I have done tons of reading online and it appears there is few ways to go about fixing it (some never do or never post back). I have heard of the TPS, MLPS, rear ABS pumpkin sensor, dash cluster and even the main ECM.

Here is what I have a going on, it's a 1994 E350 5.8L E4OD 197k on the clock pulling around a small shuttle bus. No flashing O/D, No codes, TPS is new, did a pan drop looked good in there, replaced rear ABS pumpkin sensor. ABS light is on but not related to trans problem. Let me explain, meaning it must be some kind of hard fault it's on from the sec I turn the key on from the battery disconnect, and the trans will shift silky smooth with it on. I have the rare three/ four wheel ABS on this rig.

The trans will start to have a rough engagement in D and R and 1-2 2-3 Shifts. Pretty much as fast as it takes to reach normal temp, Shift into 3-OD most of the time I can't feel them, but when its warm it's a quick firm shift but not alarming. When cold the trans shift's like butter in all gears and during D-R, can't even feel it, so I think that would rule out anything but an electrical problem. I disconnect the battery and next day shifts are back to normal.

What is my likely suspect to go after, Spedo is steady at speeds under 50 MPH I did notice some very minor bounce around 65, would doing a 2nd drop and the TC help anything, fluid looked ok before my pan drop. MILP looks factory and the pins look clean no mud or green crusty

 

 

I think the PCM is seeing a problem with the signal from the ABS, or lack of signal, and that's causing a failure mode that causes harsh shifts.

 

Ok how do I go about fixing the ABS system? If it needs front wheel sensors do they even make them anymore? I can't find them anywhere, How do I pull codes from the ABS? I see a round plug under the bus by the ABS computer that looks like a data port but northing I know of plugs in there