88 Ranger 2wd Auto

[fogmikey]

88 2wd Ranger XLT, 2.9, Auto (A4LD) Std cab Long bed. 209K on chassis, approx 95K on a used 2.9 that I just installed. Post engine change: Transmission will no longer shift 3-4, or OD. Also not getting TQ converter lockup. It is throwing codes 86 & 89. Plenty of fluid, runs great, simply doesn't go into OD. A local tranny shop looked at it for a few days, and said they can't find those 2 inputs coming into the trans connector. Pulled and cleaned ECU connectors and reassembled, no help. Swapped in a used apparently serviceable ECU, again no help. OK, is there a sure-fire way to know if I have an internal trans failure or a controlling or electronic issue. Kinda want to drive this truck and I'm gettin frustrated. TIA for your time...

 

[Psychopete]

How does it shift from first into second?

 

[jhammel85]

I'm thinking that it's the vac solenoid on the outside of the transmission for Overdrive. It has vacuum from the engine right?

 

[Psychopete]

There's an additional R/W wire on the trans plug. AOD just has 4 wires for reverse lights and NSS, that A4LD should have 5.

 

[fogmikey]

Thanks for replies...it shifts fine in all gears until it's time to go into OD. I believe the vacuum line is intact on the solenoid, but I will check it. Is the info about the wiring to tell me to make sure I don't have a wire loose?