or smoking wires or a melted/melting device somewhere.

Shockingly (and I was amazed when I found this out) a relay that was working in one position, may NOT want to work in another!

Yeah! Crazy, huh?

How do I know this crazy stuff? I bought a relay tester and it found not just a few that were questionable, one that was totally bad and another that was dying a slow yet ignoble death. Yet they were all working in their respective positions.

It's hard to claim a repair if you change out a relay that seemed to be working just fine - and that's between you and your customer and I wish you well when you try to explain that they need something that ain't broken.

But I am living proof of that condition.
 
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