99-02 pcm battery light ****update**
10-27-2004, 05:24 PM
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99-02 pcm battery light ****update**11-12-04***
First off for the new guys I have a 02 Nelson Tuned pcm in my 99 Step side.
Bottom line without getting into it, I did this because it runs alot better than the 99 ever could.
The only problem I have is the flashing battery light and dtc code "Generator Terminal F circuit"
Looking at the wiring schematics between the 99 and 02 the only differance I found was an additional wire from the pcm Red terminal #52 to the alternator.
Terminal 52 is not used on the 99 pcm.
Well thanks to Allen I got a pcm clip and finally added the wire to terminal 52.
I ran it up to the alternator and now I'm only waiting for a new plug (02 plug on order) to plug in the alternator. The 99 doen't have a slot for it so I can't just add the wire to it.
If that doesn't cure it there may be a missing wire in the alternator itself. i tried taking the black plastic off the back but couldn't see if there was two wires or not. I ordered a GM 145a alt because I needed one anyway so that may have the upgraded wiring.
The next step after that is scaning the nelson pcm and picking up the vin and ordering a 02 bcm. the dealer is going to have to flash the new bcm with the vin from my 02 pcm.
Should know in the next few days when the plug comes in.
Bottom line without getting into it, I did this because it runs alot better than the 99 ever could.
The only problem I have is the flashing battery light and dtc code "Generator Terminal F circuit"
Looking at the wiring schematics between the 99 and 02 the only differance I found was an additional wire from the pcm Red terminal #52 to the alternator.
Terminal 52 is not used on the 99 pcm.
Well thanks to Allen I got a pcm clip and finally added the wire to terminal 52.
I ran it up to the alternator and now I'm only waiting for a new plug (02 plug on order) to plug in the alternator. The 99 doen't have a slot for it so I can't just add the wire to it.
If that doesn't cure it there may be a missing wire in the alternator itself. i tried taking the black plastic off the back but couldn't see if there was two wires or not. I ordered a GM 145a alt because I needed one anyway so that may have the upgraded wiring.
The next step after that is scaning the nelson pcm and picking up the vin and ordering a 02 bcm. the dealer is going to have to flash the new bcm with the vin from my 02 pcm.
Should know in the next few days when the plug comes in.
10-27-2004, 06:50 PM
#3
I definitely want to know! I'm sure 99silver5.3 is interested too. Funny you should start this thread today...check this out: https://ls1tech.com/forums/showthread.php?t=231783
Good Timing...no pun intended.
Good Timing...no pun intended.
10-28-2004, 12:40 AM
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Hey Creede, thanks for all the good info, I'm also trying this on my father in laws 99GMC, I'll keep you posted.
Let me know if you need that vin,
later,
allen
Let me know if you need that vin,
later,
allen
11-12-2004, 11:45 PM
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I purchased an alternator clip from the dealer for an 02 alternator.
Part # 15306329 $14
It came with two wires coming out of it. I wired one to the stock 99 brown wire and the second to the new wire I had run from the pcm.Plugged it all in and No more flashing battery light
Sorry the update took so long i havn't had much time lately.
So it looks like for now to get rid of the light you have to run a wire from terminal 52 (red) to the terminal next to the factory wire on the alternator harness.
Thanks allen for the clip
Part # 15306329 $14
It came with two wires coming out of it. I wired one to the stock 99 brown wire and the second to the new wire I had run from the pcm.Plugged it all in and No more flashing battery light
Sorry the update took so long i havn't had much time lately.
So it looks like for now to get rid of the light you have to run a wire from terminal 52 (red) to the terminal next to the factory wire on the alternator harness.
Thanks allen for the clip
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11-15-2004, 08:40 PM
#9
Does the alternator need to be replaced, or will this fix work with the original alternator also? And why does the BCM have to be replaced with one from an 02 with a matching vin also? Compatability issues? This may be the route that I go, and I'd like to get my plan all figured out before I do it. Here's a rough draft parts list, feel free to make corrections and additions:
1.) Alternator Clip Part # 15306329 $14
2.) Terminal End for the PCM
3.) Wire
4.) Munchos chips
5.) Bud Bottles (try not to knock them off of the bench)
Oh yea, gotta get my hands on an 02 PCM that is compatible with my truck, and start playing with it. While Bryan at PCMforLess is trying to work out a custom PCM for me, maybe I can get my hands on some parts and do a little tweaking in the mean time
Anybody know of any decent junkyards in North Jersey?
1.) Alternator Clip Part # 15306329 $14
2.) Terminal End for the PCM
3.) Wire
4.) Munchos chips
5.) Bud Bottles (try not to knock them off of the bench)
Oh yea, gotta get my hands on an 02 PCM that is compatible with my truck, and start playing with it. While Bryan at PCMforLess is trying to work out a custom PCM for me, maybe I can get my hands on some parts and do a little tweaking in the mean time
Anybody know of any decent junkyards in North Jersey?
