93 lesabre will not shift into drive or overdrive

[buick lesabre bill]

Transmission problem
1993 Buick Lesabre V6 Front Wheel Drive Automatic 210000 miles
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My 93 Lesabre will not shift into drive or overdrive, checked codes and 39 came up. I know this is the TCC circuit and I heard that I could disable the the solenoid. The only electrical plug I find on the transmission has 4 wires on it and I don't know which one to cut. Any information at all would help. I have already changed the fluid and filter and it didn't look that bad. Also could this have anything to do with the ABS?

[maxwedge]

Welcome to AF. Not shift into drive or o/d, explain this further, what you say means it won't move in dr.?

[buick lesabre bill]

everything works just like it is supposed to when you sart off until you get going fast enough for the transmission to shift into drive, it stays in second and will not go any higher.

[maxwedge]

I would have it scanned for trans solenoid functions, possible it is in limp mode due to an internal failure, this assumes the fluid is not burnt, it is full and the modulator has vacuum to it.

[buick lesabre bill]

have you ever heard of disabling the tcc solenoid when this occurs? if so, how would i go about doing that? i have changed the fluid and filter and it wasnt too bad.

[imidazol97]

Originally Posted by buick lesabre bill

have you ever heard of disabling the tcc solenoid when this occurs? if so, how would i go about doing that? i have changed the fluid and filter and it wasnt too bad.

I finally did it. I dug out my 93 Service Manual.

1-2-2-1 shift only
1st and 2nd gear only
Possible codes 26 or 56 Quad driver module circuit
36 transaxle shift control problem

Inspect component: "B" shift solenoid for "ON" familure

foreign material in solenoid
PCM signla grounded
Pinched solenoid return wire to ground

Info:

B shift solenoid
is electronically controlled by the PCM
is an electronic normally open exhaust value
when actived, it redirects the exhausting fluid to act upon the 1-2, 2-3, and 3-4 shift valves.
there are two diagnostic trouble codes one elctrical and one mechanical
and more'''

Checking without transmission test box:

key off
disonnect engine wiring harness at transaxle
set DVM to ohms position
check resistance of TCC shift solenoid circuit
A. ground positive probe of DVM to transaxle pin "E"
B. Ground negative probe of DVM to transaxle piin "G"

If 25-50 ohms
then disconect PCM green connector
find solenoid wire from PCM
check continuity between Pin "G" (engine harness) and PCM (green connector wiring harness pin

OR
if less than 20 or more than 50 ohms
Check internal transaxle wiring harness for opens or grounds
if wiring harness if okay then replace "B" shift solenoid

There is more to this page that I haven't typed in.