RHD 06 keeps triggering limp mode

[TrowaB]

Hi all new jeep owner in the house. I recently bought my first jeep for delivering mail and things were great at first. I understood it was pretty rough and was a fixer upper but I also needed it with my other car stuck in the shop and the jeep was running decent for a few weeks. When I bought it the check engine light was on which showed ambient air temp sensor so I ordered and replaced it but that didn’t fix my cel. I was just getting to enjoying it and BAM limp mode, my only signs had been a slightly rough shift out of 1st. I take it to the transmission shop in town and they say yep bad solenoid pack and change it. I am back to enjoying my new ride for about a week then BAM limp mode. At this point I’m really struggling cause I have so much money tied up into these two vehicles that are stuck in the shop and neither can earn me any money. I do some research on here and decide I may need a new PCM so I purchase the wrangler fix pcm and install it. This plan felt smart as i was with my wife out of town having a baby so it was about all I could do from out of town to get it hopefully moving. When I get home and install the pcm the jeep was still stuck in limp so I took it back to the shop that fixed it the first time. They warranty the solenoid and send it back. The next time I’m driving it kicks to limp again which I was able to remedy by turning of and on a couple times. I keep getting the same ambient air temp code and have had some potential cam/crank failures as well. I changed the crank sensor and while doing so noticed some other shoddy things going on. Just above the crank sensor was another sensor I am unsure what it is, but it’s wires are toast so I am hoping someone know what sensor I’m talking about so I can source a plug for it. My best guess is oil pressure but the gauge is fine. I finally have a couple days off this week and am hoping to get after chasing down this problem. I suppose I am hoping someone can give me some useful links of any other things I need to be checking.

 

[Duck Doctor]

I owned a 2006 RHD TJ and sympathize with your issues. Please post some pics of the melted sensor wire location and also post all the fault codes.

What brand crank sensor did you install?

 

[TrowaB]

The pictures I’ll have to get tomorrow, but I do have codes from today. I don’t have a scan tool so the auto parts store ran them.

“Primary code”
P0073

“Secondary codes”
P0016
P0700
P1775
P0846
P1684
P0218

 

[JKP]

Was the temp sensor in the air intake the one you changed? If so, check the wiring to it.

The 05 and 06 have an issue with the OPDA which contains the cam sensor on the right side of the engine. You will probably have to change out the OPDA and while you're at it, inspect the cam gear for wear. Keep the OEM cam sensor though in case the one in the new OPDA is problematic.

Have you disconnected the battery to reset the trans codes? The new PCM should have helped with those.

The oil pressure switch is on the right side of the engine blk near the oil filter.

You may want to invest in a OBDII bluetooth code reader which can be used with a smart phone. It will let you read and reset codes. They are not that expensive.

 

[TrowaB]

Ambient air sensor I changed was in front of radiator.

I have reset the transmission codes and had readings where it’s fine but it kicked limp today so I had it read before disconnecting battery.

I’m gonna guess that the oil pressure switch is the sensor in question, I’ll get picks of tomorrow, it’s wiring to the plug is essentially non existent, but seems odd the gauge shows perfect reading so will get pics first.

 

[JKP]

It's just a switch, if you have 6 PSI of oil pressure, the PCM is happy and will move the gauge to the middle of the gauge.

Possibly a wiring issue with the temp sensor.

P0016 will put it in limp mode, not sure about the trans codes as I have a MT.

 

[TrowaB]

I know I’m just a shade tree kinda guy at best, so hear me out. If the transmission was overheating would that kick a code? I’m really struggling right at the moment out on a mail route in the middle of nowhere. It will “fix” itself with a shut off and restart but then when I try to get up to speed it does erratic shifting followed by stuck in 2nd. It is hot as can be today.

 

[TrowaB]

I know I’m just a shade tree kinda guy at best, so hear me out. If the transmission was overheating would that kick a code? I’m really struggling right at the moment out on a mail route in the middle of nowhere. It will “fix” itself with a shut off and restart but then when I try to get up to speed it does erratic shifting followed by stuck in 2nd. It is hot as can be today.

Also meant to mention slight smell of antifreeze from the ac and when it starts acting wonky the air gets warm.

 

[TrowaB]

This is the wasted sensor plug I was talking about.

This is the same sensor so you can see where it is in relation to the oil filter.

When I stopped today at an old farmers house to hose down the tranny to try and cool it off some I noticed some tapped in wiring going to this sensor that sits on top of the rear end of the tranny.

 

[TrowaB]

When I did stop and hose off the tranny she ran good again for about 5 miles but started acting up again before I finished my route.

 

[JKP]

Wow, that harness has been hacked on. You can pull up the wiring diagrams in the FSM under Resources.

 

[TrowaB]

Still no luck, this thing is really beating me up. Please I’m begging for some help on this thing. I have done soooo much since I last posted so I’m gonna start from the top in order of what all has been done.

All of this started with a no shift stuck in second symptom. There have been many codes along the way but the ones that it keeps popping now are

Persistent codes
P0016
P0073

Once shifting issues start then I get
P0700
P0846

Transmission solenoid pack was changed by a local shop, they put new filter and “universal trans fluid” (this is what the receipt says)

No shift happened again, I purchase wranglerfix PCM install it and still have issues.

Then I took it back to the shop, they said they “warranted the solenoid pack”

Happens again and I start poking around. I spent hours cleaning all the crud off the engine and tranny then put fresh oil and coolant along with new thermostat and housing.

Still not working properly, i change the OPDA. Old one did appear to be on its last leg (I bought the crown Opda from recommendation on here)

Still not working then radiator cracks on top so I install new radiator.

Still not working so I decide it’s time to go to the dealer. I had found that in the FSM it said a relearn was required if the solenoid pack or pcm were changed. I had high hopes for this. The dealer checked the voltage going to the speed sensors and the transmission itself and said they were fine. They performed the relearn and today I get test it out and still not working.

After work tonight I changed the input speed sensor and ordered the output sensor. I also put a new pigtail on the output sensor. (I had read here that if those are faulty your cruise control won’t work. My cruise can light up as if to turn on in park but when I start moving it shuts off)

Please if anyone has any input I’m listening. I need this jeep and I just can’t get it figured out. My latest theories/things I’ll consider next are… finish the trans speed sensor and pigtail fix. Try my best to find a factory cam position sensor. Change the tranny oil.

Does any of this sound like it is worthwhile?

 

[JKP]

What did the gear on the OPDA look like, what did the cam gear look like?

I have no knowledge on the AT, but I think you are only supposed to use ATF+4.

 

[TrowaB]

I looked down at the cam gear and it looked really good to me. I’m no expert but it seemed fine. I also as far as I can tell am not ever having any issues with the engine performance just the tranny.

The reason I mentioned the wording on the receipt and that I might try new tranny fluid is because of the people saying they are very particular about the ATF+4. I also think there is the potential even if the shop used the proper fluid that the fluid overheated when the radiator was failing.

I did finish up the new pigtails and sensors on transmission speed sensors today but still don’t have proper cruise control and didn’t drive it enough to see if tranny Would fail.

 

[rlinares40]

Sounds like an electrical problem to me. When I had the 4.0L in my 06 RHD I did the same as you where I just started replacing all the sensors when the actual problem were the wires themselves.

The FSM has a step by step for each trouble code where the 1st couple of steps is checking continuity and ohms for each of the sensor wires. It's a PITA but that's where I'd start.

The one time I went into limp mode it was due to having too little transmission fluid just FYI.

 

[TrowaB]

Yea, my next thoughts have been to fight the wiring. I have done some work on the wiring but need to dig deeper I think. I did finally get my other vehicle back so been taking a break from the jeep for about a week now, but need to get back at it.

I have been struggling to find a connector for the transmission solenoid, if anyone knows where I could source one without having to buy a whole harness that would be great help.

 

[LONGJP2]

Check where the harness goes behind the engine on the right side (your driver side).
That's a known problem area for bad wires.

 

[TrowaB]

Still struggling with this, have done some more diagnosing but have had no luck. Does anyone think a remanned valve body would be a smart plan?

 

[rlinares40]

Did you go through and check the wiring according to the FSM? It tells you what to replace depending on where it fails during the testing.

 

[TrowaB]

I wish I was smart enough to know how to check the wiring but I don’t know what I’m doing there. I own a multimeter but have the slightest idea how to use it.

I guess what I’m saying is I’m super intimidated by wiring. I did get fresh plugs for both of the 10 pin connectors on the transmission, but didn’t test the wires themselves cause I am not able to get a good grasp on wiring diagrams. If it was as easy as the top left pin in the solenoid plug goest to x position I could probably handle it.