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Derek Werner
Derek Werner, Buick Technician
Category: Buick
Satisfied Customers: 137
Experience:  ASE Master Technician, L1 Advanced level specialist
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My Buick century was recently put under a diagnostic and it

Customer Question

My Buick century was recently put under a diagnostic and it came up with max adapt and long shift codes. I want to know what this means and how to fix it
JA: How old is the transmission? Have you noticed any leaking?
Customer: There is no leaking and the car itself is 10 years old, its a 2005 and it was recently bought in april
JA: What year is your Century?
Customer: 2005
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: No i was looking to bring it into a car place than can fix it for me and i have gone to transmission shops and they want to rebuild the transmission but my problem does not happen all the time and i was hoping that maybe it is something electrical or computer controlled that is causing the problem
JA: Anything else you think the mechanic should know?
Customer: The transmission hard shifts from time to time
Submitted: 12 months ago.
Category: Buick
Expert:  Derek Werner replied 12 months ago.

Hello and thanks for using JustAnswer!

I am Derek, an ASE master certified technician and I will be happy to assist you with your Buick.

How many miles are on your vehicle?

Is the transmission fluid full and clean?

Customer: replied 12 months ago.
66,600 and my fluid levels are good i recently had them check for good measure
Expert:  Derek Werner replied 12 months ago.

ok great, What has likely happened is the pressure control solenoid inside the transmission is starting to fail. The solenoid controls the Hydraulic line pressure inside the transmission. If the pressure is low it will cause an intermittent harsh shift and set a P1811 fault code. A max adapt and long shift code indicates an excessive time delay between gears when the transmission shifts. If the time is above a specifically programmed amount the code sets.

With the miles that are on your car, it is a very safe bet the internals of the transmission is still ok.

Has the transmission pan been removed and checked for excessive debris? Excessive clutch material or metal in the bottom of the pan will indicate it needs to be rebuilt.

If excessive debris in the pan is not found it is very likely the transmission pressure control solenoid should be replaced, and will fix the concern.

Replacing the PC solenoid or pressure control solenoid is a big job. The side cover known as the valve body cover needs to be removed to replace the solenoid.

Is this something you might try replacing yourself?

Customer: replied 12 months ago.
No the transmission pan has not been put down i should have done it last week while i was at the shop but i will get this done probably tomorrow. Could you estimate how much it would be to fix the pressure control solenoid? It is an random problem, sometimes it will do it and other time it will hard shift.
Expert:  Derek Werner replied 12 months ago.

Ya it is a very common problem for your model year of the vehicle, and this code normally will not even turn on the check engine light. Normally the transmission will work for many years with this type of code set.

What happens is the solenoid starts to get worn and will stick, when it sticks you feel the harsh shift like you are describing.

I am looking up the labor time for the job now.

Customer: replied 12 months ago.
Okay thank you very much sir
Expert:  Derek Werner replied 12 months ago.

Not a problem, sorry to hear you are having transmission issues but with the low miles i am very certain you will be just fine with replacing the solenoid. The engine in your car is very reliable and should be a good vehicle for a long time.

Labor to replace the solenoid is 4.6 hours. This time, is from ALLDATA. Normal shop rates vary depending where you go. You should expect to pay around 80 to 100 dollars and hour.

The solenoid is cheap it can be found for around 30 to 50 dollars. I would make sure you buy a quality ACDelco part and not an aftermarket solenoid.

Customer: replied 12 months ago.
Okay sir thank you so much for your help I am giving you five stars for all you have done, I have been to so many places and haven't been able to find an answer to my problem you have now given me an answer thank you once again
Expert:  Derek Werner replied 12 months ago.

Thank you I am glad i could help!

If you have any other questions feel free to ask.



Customer: replied 12 months ago.
What if I was to get this job done at a Midas shop, how much will it cost me?
Expert:  Derek Werner replied 12 months ago.

Depending on the shop rate and the cost they charge for the part I suspect you will be paying around 500 to 600. I would call around some shops in your area to get a good price.

Honestly, I would stay away from Midas, at least around my area where I live in Montana they are not known for doing great work. A transmission shop would be a good bet since they do this kind of work all the time.