I want to put EFI on my truck and I have run into a good candidate donor truck. Only difference is mine is a standard transmission. Will an ECM from an automatic work fine?

I don't think it will be an issue but I figured id check first.

Thanks

 

It will whine about the not getting the inputs it expects from the trans, and turn on the check engine lite, but, that's about it. What year is your truck?

 

1988. There is a 1995 Dakota in the scraper with everything I need to do that swap.

Maybe I can somehow delete the sensors for the automatic transmission

 

95 PCM isn't flash programmable, but, you should be able to find one for a 5.2 and manual trans.

 

Do remember, the EFI on the 1995 Magnum won't fit a 1988 TBI.

Unless you're also swapping the motor AND all the wiring.

Including in the cab, and the steering column.

RwP

 

i was thinking along the lines of tricking the ecm into thinking the transmission is there using a resistor or short (if it’s a switch of some sort). If the in dash wiring differs, couldn’t I modify the harness I got from the scrapper to reflect those differences? I can’t possibly imagine what kind of differences the fuel injection version and Tbi version are. The interiors are almost identical.

i have a fresh rebuilt 3.9 magnum. Currently cleaning dirt and sludge off intake, wiring harness and accessory brackets.

 

Dude.

There's nothing the SAME between the 1988 TBI LA motor and the 1995 EFI Magnum motor.

Fuel pressure regulator on TBI / on fuel tank.

Fuel pressure 14.5psi/about 40psi.

Two injectors / six injectors.

Cruise control moved from servo to ECU.

EGR on intake / EGR between exhaust manifold and intake.

Exhaust crossover in intake / no exhaust crossover in intake.

Four V-belts / one serpentine belt.

No crank sensor / crank sensor hole in transmission bellhousing.

Can set static timing / can't set static ignition timing.

SMEC with the power board inside the housing / SBEC with it all on one board.

Resistance wiring values for cruise control switches.

Physical mounting of the steering column to the intermediate shaft.

Wiring for headlights.

Addition of PDC in 1991 under the hood to split the power lines up.

Wiring of the bulkhead fitting.

Grab both FSMs and cruise through them sometime.

You'll really need a 1995 donor for all the wiring.

And no, what the ECU does is "Let's activate OD. Did the engine speed slow down? No? Then OD's farked!" logic.

Not easy to trick that.

I mean, it's doable - VERY doable - with the proper donor.

But if you have a 5 speed 1995 donor, why futz with the ECU?

RwP

 

That won't work. On the RH trans, the PCM only controls O/D, and TCC. It expects to see an RPM drop when engaging either of them, and a resistor simply won't do that. Either need the correct ecm, an automatic trans, or live with the CEL being on.