Liftgate Control Module Swap-out

[KEMiller]

I hope you guys can tolerate one more thread about liftgate control modules...

I have a 2002 Trailblazer with 135k on it. At different times over the years, I lost the rear wiper and rear dofogger, but everything else works. Fuses are good, wiring through the boot looks good after two looks. I dropped $80 to get the local dealer to do some diagnosis, and for what it's worth, they told me the wiper failure is due to a bad motor, and the defogger failure is due to a bad LCM.

Now for the question...is it imperative that the LCM part number match exactly? I've read several posts on this and other forums about successful plug-and-play using salvaged modules, but it seems like nearly every module available has a different P/N. One seller on eBay tells me that the model year is not important...it's all about the P/N.

Any thoughts on that? I appreciate the help. I've already learned a lot.
KEM

 

[Gevans17]

I hope you guys can tolerate one more thread about liftgate control modules...

I have a 2002 Trailblazer with 135k on it. At different times over the years, I lost the rear wiper and rear dofogger, but everything else works. Fuses are good, wiring through the boot looks good after two looks. I dropped $80 to get the local dealer to do some diagnosis, and for what it's worth, they told me the wiper failure is due to a bad motor, and the defogger failure is due to a bad LCM.

Now for the question...is it imperative that the LCM part number match exactly? I've read several posts on this and other forums about successful plug-and-play using salvaged modules, but it seems like nearly every module available has a different P/N. One seller on eBay tells me that the model year is not important...it's all about the P/N.


Any thoughts on that? I appreciate the help. I've already learned a lot.
KEM

I used a used Liftgate module in my 2002 for a much newer Trailblazer. Worked great
Numbers didn't match. Everthing worked except key fobs, and they went out a long toime before everything in the rear hatch died.

 

[triz]

Does your hatch lock with the remote. You might just need a new latch. Mine broke in two and my wiper would not work either till I replaced the latch. It would show gate ajar. Got one from a scrapyard and its all good now.

 

[Gevans17]

Does your hatch lock with the remote. You might just need a new latch. Mine broke in two and my wiper would not work either till I replaced the latch. It would show gate ajar. Got one from a scrapyard and its all good now.

Everything locks with the power lock switch on the drivers door. Nothing locks with the key Fobs. Its the fobs and I can live without.

 

[KEMiller]

I hope you guys can tolerate one more thread about liftgate control modules...

I have a 2002 Trailblazer with 135k on it. At different times over the years, I lost the rear wiper and rear dofogger, but everything else works. Fuses are good, wiring through the boot looks good after two looks. I dropped $80 to get the local dealer to do some diagnosis, and for what it's worth, they told me the wiper failure is due to a bad motor, and the defogger failure is due to a bad LCM.

Now for the question...is it imperative that the LCM part number match exactly? I've read several posts on this and other forums about successful plug-and-play using salvaged modules, but it seems like nearly every module available has a different P/N. One seller on eBay tells me that the model year is not important...it's all about the P/N.

Any thoughts on that? I appreciate the help. I've already learned a lot.
KEM

An update on my first post...

I bought a replacement lift gate module on eBay that was an exact P/N match and that fixed my defogger.

I bought a replacement wiper motor on eBay, and in the process of replacing it, decided to try my old one one last time, and it fired right up. Was it the module? Don't know. Was it a wiring short? Maybe. Because after it worked, I reinstalled the whole smash and it quit working again. Took the trim panels back off, fiddled around a bit and now it's working. I'm not convinced it's the wiring from the body to the lift gate, but maybe. Each wire looks intact, but maybe the conductor within is shot. I'll keep playing.