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View Full Version : 240sx 2003 escalade PCM 1mb question



devlmaycry
September 15th, 2011, 01:55 PM
Ok, had a thread on here a while back about my 240sx with LQ9/t56 swap, and finally made it back to the tuner today to try and get this whole tune thing lined out. From what I gathered the PCM still is flashed as the truck tune and thinks it's a 4l60e with all the tables and general settings adjusted for my setup.

It was falling on it's face over 4k, and I've have an intermittent pending p0332 (the bank 1 low voltage error). I replaced the knock sensors and it was still giving me the pending code. When I showed up today under WOT it wasn't switching to the PE tables, so it was leaning out real bad. I'm not sure what he had to do to finally get it lined out (I'm not a tuner), but as he was compairing a COS with the truck tune and discovered another COS in the background that only shows up when compairing another COS or something. He says he's seen similar stuff happen with PCM's that have been touched with like a diablo or one of those handheld tuners.

Anyways now there's an issue with the knock sensors not getting 5v from the PCM, but the scanner is still reading knock properly. At cruising it's not giving issues, but at WOT when it's supposed to go into PE it pulls max timing instantly due to the knock sensor issue. From what I've read this would presumably be from the PCM not seeing that 5v reference for circuit intergrity. He zeroed it out and it's not pulling timing now, and the fuel tables are lined out finally. However he would like to tune it right VS having to trick it to get it to do what it's supposed to. I'm running out of ideas about what's up with this thing. As far as how it drives now, it seems to drive 10x better than it did before. It pulls good through the RPMS, and doesn't seem to be falling flat after 4k. However now I have a near constant pending bank 1 and bank 2 low voltage pending and sometimes on CEL.

Once I got home I dug out the volt meter and the harness checks out. The KS's are new, but the PCM doesn't seem to be out putting that 5v signal

So, as I was searching for a replacement PCM I found out the 2004 model 12586243 PCM came with a vette tune for 6 speeds which would be the closest stock tune to my setup and also has the same pinout. Can EFIlive do a complete reflash to the 12586243 tune or with my PCM would it be best to just grab a used 12586243? The tuner seems to lean towards just putting the vette PCM in it and going from there.

As far as posting the tune I will have to see if he can email it to me. At this point he probably wouldn't be opposed to it just to figure out what's up with this thing.

GMPX
September 15th, 2011, 02:24 PM
When EFILive does a full flash on an LS1 PCM it will write everything. However, I am sure there is some differences between some 1Mb PCM's, eg, some cannot be used in certain models because they are missing some parts internally.