aw4 shift problems

joe_peters said:

Not quite sure where this conversation is going, but here is a link to most everything you need to know about your AW4: http://www.transonline.com/transdigest/magazines/1997-10/Shift Pointers/index.html

Read, then post up with any specific questions you have.

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joe_peters said:

Ok, with an electronic auto trans the first thing to do AFTER checking fluid level and condition is to determine if the problem is electrical or hydraulic/mechanical in nature.

You didn't share much info, so the TCU--transmission control unit--is under the dash, either on the passenger's side for earlier XJs or driver's side for the later XJs. Silver box, simply unplug it and drive the vehicle shifting manually.

Shifting manually you should have 1st in 1-2; 3rd in 3; 4th in D; reverse, neutral, and park. If you have that, then your trouble is electrical.

Things to check electrical, in order of ease:

1. Adjust the throttle pressure cable: http://naxja.org/forum/showthread.php?t=1015963

2. Check the ground and reference voltage to the TPS, then check the output voltage of the TPS--needs to be 83 percent of the reference voltage. 87-90 are adjustable, 91 plus are not and must be replaced if out of spec.

3. There are two fuses, one is 7.5 amp and not the problem; the other is a 10 amp fuse that can be the problem. On the earlier XJs the 10 amp fuse is in a yellow wire close to the TCU; later XJs it in the PDC under the hood.

4. Test the solenoids--see the link I included in one of the earlier posts, you will need an ohm meter.

5. Test the wires between the solenoids and the TCU.

Post up what you find.

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pb_beaker said:

Well heres what happened:

1. I adjusted the throttle pressure cable and when I fisrt had it out it seemed like it was doing great. Untill the tranny got to running temp. Then it was even worse then before!

3. The 10 amp was fine.

2. When i tested it before adjusting it I got .90%. So I adjusted it and got it to .83%. Took it out for a test drive and SHAZAM it works great. No more hunting at cruzing speed. Easy and smooth shifts, WOW I could not believe how well it works now. The only thing now is that at cruzing spped it sometimes goes into OD. Im ok with that, less RPM's and less gas comsumption.

Thanks a million joe_peters. :cheers:

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