Ecu/Ecm

[Master7122]

I went to the junkyard today to grab a ecu/ecm for my 87 Comanche, and in the yard was a 87 Comanche but when I pulled the ecu/ecm out someone had wrote on it "90 xj 4.0 cruise auto" will this still work in my 87? There's twp numbers on it one is S101140203 B and the other is 56006078

[DTA]

If you're pairing it with an AW4 it should be fine. I'm not 100% sure on mixing manual with auto, but this should help you out

http://comancheclub.com/topic/42705-more-power-form-renix-87-and-88/

[DirtyComanche]

The later ECM is better.

 

You can use an auto ECM in an manual.

 

Cruiser will tell you what the ECM is by P/N alone...

[Master7122]

The ecm came out of an auto Comanche and is going into an auto Comanche

[DirtyComanche]

It will work fine.

[Minuit]

You might actually notice an improvement in power over the old one. Fairly common to swap in a late Renix ECU to an 87 or 88, and that's probably why it's in that 87 to begin with.

[Ωhm]

I believe the manual ECU has a more aggressive spark advance curve, then the auto. Since you can wind up a manual trans.

[cruiser54]

I don't believe that is a late ECU. It will work though.

 

How come you're replacing it? 

[Master7122]

I don't believe that is a late ECU. It will work though.

 

How come you're replacing it?

My ecm got water damage, if its not a late model one then why would someone write that on there?

[DirtyComanche]

 

I don't believe that is a late ECU. It will work though.

 

How come you're replacing it?

My ecm got water damage, if its not a late model one then why would someone write that on there?

 

It might have been in two or three different vehicles by now.  Who knows.

[cruiser54]

I can't find a definitive answer via Google. I'd have to go look at my early ECUs that I swapped for newer.

 

89 to 90 usually end in 428 or 429.

[Eagle]

There's twp numbers on it one is S101140203 B and the other is 56006078

 

Something doesn't add up. ALL the ECUs in the factory parts manual for '87-'90 start with 5300, not 5600. None of them end with 6078.

 

for an '87, the manual tranny ECU should be 5300 5407 and for an automatic it should be 5300 5406

[Master7122]

I knew something didn't seem right. I tried looking it up and all I got was either its a ecu or the braking module for abs?

[HOrnbrod]

Renix ECU 56006078 is an alternate (superseded) part number for ECU 53005406. It's fine for your 87 and according to Renix-man Cruiser it's an upgrade.

 

https://www.moparpartsoverstock.com/p/__/MICROPROCESSOR--6-Cyl-Engine--Auto-Trans--1987-88--6-Cyl-Engine--wAuto-Trans--1989-90/6955890/JR007842.html

 

http://www.factorychryslerparts.com/products/JEEP/1989/CHEROKEE/MICROPROCESSOR--6-Cyl-Engine--Auto-Trans--1987-88--6-Cyl-Engine--wAuto-Trans--1989-90/4512217/JR007842.html