Yes ... The BCM is grounded at the same point as the DDM, G302 on the lower left B pillar. A single wire runs from that ground point to the rear fuse block. It splits there and runs up through the rear fuseblock through that green flat ribbon cable at tracks A11 and B11. Inside the BCM circuit board these two tracks are rejoined/soldered together. They ran two tracks only to distribute the load carried by the two tracks.
SOLVED! DDM, PDM and keyless entry fob not working after a work done on the truck
- Thread starter ghost_leader07
- Start date
Yes ... The BCM is grounded at the same point as the DDM, G302 on the lower left B pillar. A single wire runs from that ground point to the rear fuse block. It splits there and runs up through the rear fuseblock through that green flat ribbon cable at tracks A11 and B11. Inside the BCM circuit board these two tracks are rejoined/soldered together. They ran two tracks only to distribute the load carried by the two tracks.
ghost_leader07
Member
Ok, I'm getting my friend's obd2 scanner maybe tomorrow or by Friday and I'll do the check for the communication wire as well, i believe the scanner can do actuation tests as well as reading all modules, I'm hoping it can help with figuring out the issue.
Look for a scantool test of the communications system. On a Tech 2 there is a test that will show a list of the modules and whether or not they are alive on the network.
With that Bluetooth OBD2 adapter ($14) there is a way to actually see the replies from the modules instead of just a yes/no type of display that a Tech 2 or similar scantool gives.
ghost_leader07
Member
Ok I'll look for that.
If a cheap obd2 adapter can do that, I'm pretty sure a more advanced one can show it as well, the one my friend's have it's a not fancy scanner it's actually a Bluetooth obd2 adapter with somewhat professional diagnostic features plus it's the only scanner that i tested and was able to communicate with ECU and rest of the modules, the cheaper ones weren't able to connect at all.
There are free manuals available here on GMTNation that include wiring diagrams. These can be difficult to find stuff in there sometimes.
There is also the website linked below that has free manuals both online and for download. This site is easily navigated to find what you are looking for once you get the hang of it.
Free Car Service Manuals from Operation CHARM — No strings attached!
Operation CHARM provides completely free repair/service/workshop manuals for over 50,000 models of cars and trucks manufactured 1982-2013. No sign-up or paywall.
charm.li
In this link below I have navigated to the 2004 Body Control Module wiring diagram.
Body Control Systems — 2004 Chevrolet TrailBlazer 4WD L6-4.2L VIN S Service Manual | Operation CHARM
Detailed repair manual for the 2004 Chevrolet TrailBlazer 4WD L6-4.2L VIN S.
charm.li
ghost_leader07
Member
Thanks for including these manuals however I'm not savvy enough to understand these very well so I'd need your help with it, thank you again for sparing the time to help me through this.
ghost_leader07
Member
@TJBaker57 Thank you very much i was able to reselove my issue following the comuntaction wire you mentioned (Dark-Blue/White) down to a big blue plug that wasn't fully locked once it was secured everything was back to working order! again big thanks my guy!
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ghost_leader07
Member