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tps and reverse


NAXJA Forum User
does the tps sensor have anything to do with reverse? the reverse went out on my aw4 trans. so I thought. swapped in a different trans from a jeep salvage yard and now I still have the same problem no reverse. if I stomp hard on the throttle it will lurch a little but other than that it feels like neutral please help
don't know for sure...but i would try disconnecting the switch for the back up lights...then the computer doesn't know what gear you're in. If that solves the problem, then you know the two things are related.

Also...are you sure you have enough ATF in it?
JOHNX I put 5 quarts of fluid in and does show full. I also disconected the the tcu today and manually shifted through all the gears but still didnt get rverse to work. I just find it extremly unlucky that this trans has the same problem as the original i just replaced
That seems like too much of a coincidence. Maybe the shifter isn't putting the trans completely in reverse. Disconnect the cable at the trans, and see if it'll go (more fully) into reverse......
The first two things on the troubleshooting list (after pulling the TCU fuse) are shifter cable adjustment and TV cable adjustment. The rest are bad clutches or brakes.
I´d check things common to both tranny´s, like the shifter/cable, the TV cable, the torque conerter? and even as a last resort, blow through the tranny cooler line. I had one trans with pressure problems, that had a partially plugged trans cooler. Then if that didn´t do it, get a pressure gauge, a book and do a pressure test.
Possible both tranny´s have the same problem, but I´d make sure before swapping out another one.
this is a strange one for me. I will check the trans lines but would that just cause a problemwith the reverse? I also disconected the the shifter cable and mannually shiffted the lever by hand and the didnt help. also i should note that after starting up the jeep the first time after instalation of the new trans the reverse worked 2 times on the first 2 test but then never worked again. this is to weird.
Chances are if your getting park and neutral in the right places, your getting reverse also. Check your fluid level again, the last time I had the torque converter out and emptied it, I was adding oil forever. I kept looking under the XJ to make sure it wasn´t leaking out the bottom. I´d run it for awhile, then add, the run, then add, seemed like forever.
I was thinking (nothing really to base my thoughts on, but instinct) that low pressure may be enough to operate the forward gears, but not enough to get reverse to engauge. Low pressure can come from the pump, the TV cable adjustment, a plugged or paritally blocked cooler line, a partial valve body or solenoid blockage. Low pressure may cause first to slip a bit and the other gears to shift late. First and reverse and even I believe some other gears share some brakes and clutches with reverse. Doesn´t seem likely just reverse would go out or act up.
I sure don´t know the AW4 like I do some other trannies, I´ve rarley had to work on one.
Check the cable running from your TB to the tranny. If the cable is really loose it will cause low pressures. Most times when I´ve had reverse go out of a tranny there was a pile of bits and pieces in the pan.
Junk in the valve body is always a possibility. When all else has failed I have a make or break, last resort trick, that may dislodge junk from the valve body, but then again may break your tranny for good.
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