Fault code P1911 – a step-by-step guide to diagnosing and fixing it

Error code P1911 is displayed and the check engine light is on - what does this mean?

The DTC P1911 is recognized by the OBD system when a problem is detected with the transmission control unit or the torque converter clutch system. This manufacturer-specific error code mainly affects the automatic transmission and its electronic control unit. This trouble code can have slightly different meanings for different vehicle manufacturers, but generally refers to problems in the transmission area.

What causes can this error code have?

• Defective transmission control unit (TCM)
• Damaged cable connections to the transmission
• Faulty torque converter clutch
• Defective transmission sensors
• Worn solenoid valves in the transmission
• Insufficient or contaminated transmission oil level
• Loose or corroded plug connections
• Defective transmission oil pump
• Mechanical damage to the transmission

What symptoms occur in parallel with error code P1911?

• Shifting problems: The automatic transmission shifts jerkily or with a delay
• Emergency running program: The transmission switches to safety mode
• Loss of power: Noticeable reduction in engine power
• Unusual noises: Rattling or grinding from the transmission area
• Increased fuel consumption: Significantly higher consumption than normal
• Starting problems: Vehicle is difficult to start
• Engine stuttering: Unsteady engine running at different engine speeds

How can the problem with error code P1911 be rectified?

• The repair requires a systematic approach to identify and rectify the root cause.
• Check the transmission oil level and quality, change or top up if necessary, as contaminated or insufficient oil is often the cause
• Check all electrical connections to the transmission for corrosion and tight fit, repair or replace damaged cables
• Read out the transmission control unit (TCM) with a professional diagnostic device and have it replaced if defective
• Test torque converter clutch for proper function and replace completely if worn
• Clean the solenoid valves in the transmission or replace with new parts if irreparably damaged
• Check transmission sensors individually and replace defective sensors with original spare parts
• In the event of mechanical transmission damage, consider a complete transmission overhaul or a replacement transmission