Automatic Transmission

This is a 2000 Century 6 cylender automatic, 35000 miles,
This intermittantly shifts very hard both up and down, hot or cold.
The fluid is clear and not burnt.
80% of the time the transmission is fine but 20% of the time there is a problem.
What transmission is in this car?
Does it have a throttle valve cable?
Does it have a vacume modulator?
Does it provide a diagnostic troubleshooting code?
Has anyone had this problem? Any idea what the problem is? I have some automotive experience. Is this something I might be able to fix myself? :banghead:
This is my father-in-laws car and I am trying to help.
THANKS
Jerry Fengler

JERRY
you must hook up the scanner to it, no other wise. in order to know what going on

What transmission is in this car?
4T65E

Does it have a throttle valve cable?
NO

Does it have a vacume modulator?
NO

Does it provide a diagnostic troubleshooting code?
YES

Any idea what the problem is?
YES replace your PCS!

Is this something I might be able to fix myself?
NO! The Trans side cover needs to come off!

I really appreciate talking to someone who is knowlegable in this field. :naughty: I am a Master Mercedez technician and am trying to help my Father-in-law with his Buick car problem. In a couple weeks I need to drive his car up to Conn for him as they are down here in Florida for the winter. We live in Florida but 2 1/2 hours away.

I am unfortunately on a short time schedule and am trying to resolve the problem with the car. :disappoin

CAn you answer these questions?
What is a P.C.S.?
Should a dealer repair it?
Is a transmission repair shop OK?
Do you know the approx. cost for parts and labor?
Is removing the side cover and replacing the P.C.S. a big deal?(ie special tools, adjustments or specific knowledge)
THANKS,
Jerry Fengler

A PCS or a "pressure control solenoid: is used to adjust trans line pressure, it is a duty cycle controlled solenoid.

I would recommend a dealer fixing it but most trans repair shops should be able to do it.

I really don't know the part price but the labor is about 5 hours, so depending on your labor rate will give you a ball park price.

Since your a tech you should be able to handle the job on your own. Really nothing hard to it just takes time. You will have to support the engine and trans because the engine cradle has to be lowered. Lower the cradle enough to remove all the bolts on the side cover of the trans, remove the left axle. Once the side cover is off its right there in the open. Only special tools you need is a engine support. After the PCS is replaced you would need to get a scanner and reset the taps or "trans adapts" which is a shift memory built into the PCM. Any trans shop or GM dealer can do it for you. If you don't reset adapts the trans will not shift right.