auto ecu

[89comanchesleeper]

i have the chance to buy a 93 4.0 with harness and all the goodies to do the 4.0 swap in my manche. only thing is its comin out a xj with a auto trans. my manche is a 5 speed and i wanna keep it that way i understand i will have to find a ax15. but will the ecu out of a auto work with a ax15 trans? :help:

[JeepcoMJ]

i have the chance to buy a 93 4.0 with harness and all the goodies to do the 4.0 swap in my manche. only thing is its comin out a xj with a auto trans. my manche is a 5 speed and i wanna keep it that way i understand i will have to find a ax15. but will the ecu out of a auto work with a ax15 trans? :help:

 

short answer; yes, it will work.

 

 

there is still an automatic trans computer up to 1996, '97 is the year that trans controls were part of the ECU.

 

it *should* work just fine.

 

BUT you will have to do some splicing to make your reverse lights and neutral safety switch work...the connectors in that area are not the same.

 

If converting from '87-'90, you will also need to use a '91-'93 (maybe '94) flywheel...yours will not work.

 

If that is the case, you need each and every single electrical part for the engine bay and dash. you WILL be removing your dash to do this swap. you will also need to do a "crossover" harness from xj to mj to make your rear harness work. IIRC, it is mfpdm did a write-up for this in DIY

[89comanchesleeper]

ok wow that seams like a lot of stuff to do with the harness. and I'm not good with that lol. but thanks man :cheers:

[kastein]

i have the chance to buy a 93 4.0 with harness and all the goodies to do the 4.0 swap in my manche. only thing is its comin out a xj with a auto trans. my manche is a 5 speed and i wanna keep it that way i understand i will have to find a ax15. but will the ecu out of a auto work with a ax15 trans? :help:

 

short answer; yes, it will work.

 

 

there is still an automatic trans computer up to 1996, '97 is the year that trans controls were part of the ECU.

 

it *should* work just fine.

 

BUT you will have to do some splicing to make your reverse lights and neutral safety switch work...the connectors in that area are not the same.

 

If converting from '87-'90, you will also need to use a '91-'93 (maybe '94) flywheel...yours will not work.

 

If that is the case, you need each and every single electrical part for the engine bay and dash. you WILL be removing your dash to do this swap. you will also need to do a "crossover" harness from xj to mj to make your rear harness work. IIRC, it is mfpdm did a write-up for this in DIY

Nope, on the 4.0L drivetrain the TCU and ECU have always been separate in MJs and XJs, the 97 and later TCUs are just smaller, smarter, and mounted in a different spot. On the 2.5L drivetrain with the chrysler transmission (iirc) the TCU functionality is part of the ECU.

 

Shouldn't affect the outcome of the OP's project though since he's got a 93 donor, and the vehicle it's going into had a manual so the TCU won't matter. I believe you should be able to use either a 4.0L/AX-15 ECU, or the 4.0L/AW-4 ECU with the TCU connected to the harness but not connected to the transmission since it's a 93 (manumatic friendly) but I am not sure.