dubbydoo

My 91 comanche was driving it today everything normal then its starts running rough and throws a check engine light . So I continue to drive it thing will not shift unless I get the motor up to about 4000+ rpms. I get it back to my shop neutral works and reverse works so im not sure the trans is bad any advise on what it could be?

Lowrange2

Does it have fluid in it?

4.0? Aw4? Turbo350?

dubbydoo

sorry yes new fluid aw4 4.0 4x4

dubbydoo

anyone got an ideas?

tjwalker

If you have a check engine light, the best strategy ALWAYS is to pull the codes.

Use the technology provided to you by your Jeep. Then you can plan your repair. Don't guess; anything less than getting the codes is pure guesswork.

Here's how to get those codes with your OBD1 diagnostic system. Super easy. Report back what you find.
------------------------------------------------------------------

OBD1 Models: 1991-1995
1) Start engine (if possible). Move transmission shift lever
through all positions, ending in Park. Turn A/C switch on and then off
(if equipped).
2) Turn engine off. Without starting engine again, turn
ignition on, off, on, off and on within 5 seconds. Record 2-digit
fault codes as displayed by flashing MIL.
3) For example, fault code 23 is displayed as flash, flash,
4-second pause, flash, flash, flash. After a slightly longer pause,
other codes stored are displayed in numerical order. When MIL begins
to flash fault codes, it cannot be stopped. Start over if count is
lost. Code 55 indicates end of fault code display.

salad

What kind of fluid in there? ATF+4 or Dexron/Mercon? ATF+4 has been known to cause slipping in AW4s. Is it still clean and not burnt?

Have you ever adjusted the TV cable? (aka kickdown cable, 2nd cable off of the throttle body) This helps control the transmission's shift points.

What code came up?

dubbydoo

ok thanks ill try to grab some codes tomorrow as far as fluid it was dex/merc and was clean when i checked it about a week ago thanks guys

dubbydoo

Strange pulled these codes got in and drove it trans seemed to shift fine about2k-2.5k Codes 12 15 24 27 i dont have a speed sensor hookeed up yet maybe exu going out?

tjwalker

As you have both shifting problems and a code (24) for the throttle position sensor which is very important in controlling shifting characteristics of the AW4, I would recommend replacing your throttle position sensor, clear the codes, then drive it and see if your shifting symptoms are resolved and if any codes return........

Don't buy a cheap TPS. Buy it from Napa or the Jeep dealer.

dubbydoo

Ok will do thanks for your help

dubbydoo

well wasnt able to go buy one today but i did unplug it and it didnt make a diffrence so maybe thats a good sign that it is bad crossing my fingers

NewJerseyXJ609

My 95 when i first bought it would buck and throw a check eng at 50mph. code 24. Changed the tps. Im having different issues now with it. But at the time that was the fix for exactly what your experiencing.

dubbydoo

Just replaced it and it seems like its back to normal thanks guys

NewJerseyXJ609

No problem