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My 98 tahoe has all the factory wiring still in place... when I set my new drivetrain in will I be able to re use the module that was unbolted from my stock 4L60E and retain my gear indicator light on the cluster?? I am going to leave the stock harness where it is and clip off all the plugs that are not needed, heatshrink the ends and tuck them away... I will be using a harness and PCM program from PSI for the new engine and trans
Good question. You will definitely need the module so the new PCM knows what gear the transmission is in. Without a wiring diagram, it would be hard to figure out how to make it work.
Your new PCM may have a wire that goes to the dash to make it work. Not sure though.
I am pretty sure the gear indicator will have nothing to do with the new harness, the PSI harness is stand alone... I was just wondering about the module on the side of the trans wether or not it goes thru the old pcm or straight to the wiring in the dash harness
You will need he neutral/shift switch for the LS PCM to control the transmission,I beleive the truck shift indicator wires need to be spliced onto your new harness.Do a search here for eliminating the old black box PCM,its just not needed anymore.
i just reworked a harness on an 02 and the small 4 pin plug is for the pcm and the other plug I think there was 6 wires was seperate because I removed it from my harness and I am gonna use my original gear indicator harness also. They ended up going to one of the other connectors that get cut off in the factory harness
The indicator light has nothing to do with my harness, the new harness I have is completely stand alone and has the trans harness with it as well, I just need to know how to get the gear indicator light in the dash to light up, I am still searching....
there are 2 plugs on it the 4 pin one is for the pcm and the other one is for the indicator lights and for the park neutral when i did my harness only the 4 pin one stayed the other one i took out so on my truck all i have to do is plug in the bigger of the 2 and that will run the indicator lights. whether the psi harnes includes the 4 pin plug i have no idea but its the bigger or the 2 that controls it so dont cut that one off
Thanks for the info, my reverse lights work but I still have no indicator light in the dash, the only plugs for the trans in the PSI harness for the trans were the VSS and the Main round plug... I might possibly have a faulty neutral safety switch or could the light in the cluster for the gear indicator be bad?
I would give PSI a call. They are very good at answering your questions.
I have to agree with you 100%, Jon has been very helpful with the few questions I have had during the install.....Quote:
Originally Posted by gagliano7
Pics and info once you get this figured out, please! Im at the same point, figuring out all the little stuff.
I'll be sure and post up when I figure it out, right now i've got it running and trying to figure out the AC,, I pinned all my wires for the AC from my stock harness into the new PCM and it does not work,, getting a little aggravated :sigh: