Thread: Wiring Diagrams and Pinouts available for download here

GM Wiring Diagrams and Pinouts

-ryan

Very nice. A lot of good information there. Thank you for posting that up.

Nice link. Thanks!

I can't find anything for 04+ GP PCM's CAN leads... or any other leads for that matter! Does anyone have the diagrams for the stock 2004 PCM wiring? From what I've studied about the 6T70E, it picks up the CAN data from the ECM in stock applications, and the on-board TCM controls it. If our 8th gen Grand Prixs use the same CANBUS as later cars, then I'm one step closer to figuring out how to adapt the 6-speed auto... unless that's already been sorted, that is!

(BTW: I've been Searching-including on this forum-till the cows came home for the diagrams; nada on the 3800 PCM, though I got something more useful on the gearbox!)

The 3800 was never used with a 6-speed automatic from the factory. And even though GM switched the 3800 over to using the new PCM architecture (CAN bus style looking computer module) starting in 2004 with the 3800 Series 3 engines, these PCMs were never connected to the CAN bus and thus have no GM Hi Speed LAN data capability (at least that I'm aware of). In other words, you'll never be able to run a GM 6-speed auto transmission with a factory GM 3800 PCM. You'll either need to switch to a different ECM to run the 3800 or you'll have to get an aftermarket TCM to run the 6-speed auto trans.

Is there enough demand for a 3800/6t7* swap to make a bespoke hybrid harness with a G6 ECM viable?

Good news: www.powertraincontrolsolutions.com has a stand-alone TCM that'll integrate the 6T7* to older cars, including the 3800. Bad news: it's still in development and not yet ready for sale! But at least there is a solution being worked on! (The module is TCM 2650, by the way)