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13 hours ago, Eagle said:

Shifting is controlled by solenoids. If it shifts manually, the transmission isn't the problem. I don't know how to check out the solenoids, but that's where I would look next.

 

:doh:  Completely forgot about the solenoids. Here's how to check the solenoid coils w/o pulling the tranny pan. It's done at the white 7-pin connector on the AW4 harness in the transmission tunnel. On the below diagram, pin B is tied to the ground side of each solenoid. Use an ohmmeter to check for a solenoid coil resistance of 12-15 ohms across pins G to B (S1), F to B (S2), and E to B (S3). An open circuit (infinite resistance) indicates an open solenoid that must be replaced. 

 

solenoids.jpg.e323d5c258e2d17bec573e68221d23a9.jpg

 

White Connector.jpg

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The solenoids are the key. Back in the days of the old XJ Forum (the predecessor of NAXJA) there was a member named (IIRC) Frank Swigert who had an XJ 4.9L engine and AW4 transmission in a Hornet station wagon. He had the tranny wired up to a 6-position rotary switch so he could control shifting manually just by turning the knob. Once he had it in overdrive (4th gear), the next step on the knob locked the torque converter.

 

That's why the FSM for the AW4 starts out by having you pull the fuse for the TCU and test drive by shifting manually. If that works, the tranny works, and you look for electrical problems.

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Check the solenoids in the cab, via the TCU to tranny connector.  No need to drop the pan, FWIW.  If you get a bad reading that is consistently bad, open the bottom and the solenoids are 1 bolt easy to replace...the hardest part being removing the trans pan.  You also should check the connectors at the firewall to see that they're plugged in, clean etc. 

 

Take that opportunity to change the filter, gasket and fill with nice fresh Dex III or better.  No ATF-4.   IMHO

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28 minutes ago, 91green said:

Dropped the trans pan and pulled each of the three solenoids and checked then to make sure the actuate using a car battery and they all "clicked" the same

 

You could have applied 12V and GND at the connector pins and checked for the solenoid clicks w/o pulling the pan, but at least you've seen them up close and personal now.  :grinyes:

 

Last thing I can think of:  Check for 12VDC on the TCU connector pins D14 (RED wire - battery 12V) and D16 (YEL wire - 12V IGN).

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