85irocinjected

I have searched and cant find anything. maybe Im not putting the correct search terms in or something...anyhow...

I have a 99 4.3 in a jeep and its all wired and I can read from the pcm but it wont let me write. Im trying to disable vats. Is there something special I have to do to write to the pcm? It timeouts at Erasing PCM and fails everytime. Ive never had this issue with any other motor but this is the first 4.3. I noticed there are two Serial data lines in the black connector, one being pin 11 and the other 14 I believe. I have tried both seperate and both together. Someone please help. Also can I use a vats bypass box on this computer like on f-body computers or not? If so which wire do I need to attach it to?

Thanks.

oange ss

iTrader: (50)

how do you have your ALDC wired ? Kinda sounds like a software problem if you can read , you should be able to write, what software are you using ? The PCM your using should be the same as Gen 3 V8 equipped vehicles.

85irocinjected

The pcm is from a S10 blazer and has 4 plugs (red, white, black, blue) instead of the 2 (red, blue) like the normal Gen3 pcms. Im using the newest hptuner software downloaded off there site yesterday. I have never had any issues like this before.

The ALDL I have the 2 grounds attached to the neg. side of the bat. the orange to the positive side and the purple to the data wire from the pcm. There is a tan wire on the ALDL also but I didnt hook that up to anything. Like I said there are 2 data wires and no matter how I hook those up I can read the pcm but can't write to it.

oange ss

iTrader: (50)

is pin #11 on the black connector 1 of the VPW signals ?

85irocinjected

pin 11 is one of the class 3 serial data lines as is pin 14. They both allow me to read the entire pcm just not do any kind of write to the pcm

85irocinjected

Ahhh! This is so irratating! Same problem and here is what we have done:

Got a NEW computer from the same year/model vehicle to try
Got a NEW laptop with all the updated drivers and software from HPTuners
Got a NEW VCM Suite from HPTuners (friend bought the setup aswell)

Still having the same problem we can read the tune from the computer but cant write to it. Get the same error about a timeout on erasing vcm. Any help please.. Does somebody have a wiring schematic to a 1999-2000 s10 with a pcm with the 4 plugs so that I can compare it with the ones I have just to 100th check the wiring again..I can't figure this out and its driving me CRAZY

85irocinjected

Apparently the 16263494 pcm has problems with hptuners where it can be read from but not written to so we just converted over to the 0411 pcm and it works great. In my opinion AVOID Service #16263494 pcms so you dont have any kind of issues.