05-06 PCM issue is solved

[Apparition]

Jesus...that is like a grand. How did you know you needed this, any tells other than CELs?

I was on my way back from Moab, in the middle of Nebraska, on a Sunday afternoon when the jeep went into limp mode for a random misfire, can't recall the code.

Checked all the plugs at the next exit.

Ran fine on a restart.

Headed back out on I80, hit about 55 and back into limp mode.

After some F'n around and test runs I determined I couldn't exceed 55 or the load would cause a misfire.

Set the cruise and drove the rest of the way home under 55 mph.

Next day I hooked up a blue driver OBD2 dongle and it said I needed a new cat.

I ordered that setup and had it in a couple days.

Once I pulled the exhaust it was clear looking in it the internals of the cat were loose and blocking the exhaust flow.

New cat setup fixed it all.

If you think it's cats the best way to tell is to pull them and take a look. Especially if they now cost over $800. Probably be cheaper to have someone weld in new ones.

 

[skrelnik]

I was on my way back from Moab, in the middle of Nebraska, on a Sunday afternoon when the jeep went into limp mode for a random misfire, can't recall the code.

Checked all the plugs at the next exit.

Ran fine on a restart.

Headed back out on I80, hit about 55 and back into limp mode.

After some F'n around and test runs I determined I couldn't exceed 55 or the load would cause a misfire.

Set the cruise and drove the rest of the way home under 55 mph.

Next day I hooked up a blue driver OBD2 dongle and it said I needed a new cat.

I ordered that setup and had it in a couple days.

Once I pulled the exhaust it was clear looking in it the internals of the cat were loose and blocking the exhaust flow.

New cat setup fixed it all.

If you think it's cats the best way to tell is to pull them and take a look. Especially if they now cost over $800. Probably be cheaper to have someone weld in new ones.

Yeah, I may need to pull the cats off and take a look inside. Sucks, but that is clearly the only way to know. AfE has a set for around $600 so I may go that route, but need to do more research.

Thanks

 

[rasband]

When I bought it, it was only $250!!!!!!!!! Worked great

Holy cow, I bought one last summer that is now on a buddy's rig for the same ($250). Guess he owes me more money since we just installed it a few weeks ago!

 

[skrelnik]

Holy cow, I bought one last summer that is now on a buddy's rig for the same ($250). Guess he owes me more money since we just installed it a few weeks ago!

This pandemic is crazy, prices going up like that. I may need to sell the PCM just to buy the cats...

 

[Wranglerfix]

@skrelnik

The 0431 leads back to:

• Exhaust system leaks
• Loose front or rear HO2Ss
• Faulty front heater O2 sensor
• O2 sensors harness is open or shorted
• O2 sensors poor electrical connection
• 
  Have you checked your exhaust for leaks?

 

[skrelnik]

@skrelnik

The 0431 leads back to:

• Exhaust system leaks
• Loose front or rear HO2Ss
• Faulty front heater O2 sensor
• O2 sensors harness is open or shorted
• O2 sensors poor electrical connection
• 
  Have you checked your exhaust for leaks?

My issue has been around for about 6-7 years and a few months back my oil pan was seeping oil so my Indy did that job, which involves removing the cats.

We did not look down the cats to see if anything was not right - 20/20 hindsight.

A few years back the O2 sensors were swapped for the correct ones etc etc.

The CEL went from all four O2 sensors (032, 038, 052, 058) to now 0431. Is there any more of a "tell" there?

I'm going to take the cats off next and see if anything looks fishy. If you have other thoughts please share. Thanks

 

[Yahtahhey]

My key warning light comes on and stays on. Any way to fix this issue?

 

[Yahtahhey]

First PCM gave me a Key warning light problem. @Wranglerfix sent a replacement and problem solved! Thank you for fixing the hard shift and working to solve the Key warning light issue!

 

[Wranglerfix]

I have come a long way over the past two+ years since this thread was started and I had a tee shirt on my site!

Thank you very much as I could not have done this without you!

 

[Inherited-LJ]

Update: did more investigating, and confirmed my LJ does NOT have the TCM as a part of the PCM. It is a separate unit.
That obviously does not solve anything… but if I do have to replace the whole unit, at least it’s not the whole PCM. At this point, I’ll take the small victory.

For anyone following along… after much troubleshooting it was determined that the TCM was the culprit. I ordered a new one and installed just now. Codes are gone and no more limp mode… at least for now. Seems to have fixed the problem, although as I mentioned in the quoted post, it’s not the same PCM issue that 05-06 TJs have. It was (at least I hope) a bad TCM but it’s a stand-alone unit on my 04.

 

[recon_rider27870]

I know this is my first post but I have to give wranglerfix my word. Called him Friday and talked to him and he was 100% positive it was my pcm so he sent one out Friday. Got it in today and put it in and sure enough so far so good shifting great and no codes either. Time will tell if jt holds up but for now it's great and a great guy to deal with.

 

[astjp2]

I know this is my first post but I have to give wranglerfix my word. Called him Friday and talked to him and he was 100% positive it was my pcm so he sent one out Friday. Got it in today and put it in and sure enough so far so good shifting great and no codes either. Time will tell if jt holds up but for now it's great and a great guy to deal with.

Welcome to the tribe!

 

[recon_rider27870]

Welcome to the tribe!

Thank you sirSeems like a bunch of good jeepers here.

 

[MountaineerTom]

I know this is my first post but I have to give wranglerfix my word. Called him Friday and talked to him and he was 100% positive it was my pcm so he sent one out Friday. Got it in today and put it in and sure enough so far so good shifting great and no codes either. Time will tell if jt holds up but for now it's great and a great guy to deal with.

I'm a little over 2-1/2 years on one of Mark's PCM's with no issues since installing it.

 

[Wranglerfix]

Thank you very much @recon_rider27870 and the rest of you as well. I greatly appreciate all of the support.

 

[recon_rider27870]

Thank you very much @recon_rider27870 and the rest of you as well. I greatly appreciate all of the support.

its hard to find good honest people now days but when I do find someone like that i put my full support behind them.

 

[Yellojeep]

Just gave him a call today and ordered one for my "rare" 2006 LJ Rubicon 6 speed that I have been chasing a limp mode / P0340 code on.

 

[WranglerFire]

I have not had very good luck with Wranglerfix. Mark has sent 4 different units but each one spits out codes, different ones on each too. I have to pass emissions by month end, any suggestions? 2005 Wrangler Rocky Mountain Edition, runs great, 90k miles, new tires, new soft top windows, new battery. Would consider selling if Mark can't get me a PCM that works - I am in Chicago area.

 

[Wranglerfix]

I have not had very good luck with Wranglerfix. Mark has sent 4 different units but each one spits out codes, different ones on each too. I have to pass emissions by month end, any suggestions? 2005 Wrangler Rocky Mountain Edition, runs great, 90k miles, new tires, new soft top windows, new battery. Would consider selling if Mark can't get me a PCM that works - I am in Chicago area.

What is your name? Order number?

 

[rasband]

I have not had very good luck with Wranglerfix. Mark has sent 4 different units but each one spits out codes, different ones on each too. I have to pass emissions by month end, any suggestions? 2005 Wrangler Rocky Mountain Edition, runs great, 90k miles, new tires, new soft top windows, new battery. Would consider selling if Mark can't get me a PCM that works - I am in Chicago area.

Did Mark say they are the PCM's fault? Seems like maybe there's some things to address - especially if those same PCMs don't have the same issues in other rigs.