Maximum Adapt and Long Shift
2002-2007 Buick Rendezvous 3.5L V6 🇩🇪
Description
The TCM has raised hydraulic line pressure to maximum to compensate for excessively worn clutch packs or other internal components. The TCM detected shift times exceeding 0.65 seconds too many times. This is a serious transmission code indicating internal wear. Common on GM front-wheel-drive vehicles with the 4T65E transmission.
Symptoms
- Extremely harsh 1-2 and 2-3 shifts (feels like being rear-ended)
- Check Engine Light
- Hard shifting in all gears
- Shuddering between shifts
- Whining noise from transmission
- Transmission slipping before hard shift
Common Causes
- Worn clutch packs (most common)
- Faulty pressure control solenoid
- Low transmission fluid
- Blocked valve body
- Worn seals causing pressure loss
- Contaminated transmission fluid
Diagnostic Steps
- Check transmission fluid level and condition
- Test line pressure
- Monitor shift times with scan tool
- Test pressure control solenoid
- Inspect valve body for wear
- Check for related solenoid codes
Repair Notes
Change transmission fluid and filter first. If code returns, test pressure control solenoid. In many cases, a transmission rebuild is needed due to worn clutches. A TransGo shift kit can extend life by shortening shift times. Common on Impala, Monte Carlo, Grand Prix, Regal, Century, and Venture.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P1811 on Other Vehicles
Common Questions
What does code P1811 mean on a 2002-2007 Buick Rendezvous?
P1811 stands for "Maximum Adapt and Long Shift". The TCM has raised hydraulic line pressure to maximum to compensate for excessively worn clutch packs or other internal components. The TCM detected shift times exceeding 0.65 seconds too many times. This is a serious transmission code indicating internal wear. Common on GM front-wheel-drive vehicles with the 4T65E transmission.
What are the symptoms of P1811 on a Buick Rendezvous?
Common symptoms of P1811 include: Extremely harsh 1-2 and 2-3 shifts (feels like being rear-ended), Check Engine Light, Hard shifting in all gears, Shuddering between shifts, Whining noise from transmission, Transmission slipping before hard shift.
What causes P1811 on a 2002-2007 Buick Rendezvous?
Common causes of P1811 include: Worn clutch packs (most common), Faulty pressure control solenoid, Low transmission fluid, Blocked valve body, Worn seals causing pressure loss, Contaminated transmission fluid.