I have a 94 4x4 with 158xxx on it . I am getting a KOEO code of 566 and CM codes 157 , 158 . The truck won't shift into OD> So I dropped the pan on the tranny to replace the 3-4 shift solenoid only to find that the prior owner had someone swap in a valve body from an earlier A4LD into it , so only one solenoid for TCC. Has any body ever seen this before and why would you want this, it makes 3=4 shift hydrostatic instead of electronic. so my question is how am i getting this code possible ECM ?

 

Welcome to the forum

Early A4LDs only had TCC solenoid, 3/4 shift was added in late '80's
If it only has 2 wire plug in then it is an older A4LD, if 3 wire then it is later model

If someone removed the 3/4 shift solenoid from a dual solenoid A4LD I don't see it shifting into OD at all, but maybe with older valve body, never tried that before

Yes the 1994 computer would look for two solenoids connected, 4.0l only came with dual solenoid A4LD, so with no 3/4 shift solenoid you would get the code

I would clean the MAF sensor first, as far as the other 2 codes, also make sure MAF connector is clean and dry

 

I should have mentioned that the truck has only given this code just recently and it drove fine with no problems before. The trans was rebuilt thru the prev owner and when I dropped the pan this weekend what I found was that the connector had been altered to accept only one solenoid and the valve body is from an early A4LD. I think the mod was done by someone who at the very least knew what they were doing because there are also parts in the valve body that have been added such as check ball. I believe the early valve body only has 5 check ***** in it this one has 6. What puzzles me is that the truck ran fine before the CEL came , it shifted into all 4 gears and OD.