MT computer in an AT 94 ranger

[nightshift]

I think I'm getting hosed! I took my daughters 94 ranger, 4.0, automatic,
4WD to a local shop because it was running like crap and I didn't have time to mess with it. They replaced the ECU and MAF sensor.

Now it runs great, but I don't have overdrive and converter lockup. Smelling a rat, I pulled the computer. This vehicle is supposed to have a computer with the four-letter code LAGO. They put in a computer with the four-letter code HAGO. HAGO is for a 94 ranger, 4.0 manual trans.

The question is, would installing the HAGO (manual trans) computer in an auto trans truck cause the overdrive and lockup to not work? If so, can it be re-programmed to operate the overdive and lockup?

 

[SenorNoob]

Well, since both are computer controlled, I'd say yeah. It could make them not work. While reprogramming is possible it'd probably be easier and cheaper to change the computer.

If you're cheap and feeling lucky you might try swapping the memory chip from the auto ECU.

 

[enjr44]

If it were me, I'd take it back to the mechanic and raise some heck. He installed the wrong computer and he should put the correct one in. Simple as that since you have troubleshot the problem for them. A computer for a manual trans will not have the correct circuit board for an auto. It does not know that there is a torque converter in the truck, let alone lockup or overdrive.

Fyi, whenever I have work done by someone else, I pay with a credit card for this exact reason. You can go to the CC company and protest the charges if the supplier will not stand up(ripped you off). And they will help you straighten out the problem (they want you to continue using their card).

 

[nightshift]

Success!

I removed the ECU they put in there and installed the ECU that used to be in this Ranger. Lo-and-behold, now she runs well, and I have overdrive and lock-up again. The only code in there now is 176 (bank 2 running lean). That code has been there for a few years. I just ordered two OE-type O2 sensors from Rock Auto for about half the price of some of the big-name stores, and that should kill off the code 176.

I've left out a lot of unimportant details to shorten this tale a little. So to sum it up, it looks like an ECU for a manual trans vehicle will not work correctly in an auto trans vehicle. The engine seems to function OK, but the manual trans ECU will not be able to handle auto trans functions that are controlled by an ECU, and you will also get a code 528 for "clutch pedal position switch circuit failure".

Now I have to go dance with shop and get my money back for the wrong ECU they put in there. Too bad...I had such high hopes for these guys.