What it means
The third intermediate shaft speed sensor produces no pulses while the shaft is known to be turning.
At a glance
- Usually lights the check-engine light
How it works
Intermediate shaft speed sensor C reports how fast the transmission’s third monitored intermediate shaft is turning, using pulses from a rotating tone wheel. The transmission control module compares that signal with other speed information and sets P2751 when the shaft is turning but sensor C produces no pulses.
Common causes
Most likely first.
- Tone wheel sheared or rotating loose
- Sensor failed completely
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
- Use a scan tool to save freeze-frame data and check live speed readings for intermediate shaft sensor C alongside other transmission speed readings.
- Check whether the code returns while the shaft is turning, since a zero reading only matters when the module expects sensor C to detect rotation.
- Inspect sensor C, its connector and nearby harness for damage, loose connections, fluid intrusion or pushed-back pins.
- If the sensor is accessible, inspect its tone wheel for broken teeth, shearing or looseness that could prevent pulses.
- Test sensor C and its circuit using the manufacturer's procedure to distinguish a failed sensor from a wiring fault.
Common fixes
- Reconnect or repair a loose or damaged sensor C connector.
- Repair damaged wiring in the sensor C circuit.
- Replace a sheared or loose tone wheel.
- Replace intermediate shaft speed sensor C if its signal test confirms failure.
Can I keep driving?
Limit driving, especially if shifts are harsh or delayed, the speed or gear display is erratic, or the transmission enters limp mode. Continued driving with unreliable shaft-speed information can worsen shift quality; stop if the transmission slips or loses drive.
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.