06 TJ will not run in reverse

Cajun001

Cajun001

Member
Joined
Mar 3, 2020
Messages
43
Location
Baton Rouge, La
Apparently this has been an underlying problem with what I had going on from earlier.
I have had some issues with Crankshaft Position sensor and Camshaft position sensor several times. I have replaced both using mopar sensor on Crankshaft position sensor. once I have that issue lined out I would have an intermittent issue with going in reverse. some times as soon as I put it in reverse the engine idle would drop and stall the engine as if the jeep did not know what to do when it was in reverse. sometimes it would go into reverse and back up but might stutter once but go in reverse but not with much power. Is there a program, sensor, switch that tells the computer all is well we are just backing up??? if I can find someone with the DBR3 scanner tool and re learn the sensors would that fix the reverse issue i am having? should i be looking for a damaged wire for some sensor and that's why it is intermittent?
 
The crankshaft/flywheel turns the same direction in forward/reverse so I doubt it's the CPS.

Since the transmission might just be slipping, try this... check the ATF level exactly (!) as described here.

Park on level ground then start the engine and leave it running. Shift through all the gears and then back to Park and leave it there. With the engine running, check the ATF level using the transmission's dipstick coming out from under the passenger-side firewall.

Make sure the ATF level is ALL THE WAY up to the full line. If it's not, bring it up to full by adding ATF+4. Make sure you ONLY add ATF+4. If the bottle doesn't say "ATF+4" in big letters on the front it's the wrong type of ATF.
 
  • Like
Reactions: Blondie70 and Zorba
I have recently changed the Transmission fluid and filter about a month ago, one of the reasons I changed it was because at that time I was having this issue with reverse. the Fluid I have in it now it is ATF LV which is what the manual called for. the level is all the way up to the full line. the engine will just drop out of idle and try to stall the engine but if I put it in Neutral it goes right back to idle.
But out of curiosity how would a low level in transmission cause the engine to stop idling and want to kill just by shifting into reverse?
 
  • Like
Reactions: Zorba
Cajun001 said:
I have recently changed the Transmission fluid and filter about a month ago, one of the reasons I changed it was because at that time I was having this issue with reverse. the Fluid I have in it now it is ATF LV which is what the manual called for. the level is all the way up to the full line. the engine will just drop out of idle and try to stall the engine but if I put it in Neutral it goes right back to idle.
But out of curiosity how would a low level in transmission cause the engine to stop idling and want to kill just by shifting into reverse?
Click to expand...
I'm sure your ATF "LV" was a typo and supposed to be IV which is aka '4'. Being low on ATF can cause all kinds of crazy problems if it has been too low too long.
 
thank, I did change the fluid and filter, the level was good before I changed and now it is still at top of full mark on stick when jeep is at normal temp while running. that is why i was wondering if there is some type of signal that is sent to the computer to indicate reverse and if the signal is not reading can it cause the engine to drop out of idle and stall unless i shift it back into Neutral, it appears and feels like it drives fine going forwards. the issue may have been there before but is getting worse. when I first got the jeep it backed up fine, but then I never put it under a load ie backing up hill or over a curb.. so it seemed ok, but has become worse as time progressed. just looking to see if anyone else had a similar problem
 
well that is about where I am at, at this point. I will have to start tracing wires to see If I can find something damaged. since I don't know much about Jeeps I have to start learning. this is frustrating!!
 
Cajun001 said:
well that is about where I am at, at this point. I will have to start tracing wires to see If I can find something damaged. since I don't know much about Jeeps I have to start learning. this is frustrating!!
Click to expand...
Start with the loom where it goes behind the valve cover on the right side. Get in there with a good light source and inspect it well to check for a chafed section. The loom in the later 04ish-06 is crap and disintegrates to nothing.
 
  • Like
Reactions: Ryan, SkylinesSuck, Apparition and 1 other person
mrblaine said:
Start with the loom where it goes behind the valve cover on the right side. Get in there with a good light source and inspect it well to check for a chafed section. The loom in the later 04ish-06 is crap and disintegrates to nothing.
Click to expand...
Do you have a recommendation for a good replacement loom Blaine? Now you have my thinking I should stay ahead of potential problems by replacing the loom on my 06 before it’s a problem
 
Vinman said:
Do you have a recommendation for a good replacement loom Blaine? Now you have my thinking I should stay ahead of potential problems by replacing the loom on my 06 before it’s a problem
Click to expand...
We have reloomed several. I use the high temp stuff with the blue or gray stripe on it. Takes about 5 different sizes and good harness tape. Someone posted up a vendor awhile ago that had small sections for sale. I use the stuff from Del City because we use so much of it. You on the other hand may not need 500' of 3/8" loom.
 
  • Like
Reactions: Vinman
I was chasing cps and ignition coil issues. Lots of people suggested the PCM. Turns out it was the wiring harness just like was suggested above. I would let it sit running in idle, reach in there, and start moving the harness around, especially in the area mrblaine described.
 
mrblaine said:
We have reloomed several. I use the high temp stuff with the blue or gray stripe on it. Takes about 5 different sizes and good harness tape. Someone posted up a vendor awhile ago that had small sections for sale. I use the stuff from Del City because we use so much of it. You on the other hand may not need 500' of 3/8" loom.
Click to expand...
Cool, a quick search found this supplier, not terrible pricing at approximately .30/100ft

https://www.cabletiesandmore.ca/nyl...MI89WymtT96gIVARLnCh1OCAFuEAAYASAAEgJGK_D_BwE
 
  • Like
Reactions: freedom_in_4low and Jerry Bransford
it just so happen I purchase some loom but it was some generic stuff, mainly because some of it was degraded and breaking apart. I did not research enough to know there is High temp. loom. the very harness you were talking about is one that has almost no loom left on it.
 
mrblaine said:
We use the Polyken harness tape. Don't use electrical tape, even the good stuff from 3M. It unwraps in the heat, especially if you are the stretch and tear it type. Use the Polyken and cut it with scissors or razor.

https://www.amazon.com/gp/product/B06XV9NQ11/?tag=wranglerorg-20
Click to expand...
Thanks, I learned years ago to not stretch the last few wraps of electrical tape, always lay it naturally and cut. Never thought about 3M not being good enough though, thats typically all I used. Will definitely get a few rolls of the Polyken to have on hand
 
Vinman said:
Thanks, I learned years ago to not stretch the last few wraps of electrical tape, always lay it naturally and cut. Never thought about 3M not being good enough though, thats typically all I used. Will definitely get a few rolls of the Polyken to have on hand
Click to expand...
We use about 5 different tapes depending.
 
Just getting back to finding time to work on jeep, I have replaced the loom on several wiring harnesses around the engine block and decided to really look at the sensors on the transmission to see if they were contaminated with oily dirt build up. the sensors on the transmission looked good, loom was in good shape and no build up of oily dirt, but when I got to the speed sensor at the outlet of the transfer case (at drive shaft) it was packed with oily dirt and took some time to clean it up well enough to be able to pull the connector apart. on the sensor itself, on the inside where the pins are located was half filled with a greenish oily substance, so I pulled the sensor and cleaned it out and also cleaned the wire connector side which had some wire insulation deteriorating. after cleaning it all up I put it back together and went for a ride, well now the sensor was not working because I was not getting a speed indication. ordered new sensor and installed. the issue with the jeep having issues while driving forward seem to have gone away, but I still have the issue with reverse. Not at first but after more than 5o miles driving I have intermittent reverse issues. no power in reverse!!! if I give it gas it will stutter and kill, will start right back up and will go in reverse with slowly applying gas as it backs up but if I give it too much gas it will stutter and try to kill. looking for suggestions!!! The transmission is not slipping while in reverse.
 
not replacing wiring harness, but replacing the loom on wiring harnesses around the engine block. it was suggested earlier in the post about replacing deteriorated loom to protected from the engine heat.
 
Top Bottom
Back