[V8] 1990 V8 auto transmission issue

[Tony and Lillie]

Solonoid failure is somewhat rare, but far from unheard of in these transmissions. The multifunction sensor will cause problems immediately when the car is pluued from park. When they get bad enough, the car will even remain in limp mode upon startup. So, no, that does not sound like your issue.

I unfortunately do not have any direct experience with that, but would be ohming out the harness if it were in my shop. There is a harness that is internal in the trans (the one I suspect was replaced) and one from the trans to the TCU. Beyond that it's going to be either a TCU failure or an internal trans issue (I suspect this one). If that is the case, you are either looking at sourcing a used replacement, having yours rebuilt, or converting the car to a manual transmission.

Keep us updated, and BTW, where are you located?

HTH,
Tony
  ----- Original Message ----- 
  Subject: [V8] 1990 V8 auto transmission issue


  Tony,

   

  I have a 1990 V8 (110K miles) that shifts down to limp mode at about 2K RPM if you let up on the accelerator.  

   

  According to the mechanic the code was a trans solenoid failure.  He checked with ZF and apparently was told that solenoid failure is very rare and that it was likely a wiring harness problem.

   

  The pan was dropped and the solenoid positions were changed and the external wiring harness was replaced with another used one.  The problem still exists.  I haven't yet taken it back in to see what the code is now.

   

  Am I on the right track or should I be looking at the multifunction sensor per your comments below?

   

  I love this car and it runs great other than the downshift problem.  I just had the entire rear suspension redone (re-bushed, shocks, & brakes) and new front brakes with new UFO rotors so I would hate to bail at this point.

   

  Thanks.

   

  Bill