4L60 guru's..... in here

[FORD RECOVERY EXPERT]

A 97 4wd Tahoe, throwing P0785 only. (Shift/Timing Solenoid Malfunction)
Throws it within 10 secs of startup, even after clearing it, and wont shift from 3rd.

First time I cleared it, it shifted fine for a few miles. Thru all 4, passing gear, everything. But now, you can clear it, and within 10 secs of startup, even if you don't take it out of park, it throws it....

When it does, it won't even manually shift.

I'm reading alot about Ign Swi/ PCM failures, but most all say it should be throwing more codes also, and the cluster should be failing intermittently....



Could it simply be the solenoid??? If so, why would it shift normally after cleared... And how could the PCM know it was bad before you ever take it out of park???????

[Cutlass]

The PCM is constantly checking for feedback from that solenoid, therefore it can set at anytime. I don't think your problem relates the ignition switch because that usually causes a bunch of other trans codes to store.
Usually this code relates to the 3-2 shift solenoid itself or the wiring to/from it. best bet is to pull the pan, check the wiring inside the trans, and replace the 3-2 shift solenoid. You could also do a quicky inspection of the wiring external to the trans for obvious burns/chaffing/broken wiring

[Darthscooby1001]

Gent's,

I have the same problem as this and wonder before I take my car to the garage if your advice solved the problem, i.e. changing the solenoid?

Thanks