As I was reassembling everything I found a used ECM from a 99 Ram pickup that should do the trick so I sent it off for reprogramming. Tactical error on my part . My research had shown that any ECM from any V-8 as long as it was the same year would run the Dakota, though I would have a Check Engine light for VIN mismatch. So what I did was send the ECM to a programmer to recode the VIN and do one of his stock tunes. Cost me $400.
ECM arrives, check
Everything reinstalled, check
All relevant sensors transferred from the old engine, check
Wiring harness plugged in and doublechecked, check
All fluids topped off, check
Fingers crossed, check
Time for the first start. Hold breath and turn the key, she fires right up and purrs like a kitten! Score! After a little warmup and leak check, time for the test drive. I made it down the street and around the corner before coming back to adjust the TV cable. A few more jaunts down the street for fine tuning and she's shifting normally. Time for a longer test drive! Now things go slightly south - when I could finally get above 30 mph (where I live it's 3 miles of 30 before getting to a road with a higher speed) 1st, 2nd and 3rd shifts are normal but I'm not getting OD or converter lockup. Hmmmm. Had it before but not now. Sidenote - this era Dodge transmissions shift hydraulically through 3rd gear and electronically into OD and TCC lockup.
Back to the garage to recheck all the wiring and reset the trans harness. Back for another test drive, no change. But on a good note the new junkyard engine is singing sweetly! Time for some research. Since I was still using the 42RE trans I thought maybe there was a difference in the inputs and the tune was for a 46RE. But for now I'm not too worried, the answer will eventually turn up.
Fast forward a few weeks, no answer! Still no OD or Converter lockup. No a big deal in town but zipping along at 3000+ RPM at highway speeds gets annoying. I had not found any onboard faults and had done some troubleshooting, checking voltages, etc., at the trans connector, still no dice. Next step, call the tuner. This is where even now my heart rate goes ballistic. When I sent the ECM in I filled out the tuning sheet he provides and on it I had noted that I was going to use the 42RE until I acquired a 46RE. When I called him to try to find some help and told him what was going on, he basically blamed me for not putting the 46 in right away. Whaa?? Essentially I got no answer from him. Double Hmmmm.
I found a local guy who, though could not tune the ECM, he could hook up his scanner and check things out. We went for several test drives and discovered that basically, the transmission was doing it's thing correctly but was getting no signals from the ECM. Still not fixed but slowly the boxes are filling in. I tried several more times to connect with the tuner but got nowhere several more times . Then I had a brainstorm - on the next salvage yard expedition, pick up another ECM and try it!
New ECM hooked up, all transmission functions normal! Yay! Except I have a bum ECM that I spent lots of money on. Now it's time to investigate that. I had found on the interwebs some writeups describing my very problem - seems it is a fairly common failure point on this era Dodge ECMs. Maybe I sent him a bad ECM and he either didn't function check it or can't function check it. So I call him - again - and get the runaround - again! Triple Hmmmm.
Step 4 (or 5 or 11 at this point). My local guy recommended another semi-local shop who could do ECM tuning, so I stopped in there and asked if they could put the bad ECM on the bench and check it out for me, which they did. Guess what they found? The ECM is fine but the tune was for a manual trans! He had written out (or not included) any AT functions! So another call - and he flatly denies it, says it's my fault and I should be running a 46RE since there is no tune for a 42RE, Has no answer when I confront him about there being no AT function in his tune. Then he hangs up on me. Guess who will not be getting any more business from me, nor any referrals, plus a bad reference to anybody looking for this kind of work. Sadly, not much else I can do.
But now I have a fabulous running Dakota! And my salvage yard expedition yielded many more goodies, but that's for the next installment.
Cheers,
Mark