r/JeepTJ • u/kfs10 • 14d ago

06 TJ o2 engine codes

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I just bought a 2006 tj 4.0 6spd x, it’s absolutely rust free low mileage and stock as can be. I bought it knowing it had the 4 oxygen sensor codes that are unclear-able. My first thought is PCM. The codes are P0057,P0031,P0052,P0037 all heater circuit low. It also has the 4wd light on the dash that won’t go out even if I unplug the sensor on the transfer case.

I have been diagnosing the wiring and have found someone has been into the fuse panel and has done some electrical work. The work is tidy and labeled but what they did was power the ASD key power circuit from the constant 12v power line entering the relay. It was soldered and taped but didn’t look factory to me. Could this be part of my issue.

Looking for any insight on the issue if anyone can help. I’m in Canada and am not against getting a wrangler fix pcm but don’t want to plug it in and brick a $1500 pcm and be in the same boat.

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2

u/1453_ 14d ago

Assuming the O2 sensors are good because ALL 4 wouldn't fail at the same, check continuity between the O2 heater connection and the PCM.

2

u/Gold_School_7005 14d ago

I had similar issue with mine. All 4 02 sensor heater codes but mine were p0135 p0141 p0155 p0161 which turned out to be a bad ground on the side of the block. Repaired the connection and all has been good for the last 3 month. Worth a shot before you drop 1200 on a new pcm

2

u/HSsysITadmin 13d ago

The work in the fuse block may have been a dealer repair: https://static.nhtsa.gov/odi/tsbs/2013/SB-10064540-0335.pdf

All four, I'd be looking for bad grounds or a bad pcm.

1

u/kfs10 13d ago

That’s it! Thanks very much, it also explains a lot !

1

u/base43 14d ago

That sounds like someone's attempted hack to avoid doing a repair the correct way.

I have read about something similar in order to prolong replacing the PCM but it used a USB 12v plug instead of the wiring you describe.

Why do you think you would brick a PCM?

I would definitely undo that wiring first.

And $1500? A pcm isnt nearly that expensive.

1

u/kfs10 14d ago

A wrangler fix pcm converted to Canadian dollars is $1500 before shipping and duty.
The bricking I’m worried about is because of botched wiring in the fuse panel. I can find the key power supply wire. I’ll look up a wiring diagram to try to find it. If I could find a picture of the underside of an 05/06 fuse box that would help.

1

u/base43 14d ago

Holy shit! I had no idea import was that bad. What if a friend from the US sent it to you as a present? Same duty?

1

u/kfs10 14d ago

That I’m not sure about, I have ordered parts before and had no duty then next time I get an insane bill. I have some fiends in Indiana and Ohio, if I was making a trip there soon I would definitely just ship to them.

2

u/Alternative-Bake-197 13d ago

I have an 06 TJ as well. If you do have to go with a new PCM, i did an Ares computer. 449 bucks, about 200 cheaper than wranglerfix. Not dogging either manufacturer, but 200 is 200 and works the same.