SOLVED! No Crank On 2002 Trailblazer 4.2
- Thread starter ek02
- Start date
I cannot remember if the grounds were verified?? That ribbon connector carries the grounds to the BCM.
It truly is difficult to pin down an intermittent issue. A ground may very well test out fine when you test it but come and go in use.
gmcman
Member
- Dec 12, 2011
- 4,660
Did anything ever get spilled in the back seat? I doubt that with the cover installed that anything could enter the BCM but that's assuming the cover was in place.
Reason I ask, maybe just the camera, but it appears to have a residue in a few places around the ribbon connection.
I doubt there are any bad solder joints, but is there any way to check underneath the BCM for bad solder joints?
Maybe take some 000 steel wool to the pins where the ribbon connector attaches.
Reason I ask, maybe just the camera, but it appears to have a residue in a few places around the ribbon connection.
I doubt there are any bad solder joints, but is there any way to check underneath the BCM for bad solder joints?
Maybe take some 000 steel wool to the pins where the ribbon connector attaches.
The fuse box looks pristine on mine. I pulled the fuse box today and turned it over to get a look at the wiring and solder joints, but there are 3 covers that look like they are not removable. They look like the factory snapped them in with no way to release the 4 tabs on each cover without damaging them. The ground for the BCM is behind the B pillar cover and it looks perfect. Nothing was spilled on the ribbon connector. I can slide the lock on the ribbon connector and wiggle it while holding it down and get anything thats not working to come on. Either the pins are not making good contact or the ribbon connector has an invisible defect. When it starts and runs and all functions work perfectly, the security light comes on solid. Wiggle the connector and it goes off but then comes back on. Using contact cleaner on the ribbon and pins make it start and run perfect. I'll clean the pins when the ribbon connector arrives, but this TB was garaged kept for 8 years and driven by my wife's cousin. I bought it and have kept it in a carport. No kids ever rode in it.
Well that pic is MY trailblazer and it has no issues!! Theree is a bunch of what looks like dielectric grease on the slider lock mechanism.
gmcman
Member
- Dec 12, 2011
- 4,660
Ah, ok, I thought that may have been a pic of the OP's fusebox you were referencing.
Still fooling with this thing. I checked the ribbon connector with an ohm meter and it tested good. Tried a different ribbon connector and same issues. I can disconnect all wires from the BCM, reconnect' and after turning the key to start a few times it will start, run, and have all functions. It's not consistent. I may just be rebooting the BCM if that's possible. Checking all modules with the Tech II shows all active when it's running right. Then the security light comes on but it runs perfect and everything works. I can command the light off but it comes right back on. I checked all the grounds again. All look good. I won't be able to do much more until next week due to Tropical Storm or possible Hurricane Isaias heading toward S. Florida. I have used the Tech II enough now to refresh my memory. It works a lot better connected to the battery instead of the power plug in the dash.
Mooseman
Moderator
you can check the power status of the bcm with the techII... that will tell what's up... do it with key on / no engine running and then again with key on / engine running (however you get that to happen) and then again when you get the security light on ( are you referring to a "theft light" or "contents security light"?).
oops... I guess it is the same light but there are differences in system response, in contents security, horn and lights happen while with theft, no audible / visual alarm responses.
oops... I guess it is the same light but there are differences in system response, in contents security, horn and lights happen while with theft, no audible / visual alarm responses.
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OK, problem solved. Got a break in the weather and hooked up the Tech 2 when the truck would not start today. All modules could be pinged and activated. Went into the BMC and no communication. I could communicate when I had it running a few days ago. My gut feeling was that the BMC itself was the issue. I ordered a programmed BMC on E Bay for 145.00. The seller said the SDM ( air bag ) light would stay on and gave me a video on how to get the SDM module programmed to the BCM with the Tech 2. I sent him the VIN and a photo of the RPO's from the glove box door. I did the key relearn and it fired up, then did the SDM learn. I drove it around, got gas, and stopped and started it for most of the day. My only problem is one remote locks and unlocks the doors and sets the alarm with a horn beep. The other remote only locks and unlocks the doors, no horn beep. Both set off the panic alarm. Not a big issue. Edit: OK, both remotes now work properly. Thanks so much to everyone that replied and gave me suggestions. I learned a bunch form this experience. Intermittent problems are the worst for any Technician to solve. That was my biggest headache as a Fleet Manager and as a Technician. Never too old to learn, even at age 74. Here is the link if anyone needs a BCM. Edit: ( B065 is just the location in his warehouse )
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You guys have a wealth of knowledge about these great vehicles. Thanks again for all the replies, video's, and suggestions. I've driven it for 2 days now and all is well.