# P1811C Transmission Code **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** buick, century\ **Created:** [August 31, 2009, 2:59pm UTC](https://community.cartalk.com/t/p1811c-transmission-code/35885 "2009-08-31T14:59:03Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![sankeny](https://avatars.discourse-cdn.com/v4/letter/s/e36b37/32.png) [@sankeny](https://community.cartalk.com/u/sankeny)\ **Post date:** [August 31, 2009, 2:59pm UTC](https://community.cartalk.com/t/p1811c-transmission-code/35885/1 "2009-08-31T14:59:03Z")
2000 Buick Century with intermittent transmission surges while changing gears. A local mechanic read the computer codes and determined a P1811C code but checked Step 11 of the AllDataPro readout. Inspect transmission for the following: \* 203 accumulator piston seals rolled \* 2-3 accumulator piston and pin missing \* oil pump assembly damaged \* spacer plate and gaskets damaged … etc. P1811 is the Maximum Adjust and Long Shift code on Buick. What does the “C” add? And, does the Step 11 indicate actual internal damage? I have been advised that there’s a gasket easily replaced on the side of the transmission with the Maximum Adjust code, but I’m wondering if this test indicates there’s internal damage and a total repair is needed. Thx.