1987 AW4 shifting help needed

[MOBBiN]

I have an shifting(?) issue when putting my truck into drive. It feels like it's starting in 3rd or 4th. It barely moves and feeling like it's going to dog down and die. When starting all the way down in 1st/2nd it takes off just fine. I've already freshed the grounds on the block. My next idea was to replace the TCM. Any other ideas?

[HOrnbrod]

Check the 10A inline TCU fuse under the passenger side dash to verify the TCU is receiving 12V. On a Renix it's in the TCU harness; reach up by the heater box and and pull it down and check the fuse in the fuse holder. Also verify there is 12V IGN SW voltage on the wire. Also there should be a 7.5A TRANS fuse in the fuse block - check it also.

[MOBBiN]

The TCM looks to be full of mud/silt

 

 

 

Got it all cleaned up and tested the plug

 

What are the wires the the twist caps on them for....

[MOBBiN]

After cleaning and testing it's still got the same issues

[cruiser54]

TCU is likely fried then.

[MOBBiN]

Going to the wrecking yard in a couple hours to get a new one. Also going to use this guide to make sure I'm getting power to the TCM

 

https://files.acrobat.com/a/preview/10ffb0ce-2e30-42ea-ac0c-6e10b1e43b60

[omega_rugal]

your TCU is probably dead but try powering the solenoids manually to see if the tranny shifts fine that way...

[MOBBiN]

New TCM fixed the issue. Thanks everyone