MikeH

Didn't realize the PCM would need reprogramming also. I'll keep them as is for now...just as a backup. Thanks

Sort of thought something like that was going on. Couldn't quite figure out what I had done to get the correct odometer reading after installing both computers. I take it that a scan with the correct reader would still show I'm using an ECM with the wrong VIN#? And if that's so a re-flash of the donor ECM would correct the issue...right. Do I need to worry about any of this? I plan on keeping the rig so don't really care what the info ECM is holding. The only problem I can see is during emissions testing the donor VIN would pop up...right. As the donor ECM/PCM were purchased for emergency use only (I've decided to keep the OEM computers on the rig until one fails) I can address a re-flash when the time comes.

Still wondering what stores the odometer reading? Is it the ECM, the PCM or a collaboration of both? My rig showed the correct odometer reading after the install but I did put on the donor PCM with my OEM ECM first. Don't know if that mattered but I got the correct reading after installing both units and driving for ~30 minutes. Anyone know for sure which computer actually stores and keeps track of the odometer?

Good news! Hooked up the PCM which worked fine. Didn't think it would be a problem. Then hooked up the ECM. Before starting anything I drained the ECM to ground to clear out any codes or memory. I've used this tactic before to turn off a pesky engine light or codes. It drains all the capacitors of energy so the ECM will have to learn your engine & APPS settings after it starts. Anyway, started the truck and drove around for 30 minutes or so and all's well. I was holding my breath on the ECM but it turned out OK. I think the trick is to find a donor rig that is absolutely identical to yours (make, model, year, engine, tranny...everything). After grounding out the ECM (google...lots of info) it should learn your truck config and be good to go.

Been doing a little research and it looks like the ECM will need to be flashed with my VIN#. The PCM should be fine as is. Just wondering if a local Dodge dealer would do the re-flash or not. I'm guessing not but...

" VIN problems when mixing them" Not sure what you mean by "mixing them". The donor rig was identical to mine (2002 Ram/Cummins 2500 HO w/six speed tran). But...this is my first shot at this too which is the reason for my post. I'm hoping it's a straight swap and the ECM doesn't need a re-flash etc.

I put a relay on my intank pump (completely hybrid fuel system...don't ask) and fused it with a 10 amp. Hasn't popped it yet so I would guess something under that (5 amps maybe?).

Just purchased a used ECM + PCM for my pickup. We travel a lot (including Mexico) and I want to keep a few critical spare parts on hand just in case. The donor rig was a perfect match (2002 Dodge Cummins HO six speed) for my truck and the price was right so I jumped on it. I'm assuming the ECM especially does not need to be re-flashed or anything and will be a plug and play item. Both computers are OEM off a totaled rig (121K miles....front end smashed but engine compartment looked fine). Guess I'm taking a little bit of a chance on this purchase but both computers looked great and the truck was running (obviously) at the time so they worked right up to the accident. Anything special I need to know about replacing the computers? I'm planning on pulling both of mine (they work fine) and keep them as my spares. I'll run these replacements until one fails. TNX....Mike