I experienced some late shifting from 1st gear to 2nd gear and engine temp rose just past the 12 o'clock normal position and back to normal while idle in PARK, I let the car cool and received a P1811 code.This has only happened the one occurence, car continues to shift normal but still receiving code after codes have been cleared. Anyone familiar with what are the possible fixes for a P1811....Long shift and maximum adaptation limit reached code? I have a 1998 seville sts throwing this code. Also flashes SERVICE TRANSMISSION on information center periodically, it is not coming up everytime the car is drivin. Just about ounce a week.

How many miles on the car? And what does the trans fluid life monitor on the DIC read?

Engine and trans has 98,000 miles, but body of car has 161,000 miles. Trans Fluid was reading 98%. I changed the trans fluid from the pan only, and replaced the the filter screens with new ones..... reinstalled the transpan put new dexron III fluid to the correct level while hot and idling. Screens and pan magnet look good with no build up, but still changed them anyways. The fluid was tarnised slightly, but appeared to still look red. Shortly after still received code.

Thanks for your quick reaponse!

:hmm: Must consult FSM...

OK - this is not simple. The diagnostic in the 1999 FSM is 4 pages long and a lot of scan tool tests. With a 1-2 shift problem it suggests that the line pressure may be too low. It looks ike to inspect most of the items requires disassembly of the transmission. A few things include:

The pressure conrol solenoid is stuck ON
The pressure control solenoid has a broken clamp causing leakage
The clutch plates (431 - 435) are burned or damaged
The piston assembly 2nd clutch is cracked or damaged
The 2nd clutch returen springand retainer assembly are broken or out of position
The 2nd clutch return spring and retainer assembly are broken or out of position

It goes downhill from there. One thing that caught my eye was your use of Dexron III. I think they are up to Dexron VI and I do not know what the correct transmission fluid for these cars is, but if III is not correct your transmission service may have caused this code to be set. P1811 will set the SERVICE TRANSMISSION warning. Need one of the gurus to weigh in here as I cannot find the recommended fluid in the FSM.

I havent received the code for about 10 days now. Seems to be that it is intermittent or had a stuck solenoid. I will just drive it I guess till I receive a code again. Thanks for you help.

DEXRON-III was the original and recommended fluid. DEXRON-VI has now superceded -III and is 100% backward compatible in any ratio or fill to the mark. GM TSB down in Technical, Tips.

I'm in the same boat here.

am getting
P0714 - Transmission Fluid Temperature Sensor Circuit Intermittent

P1811 - Maximum Adapt and Long Shift

could a fluid change be in order, or should I sell the car and get a newer one?
the book price does not justify a tranny rebuild for this steed.
any one else???