PCM Compatability Question ?

My Rig 97 4.0 AW4
I found a 97 at the Pick & Pull yard.
Still has the PCM in it, will it work in my Rig ?
Both have two code stickers, one covering the other, I'm thinking both have been rebuilt.

Mine: Top Sticker
280AD
P56041
TO777
JBSAB
Bottom Sticker:
280AD
P56041
TO817
JBSAB

Pick and Pulls:
Top sticker:
280AC
P56041
TO247
JBSAB
Bottom sticker:
280AC
P56041
TO217
JBSAB

If the PnP PCM is for an auto then you should be golden.

Hylander said:

My Rig 97 4.0 AW4
I found a 97 at the Pick & Pull yard.
Still has the PCM in it, will it work in my Rig ?
Both have two code stickers, one covering the other, I'm thinking both have been rebuilt.

Mine: Top Sticker
280AD
P56041
TO777
JBSAB
Bottom Sticker:
280AD
P56041
TO817
JBSAB

Pick and Pulls:
Top sticker:
280AC
P56041
TO247
JBSAB
Bottom sticker:
280AC
P56041
TO217
JBSAB

Click to expand...

The "P56041" and "280AC" or "280AD" lines are the relevant ones. Those indicate that the ECUs are part numbers P56041280AD/AC. Yours is rev AD, the P-n-P ones are rev AC, this means there may be slight hardware changes and firmware updates but it should run as it is the same major part number. Make sure they're for the same transmission setup as yours, and you will want to have the mileage and VIN updated - also make sure they do not have the security system that disables the vehicle if disconnected because this will result in them being useless unless you power the junker up with everything connected, disable the security system, then disconnect the ECU.

kastein said:

The "P56041" and "280AC" or "280AD" lines are the relevant ones. Those indicate that the ECUs are part numbers P56041280AD/AC. Yours is rev AD, the P-n-P ones are rev AC, this means there may be slight hardware changes and firmware updates but it should run as it is the same major part number. Make sure they're for the same transmission setup as yours, and you will want to have the mileage and VIN updated - also make sure they do not have the security system that disables the vehicle if disconnected because this will result in them being useless unless you power the junker up with everything connected, disable the security system, then disconnect the ECU.

Click to expand...

How do I tell if it has a Security System ?

the codes/part numbers don't matter. As long as it is from a 97-99 with an auto you will be fine. I researched this a lot when I had to replace my pcm. The dealers tried telling me the part numbers had to match and it needed to be reflashed also ($150). I listened to another member on here and got a used pcm. Has worked fine ever since, no reflashing, just plug it in.

kastein said:

Make sure they're for the same transmission setup as yours, and you will want to have the mileage and VIN updated - also make sure they do not have the security system that disables the vehicle if disconnected because this will result in them being useless unless you power the junker up with everything connected, disable the security system, then disconnect the ECU.

Click to expand...

Just curious, if he's got an auto shouldn't the PCM from a manual work? I would think it would just be ignorant of the presence of the TCU on the obdii bus.

Both mine and the Donor are AW4 auto's

lawsoncl said:

Just curious, if he's got an auto shouldn't the PCM from a manual work? I would think it would just be ignorant of the presence of the TCU on the obdii bus.

Click to expand...

I think it should, but I'm not sure if that'll set off some sort of flag during a vehicle inspection - I'm pretty sure the wrong VIN and mileage will though. Apparently the donor and his XJ are both aw4 equipped though, so I guess it's not an issue at all...

I believe it SHOULD be possible to reflash any ECU for a given model year back and forth between auto and manual, as I can't imagine the engineers who designed it actually making the hardware different, just the firmware, but you never know... PS, your ECU part number there comes up in my parts catalog as being for a 97 4WD Automatic 4.0L XJ with LHD or RHD and California emissions. Both it and the donor (56041280AC) come up in the MOPAR parts ordering system as being superseded by part number 5010403AA, which has an MSRP of $600 :scared::shocked::scared::shocked: I would take my chances with the junkyard one.

jeepster_259 said:

The dealers tried telling me the part numbers had to match and it needed to be reflashed also ($150). I listened to another member on here and got a used pcm. Has worked fine ever since, no reflashing, just plug it in.

Click to expand...

My '96 had a recall to flash the PCM. Is this what they were referring to? I thought it was just '96s.