pcmhacking.net

Hey all,

About a year ago I purchased a VX LS1 Berlina and have had very limited success connecting and logging any data from the PCM due to Holden's decision not to fully implement OBD2 compliance, instead going only part way and as a result nothing short of a genuine Tech 2 is able to communicate completely with it.

It just occurred to me that it would be great if the PCM binary could be upgraded to a later, full OBD2 compliant binary from later model LS1, and then hopefully the software packages I have tried in the past will finally work.

So my question is, would it be possible to simply upgrade the binary in my PCM to a later binary and have full OBD2 compliance?

Thanks.

The ls1 pcm is vpw which is obd 2. Most the rest of the car is aldl (obd 1.5). There is a PIM module which converts some of the vpw traffic to aldl and vice versa so eg the dash can work. You cant change this without a major hardware and software re-engineering task which will not be worth it, even if you were prepared to try it. Im not sure what software your talking about but if you want to log the pcm off the shelf obd 2 stuff will be fine for SAE pids and some tools know about the GM engineering ones too providing more data than whats defined by the SAE. If you wish to configure srs abs or anything else its all proprietry and tech2 is the tool for the job.

Thanks antus,

Not what I wanted to hear, but kind of figured that may be the case.

Does this also mean that if I wanted to replace the original VX LS1 engine with a lower km later model LS1, say from a VZ, that I could not use the the VZ PCM as it would not "talk" to the other systems?

Thanks.

Chuff

thats a complicated question... the VZ is still ALDL on all the body modules same as the earlier ones. they didnt go full on CAN OBD2 until the VE. the 5.7L VZ engine still uses almost the same pcm as the earlier ones so it would probably work in a VX without much trouble. the 6.0L VZ engine has a different pcm and a different PIM as its not VPW like the 5.7 but CAN based comms. im not sure a VZ PIM will wokr in a VX so worst case you dont hook up any comms, then picture it like converting the engine into anything for example... the engien will run fine with anti theft off, but its the features in the body that wont work. eg: Anti theft, low speed fan, check engine light on dash, oil warning light, coolant temp.

Was it vx or vz that got the electronic throttlebody? If you move from without to with you'll need the 1mbyte pcm with the green connector instead of red to run the OS that handles electronic throttle. But it would work.

electronic throttle wasnt till VZ