PCM compatibility

[Irun]

Will this work?

Swapping a PCM out of a 2003 Rubicon into my 2003 non-Rubicon Sport. Both PCMs are for an automatic and non-SKIM.

Reason for doing so, I'm shipping off the Sport PCM to have the SKIM added and I'd like to be able to move the Jeep while I'm waiting. It's not critical, but since I have another computer, it doesn't hurt to ask!

 

[Apparition]

I'd ask @Wranglerfix

 

[Irun]

Completely forgot that one! Paging @Wranglerfix

 

[Wranglerfix]

I can program and delete skim from either of those ECM’s for you. The automatic part numbers should end in 386AD and 096AI.

 

[Irun]

I can program and delete skim from either of those ECM’s for you. The automatic part numbers should end in 386AD and 096AI.

At this point I've got the computer, lock cylinder, new SKIM, and new uncut keys boxed up to ship to Blaine. I was really just curious whether I can use the Rubicon computer to start and run the Jeep, while I'm waiting.

 

[CharlesHS]

At this point I've got the computer, lock cylinder, new SKIM, and new uncut keys boxed up to ship to Blaine. I was really just curious whether I can use the Rubicon computer to start and run the Jeep, while I'm waiting.

As long as you are sure the ECU is the for the same year, there is no SKIM enabled and for the same transmission; there wont be a problem. There are only certain years that are cross compatible.
When SKIM was installed in my '01 Sport; the ECU's SKIM was enabled, but the module and keys would not talk to the ECU (bad module and chips set) so the vehicle would not start after enabling SKIM. We temporarily installed a '02 ECU manual trans w/o SKIM until the new module and keys were sourced.

 

[mrblaine]

At this point I've got the computer, lock cylinder, new SKIM, and new uncut keys boxed up to ship to Blaine. I was really just curious whether I can use the Rubicon computer to start and run the Jeep, while I'm waiting.

Yes, it will start run and drive even with a PCM for the wrong trans. (in this case)

 

[mrblaine]

As long as you are sure the ECU is the for the same year, there is no SKIM enabled and for the same transmission; there wont be a problem. There are only certain years that are cross compatible.
When SKIM was installed in my '01 Sport; the ECU's SKIM was enabled, but the module and keys would not talk to the ECU (bad module and chips set) so the vehicle would not start after enabling SKIM. We temporarily installed a '02 ECU manual trans w/o SKIM until the new module and keys were sourced.

We put a 98 XJ PCM in a 01 TJ and drove it around. We routinely use non matching trans PCM's to move vehicles around. In the same years, what happens is you get the upshift light if you use the manual PCM in an auto.

The only ones we haven't tried are the 05-06 manual PCM in an auto and vice versa.

 

[CharlesHS]

We put a 98 XJ PCM in a 01 TJ and drove it around. We routinely use non matching trans PCM's to move vehicles around. In the same years, what happens is you get the upshift light if you use the manual PCM in an auto.

The only ones we haven't tried are the 05-06 manual PCM in an auto and vice versa.

Thank you for the additional ECU information...

 

[Irun]

I finally got around to installing the 2003 PCM. Although it allows me to start and move the Jeep, it can't be driven on the street. As soon as I hit 30 mph, based on the GPS, the Jeep starts missing, almost like you're hitting a rev limiter. What's interesting is that while the GPS reads 30 mph, the speedometer reads 95 mph.

 

[mrblaine]

I finally got around to installing the 2003 PCM. Although it allows me to start and move the Jeep, it can't be driven on the street. As soon as I hit 30 mph, based on the GPS, the Jeep starts missing, almost like you're hitting a rev limiter. What's interesting is that while the GPS reads 30 mph, the speedometer reads 95 mph.

You have something else going on. There are lots of instances where the Rubi speedo sender has been used to send the signal to the non Rubi PCM so something else is pushing the speedo signal x 3 which is bouncing you off the rev limiter. Try unplugging the sender at the t-case and taking it for a test drive.

 

[Irun]

You have something else going on. There are lots of instances where the Rubi speedo sender has been used to send the signal to the non Rubi PCM so something else is pushing the speedo signal x 3 which is bouncing you off the rev limiter. Try unplugging the sender at the t-case and taking it for a test drive.

You nailed it! I have a SpeedoHealer inline with the 241. It worked fine with the original computer, but not with the Rubicon computer. I unplugged it and ran it up to 45mph with no issues.

 

[Sleddin650]

Hey guys, hoping to bring this thread to life again. I have the exact same issue as irun where my speedometer goes to 95 and I can go past like 20 mph. I just replaced my non rubicon ecu with a rubicon ecu and this happened. I took the advice and disconnected the speed sensor at the trans and it runs great but I have no speedometer now. Lol. What am I missing here? Is there a rubicon speed sensor?

 

[mrblaine]

Hey guys, hoping to bring this thread to life again. I have the exact same issue as irun where my speedometer goes to 95 and I can go past like 20 mph. I just replaced my non rubicon ecu with a rubicon ecu and this happened. I took the advice and disconnected the speed sensor at the trans and it runs great but I have no speedometer now. Lol. What am I missing here? Is there a rubicon speed sensor?

The Rubi PCM is looking for a vastly different number of pulses per minute to drive the speedo. You will need to do a digital correction device on the 231 output to the PCM. There is not a large enough speedo gear to slow it down enough to read correctly so you have to do it digitally.

 

[unknowntj]

I can program and delete skim from either of those ECM’s for you. The automatic part numbers should end in 386AD and 096AI.

@Wranglerfix

I purchased a jeep that apparently was pieced together. The vin does not match the motor that it has. It ran great for some time but has recently failed. I am in the process of trying to source a new ECM.

It's a 2.5L 4 cylinder manual, it does not have a SKIM as it's a fully metal key.

What year ECM can I purchase?

If you need more details, feel free to ask. Thanks in advance

 

[AndyG]

At this point I've got the computer, lock cylinder, new SKIM, and new uncut keys boxed up to ship to Blaine. I was really just curious whether I can use the Rubicon computer to start and run the Jeep, while I'm waiting.

We need to all pause a few and be thankful for Mark at Wranglerfix.

He is a good egg and plays a vital role here.

I’ve seen his inventory- it is impressive.