What it means
The second input or turbine shaft speed sensor returns no usable signal. Used on transmissions with redundant input speed sensing for closed-loop ratio control.
At a glance
- Usually lights the check-engine light
How it works
Input or turbine shaft speed sensor B detects how fast the transmission’s input shaft is turning, giving the control module a second speed signal for ratio control. The module sets P2765 when this sensor’s circuit does not provide a usable signal.
Common causes
Most likely first.
- Open sensor element or broken signal wire
- Corroded sensor connector
Symptoms
- Check-engine or transmission warning light on
- Harsh or delayed shifts
- Speedometer or gear indication may behave erratically
- Transmission may enter limp mode
How to diagnose it
- Record freeze-frame data and check live input-speed readings to see when sensor B stopped reporting.
- With the ignition off, inspect sensor B’s connector for corrosion, loose fit, or damaged terminals.
- Trace sensor B’s wiring to the transmission control module and look for a break, pinch, or chafe.
- Check the sensor B circuit for continuity and shorts using the vehicle wiring diagram.
- Test sensor B and its signal while the shaft turns, following the manufacturer's specification.
Common fixes
- Clean and secure a corroded or loose sensor B connector.
- Repair an open or damaged sensor B signal wire.
- Replace the failed input/turbine speed sensor B.
- Repair a verified fault in the circuit connection at the control module.
Can I keep driving?
If shifts are harsh, delayed, or the transmission enters limp mode, avoid high speeds and heavy loads and arrange prompt diagnosis. Continued driving with unreliable input-speed data can worsen shift quality and transmission wear.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.