1987 Jeep Cherokee wagoneer Trans Problem PLEASE Help!!!

I have a 1987 Jeep Cherokee wagoneer Limited. Its has the aw4 auto trans. We where doing some repairs and had the jeep up on ramps for a week. After where got done fixing the timing cover. I went out to test and now it will not shift out of first gear. The only thing we mayhave done was my dad reversed the battery termanels, and the lights went on. The key was not on, and it was only for about 15 sec. So we replaced the trans module that didn't work, then we replaced the main computer that didn't fix it. We checked all the fuse ( even the in line fuse going to the trans module). We are thinking it a solenoid in the trans, but we didn't drop the pan yet. We also got a diagnostic and every thing came out good. Is there anything i'm over looking.. PLEASE Help!!!!

drop pan, check screen for metal. if you find any get a new tranny.

did you replace the tcu , sounds like you might have fried it , under the glove box

check the fuse for the TCU. If the TCU get's no power it doesn't shift outta first.

87manche said:

check the fuse for the TCU. If the TCU get's no power it doesn't shift outta first.

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If the AW4 TCU has no power, it should stay in 4th gear in (D), 3rd gear in (3), and 1st in (1-2). Pulling the fuse and manually shifting is the way to test that a problem is not mechanical.

Usually, a shifting problem is caused by a bad Throttle Position Sensor. A bad throttle position reading will cause it to stay in first if it thinks the pedal is to the floor, or it will upshift immediately if it thinks the pedal isn't being pressed.

Could still be a bad #2 solenoid, though as #1 is on for first, and both 1-2 are on for second. A bad output shaft speed sensor (drivers side under the xfer case linkage plate) would cause the TCU to think you're sitting still.