05 PCM to 98 PCM

[nashjeep]

Not sure what all is different from 98 to 05. Probably the best thing to do before really getting into it is studying the pinouts of the 2005 and the 1998 harnesses from the FSM and comparing the 2.

Another thing to consider is the differences in the fuel systems. I think late model tjs run a higher fuel pressure than early models (not 100% positive on this) .

Most likely, just guessing, your 2005 tj body is going to end up with a complete wire harness from the 1998.


What is your goal? I personally would try to find another pcm for the 05. It is probably possible to swap complete harnesses, but that is going to be a huge project.

My situation was different. I modified my old harness to run a ccd tj cluster with a ccd style dodge ram pcm. If you plug in a scanner to my jeep, it comes back with a vin from a 2000 Ram pickup.

My goal is to save money
I own my tj for 6 years, I’ve changed 3 pcm’s and 4 42rle

Our weather is hot it reached 58c in summer
I tried everything to cool the pcm and gear but ended up changing them
So i said to my self why i will pay 1000$ for the pcm when i can buy a 98 pcm and harness for 150$
And manual transmission is way better and stronger than 42rle

So i buy the scrap 98 tj for just a 1200$ and its working great but the chassis is rusty that it cant be fixed but other things works just fine

Owning 05-06 tj here is like owning a bugatti no parts compared to 97-01 u can have them anywhere
Thats the reason for my swap


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[BeavisTJ]

My goal is to save money
I own my tj for 6 years, I’ve changed 3 pcm’s and 4 42rle

Our weather is hot it reached 58c in summer
I tried everything to cool the pcm and gear but ended up changing them
So i said to my self why i will pay 1000$ for the pcm when i can buy a 98 pcm and harness for 150$
And manual transmission is way better and stronger than 42rle

So i buy the scrap 98 tj for just a 1200$ and its working great but the chassis is rusty that it cant be fixed but other things works just fine

Owning 05-06 tj here is like owning a bugatti no parts compared to 97-01 u can have them anywhere
Thats the reason for my swap


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What sort of issues prompted you to get a new pcm?

I'm starting to think that's what issues I'm having.

 

[nashjeep]

What sort of issues prompted you to get a new pcm?

I'm starting to think that's what issues I'm having.

Start getting codes that you cant clear

Cars misfired randomly

Sometimes you need to switch off and back on to get everything works fine

Transmission most of the time on limp mode

Lose of power



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[Paul Ruggles]

My goal is to save money
I own my tj for 6 years, I’ve changed 3 pcm’s and 4 42rle

Our weather is hot it reached 58c in summer
I tried everything to cool the pcm and gear but ended up changing them
So i said to my self why i will pay 1000$ for the pcm when i can buy a 98 pcm and harness for 150$
And manual transmission is way better and stronger than 42rle

So i buy the scrap 98 tj for just a 1200$ and its working great but the chassis is rusty that it cant be fixed but other things works just fine

Owning 05-06 tj here is like owning a bugatti no parts compared to 97-01 u can have them anywhere
Thats the reason for my swap


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Sounds like swapping to the 1998 stuff is a solution then. Like I said before, your jeep probably is going to end up a 2005 body with a 1998 wire harness and drivetrain. If that's what you want to do, it's most likely possible.

You should really study the wiring diagrams for both jeeps before you start. Unless someone has done the exact same thing you are trying to do, we are all just guessing.

You asked about the ac . If the 1998 had ac, then it should be just a wire harness swap . If not, than the wiring diagrams may point you in the right direction to make it work.

I am only sure of what I have done myself. I do not have all the answers for what you are doing.

 

[derekmac]

Our weather is hot it reached 58c in summer

And here I think 30 is too damn hot! I couldn't imagine being in the temps you guys get!

 

[nashjeep]

And here I think 30 is too damn hot! I couldn't imagine being in the temps you guys get!

Yeah bro in the coldest winter the temperature reach 17c only
Now we are in spring and it 41 in the morning and 34 in the evening
But i used to it cause i was born here


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[mrblaine]

If it matters, I verified today that an 05 will start and run with the crank case position sensor unplugged.

 

[nashjeep]

If it matters, I verified today that an 05 will start and run with the crank case position sensor unplugged.

I knew that bro the PCM uses the cam position sensor to start the car in limp mode if the crank position sensor went bad or unplugged


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