Can you swap pcm's from one vehicle to another?

[nicpaige]

I may have a PCM issue and I am wondering if I can swap my pcm into another 2000 XJ automatic vehicle to see if the issue follows the PCM? I didnt know if the PCM's were VIN specific.

 

[wizardPC]

Does either vehicle have SKIM?

 

[gradon]

Is your 2000 cali or federal emissions? Try it in a similar spec 2000. If cali, it also might work in a 2001.

 

[nicpaige]

Federal emissions, and it does not have a chipped key. I did talk with a dealer service manager today and he said they have no way of testing a PCM not installed in the vehicle.

 

[Alaskan89XJ]

Wow, what an ordeal. Do you live near auto junk yards that might have an ECU/PCM, etc., that you could obtain? Anyway, have you checked the mechanical connection of wires/plug into your ECU?

Got'ta pay to play sometimes.., perhaps you could have the dealer you went to--to pick up your XJ, take it to their shop to do the test, (or someplace cheaper), and let them further diagnose the issue. Like you've done everything but paint the tires, right?

http://www.naxja.org/forum/archive/index.php/t-1077354.html

Refurbished versus rebuilt ECU/PCMs.., http://www.cnet.com/forums/discussions/jeep-pcm-ecm-replacement-lesson-learned-323625/

Do I recall correctly that ECU/PCMs are VIN specific?

Here is another possible issue. http://www.buzzle.com/articles/symptoms-of-a-bad-body-control-module.html Indicating; Engine: Failure of the engine to crank up.

Just 2 cents more.

 

[Alaskan89XJ]

Failed CPS? Genuine CPS? Metal debris fouled CPS? Incorrect positioning of CPS? Bad wires to CPS?

ECU/PCM wiring plug fluctuating voltages via badly corroded terminals either side of firewall?

Frankly, my last 2 cents.., but please let us know about the final fix, ok? Curious minds.., and all of that.

 

[thejeepgod]

Since it does not have a chipped key...

Yes you can switch them around all you want as long as it is from the same year and the part number is the same (the 2 letters at the end dont matter). They are NOT vin specific.

Some other similar part numbers in the same year (federal vs CA emissions, and manual vs auto) can work also, but has to be from the same year.

if you google you should be able to find a chart that lists the p/ns between the years and what the differences are between them if you need it.

 

[lazyxj]

Yes you can switch them around all you want as long as it is from the same year and the part number is the same (the 2 letters at the end dont matter). They are NOT vin specific."

In some states, California included, that require testing every one or two years, when replacing the computer and not just testing, the VIN and mileage must be correctly set so not to upset the state's database pertaining to car's VIN and mileage, compared to when it was last tested .
Federal law prohibits tampering with the odometer.
Resetting can be done by the dealer and many aftermarket rebuilders and tuners

 

[lazyxj]

Yes you can switch them around all you want as long as it is from the same year and the part number is the same (the 2 letters at the end dont matter). They are NOT vin specific."

In some states, California included, that require testing every one or two years, when replacing the computer and not just testing, the VIN and mileage must be correctly set so not to upset the state's database pertaining to car's VIN and mileage, compared to when it was last tested .
Federal law prohibits tampering with the odometer.
Resetting can be done by the dealer and many aftermarket rebuilders and tuners

 

[Green Mesa XJ]

I don't know about all the intricacies of a digital mileage. But it can be done as long as the keys are not chipped. Other people have done it with this year tying to trouble shoot problems.

Used interchanges basically shows 4.0 auto or manual, federal or "low emissions"
It apparently has to be the same year.
be a number like 56041634AF, the last 5 being what you try to match, 634AF.

http://board.moparts.org/ubbthreads/upload2/5798559-DodgeFlashAvail.pdf
this link has all the computer numbers, just search though it for the XJ numbers and later replacement #.

Looks like most of the 2000 4.0 fed auto xj were later replaced with 56041634AG.

EDIT: according to ebay sellers in the example give 643AC through AG will work, so you have some wriggle room in finding a substitute.

 

[nicpaige]

Thanks for the tips and info guys. I have a bunch of testing and probing to do.

 

[thejeepgod]

In some states, California included, that require testing every one or two years, when replacing the computer and not just testing, the VIN and mileage must be correctly set so not to upset the state's database pertaining to car's VIN and mileage, compared to when it was last tested .
Federal law prohibits tampering with the odometer.
Resetting can be done by the dealer and many aftermarket rebuilders and tuners

The mileage is stored in the gauge cluster itself. If you change out the PCM the mileage displayed will not change.

 

[thanasi85]

Should be fine I swapped out a 96 2x4 pcm about 5 years ago with a 96 4x4 one from the junkyard and have had no issues at all and it smogs fine.

 

[lazyxj]

The mileage is stored in the gauge cluster itself. If you change out the PCM the mileage displayed will not change.

When ordering a new computer, from the dealer or a rebuilt, either way, the vendor requires the VIN and mileage to program the computer to match the car, before shipping.
The odometer may store the mileage but to have the VIN match the car, a replacement computer needs to be changed in states that require emissions testing. Been there, done that.
This has nothing to do with running a used computer to see if the original is bad.

 

[dktool]

The mileage is stored in the gauge cluster itself. If you change out the PCM the mileage displayed will not change.

This
I replaced the pcm in my fed version '98 with a used one from eBay that had the exact part number. Mine had a dead fuel pump output signal.
I have had it smogged twice since without issue.