1998 Pontiac Trans Sport. Changed the
transmission fluid  filter several years ago. Added
Lucas transmission treatment.
Question: The transmission sometimes comes out
of gear while stopped at a traffic light or stop sign.
It is very random. It may not happen for several
days or weeks and sometimes it can happen twice
in one day.

When the problem occurs, it sometimes takes a
minute or two of shifting back and forth from Drive
to Park to Drive before it starts going again. The
transmission never slips or comes out of gear
while the van is moving. It only seems to occur
after the van stops at a stop sign or traffic light.

First, be sure to check fluid level and condition.
There is nothing external or electrical that can
cause this. May have a problem in the forward
clutch, forward band apply, or a rolled seal.In any
of these cases, removal and disassembly would
be needed. May be time for an overhaul.
You could try to have a transmission flush service
done and see if it helps.
2003 Pontiac Grand Prix Check Engine Light code transmission
Question = I have a 2003 Pontiac Grand Prix with 84,000 miles
on it. My Service Engine Soon light just came on about a month
ago and when it did my cruise control stopped working as well.

I can feel it has trouble shifting and I have hooked it up to a
machine that AutoZone has to check my problem and it says its
a transmission module (P0753).  We have asked others who
say that it probably isn't the problem because they have never
heard of one of those going out and it's probably a wiring issue.
Can you tell me what you think it might be?

This codes refers to the 1-2 shift solenoid. Be sure to check all
fuses first. Specifically the "TCC" fuse in the
underhood fuse block. If that is ok, 2 things possible.

Either you have a connector problem at the 20-way
transmission case connector causing this code, or the solenoid.
The solenoid is on the valve body in the side case of the trans.
Suggest disconnecting transmission connector with key off, look
at all terminal, pull the harness a little so as to change its
position, then plug it back in. Clear the codes and drive it.
Pontiac Transport Shifting Problems And Code P0753

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