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Chevrolet Repair/4T65E Transmission

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Question
Hey Tom,
I periodically (once every month) get a P1811 code on my 02 Grand Prix.  I already replaced the pressure control valve/solenoid but it didn't seem to help much.  Otherwise the trans shifts great and the fluid and filter seem reasonably clean.  My only objection is the harsh shifting that occurs after
the code sets.

Is there any way to access the PCM's parameter settings and shut the "Max Line Pressure" feature off ???  In my opinion, this is a half-baked feature that should never have been implemented.  It's only natural that the shift duration will increase, as the car ages, thus setting the code and the "Max Line Pressure" command.  I am convinced that in many cases, the transmission does not require a rebuild or valve replacement.  GM should offer a PCM re-flash as an alternative to expensive transmission service.

Are there any similar options available for this common problem?

Regards,
Colin

Answer
HI COLIN,WELL I KNOW WHAT YOU ARE TALKING ABOUT HERE, AND YES THERE IS A WAY TO [REMAP THE PCM]
THE PROBLEM IS >>> YOU NEED TO FIND SOMEBODY WITH THIS SOFTWARE TO DO SO..THERE IS A SPEED SHOP IN MY AREA THAT CAN DO THIS REMAPPING..I DO NOT KNOW WHERE YOU LIVE BUT IF IT IS IN A BIG CITY AREA I AM SURE THERE IS A SPEED SHOP THAT CAN DO THIS FOR YOU..THEY CAN CHANGE THE SHIFT POINTS THROUGH THE SOLENOIDS OF THE VALVE BODY...CALL AROUND TOWN AND IF SOME SHOP HAS A DYNO YOU CAN BET THEY HAVE THIS SOFT WARE TO DO SO..NO REGULAR REPAIR SHOP WILL HAVE THIS TYPE OF SOFTWARE... GOOD LUCK TO YOU..TOM  

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TOM SHEETS

Expertise

PLEASE READ ALL OF THIS BEFORE ASKING ANY QUESTIONS. IF THIS CHEVY SECTION IS MAXED OUT.YOU CAN REACH ME IN THE OLDS/BUICK SECTION. Will answer questions from 6:00am to 10:00pm all days [EST][[[ NO DIESEL OR PAINT QUESTIONS]]] will answer all 1965 to present QUESTIONS ON ALL GM'S on mechanics of these cars. Keep in mind i am not there in person i am going on what you are telling me !! PLEASE IF ASKING A QUESTION GIVE ME AS MUCH INFO AS POSSIBLE. THE MORE THE BETTER. SUCH AS YEAR,MAKE,MODEL,ENGINE SIZE. THIS WILL HELP ME HELP YOU. I will not be able to answer all questions because of some situations that i would really need to be there and see things for myself,such as electrical issues. In many cases i would need wiring diagrams. I can also give you an estimate on what the cost would be at our repair shop as an idea to help you. Keep in mind that my answer is ONLY MY ADVICE,ck with your mechanic as well.. >> THANK YOU, TOM..

Experience

I have been a ASE certified master mechanic for over 30 years and certified IN ALL 8 CATEGORIES,[engine repair,engine performance,auto trans,manual trans,clutches,steering and suspension,brakes,electrical systems,heating and air/cond. I am also a state CERTIFIED inspector for over 30 years. I do computer work [pcm]fault codes,pcm flashing,state inspection monitor readiness,repairs on exhaust,fuel service,[injection and carburetor,] charging system problems, running issues,alignments,frame problems,tire balance,struts and of course standard and anti-lock brakes.

Organizations
nys state auto repair industry and ase group.

Publications
N/A

Education/Credentials
high school,4 years of tech school,and many many hours of auto training with many gm classes and aftermarket training classes..

Awards and Honors
ASE MASTER TECH CERTIFIED IN ALL 8 CATEGORIES.NYS INSP LICENSE AND A/C CERTIFIED

Past/Present Clients
MANY CUSTOMERS IN OUR BUSY SHOP.

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