New XJ

So after being XJ-less for about 3 years I finally have jumped back in. 2001 2WD sport, pretty basic. Drove it home, had my first issues with an automatic transmission ever. A4W starts out fine, shifts ok. Stop at a traffic light for anything more than a pause and it won’t drive, just slips. Put it in park, turn engine off, wait for traffic light to cycle, restart, put it in drive and we’re off to the races. I have zero knowledge of automatics, solenoids or torque converters, did a quick search and couldn’t find similar symptoms.

I have an NP242 from my last XJ (97), if my trans is shot can I put a 97 A4W 4x4 compatible replacement in without having to mess with wiring & the TCM?

This XJ is nice, not hit, pretty clean, needs the usual front end & suspension tweaks to run full sized tires. Oh, and only 106,000 on it.

Mark

Having to shut off the ignition and restart the engine points to electrical and/or sensor issues more than to a mechanical issue. Unplug the Transmission Control Module and shift the gears manually with the floor shifter, same or different ?


Naturally you need to first make sure the AW-4 has the correct Dexron-III/Mercon fluid type installed, and that the fluid is clean and the fluid level is correct. Inspect the solenoid wire harness and the main transmission wire harness for damaged wires, chafed/melted wire insulation, corrosion, and pushed back wire plug pins. Test continuity of the wires. Use some contact cleaner on each plug and firmly reconnect them.

Consider buying a good used Transmission Control Module to swap in for troubleshooting. I do not recommend random parts swapping as a diagnostic process, but around here a used TCM is $8.

I would start by trying to pull any codes!

It doesn’t show any codes, no CEL. I tried to manually select gears as it was driving, didn’t seem to make much difference. I also noted that once restarted, it would begin to slip after awhile in normal driving, and had issues going up the few hills we have in north Florida. Im leaning towards wrong fluid or torque converter on the way out.

Diagnose first, then repair.

Unplug the Transmission Control Module and shift the gears manually with the floor shifter, same or different ?

while testing/inspecting wires, test the solenoids also.

Have you actually checked the fluid level?

I’ve not touched it since driving home Saturday. I work out of town and have been gone since Sunday afternoon. Plan of attack for the weekend is to check fluid, then disconnect TCM and try to drive it by shifting manually. Also hitting the junkyard to look at a donor for 4wd running gear. This issue may get resolved by swapping out the 2WD configured transmission for a 4wd one.

Agree with Tim, see if the issue goes away with bypassing the solenoids by disconnecting the TCU