A faulty input/turbine shaft speed sensor B that internally shorts or fails to produce a proper signal; Damaged or corroded wiring harness between the sensor and the transmission control module; An open circuit or high-resistance connection in the sensor's signal or ground circuit; A short to voltage on the signal wire, often from chafed insulation against a power wire; Contaminated or low transmission fluid that affects sensor operation; A failed transmission control module, though this is less common; Loose or damaged sensor mounting that changes the air gap and signal strength

DTC codes / P07xx · Transmission / P07C2

P07C2Input/Turbine Shaft Speed Sensor B Circuit High

Q: What does code P07C2 mean?

Input/Turbine Shaft Speed Sensor B Circuit High. P07C2 indicates that the transmission control module has detected an abnormally high voltage on the signal circuit for the input or turbine shaft speed sensor B, which is the sensor that reports how fast the transmission input shaft is turning. The computer expects the sensor's signal voltage to stay within a specific range, and a sustained high reading tells it that the circuit is likely open, shorted to power, or that the sensor itself has failed.

P07C2 indicates that the transmission control module has detected an abnormally high voltage on the signal circuit for the input or turbine shaft speed sensor B, which is the sensor that reports how fast the transmission input shaft is turning. The computer expects the sensor's signal voltage to stay within a specific range, and a sustained high reading tells it that the circuit is likely open, shorted to power, or that the sensor itself has failed.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaTransmission

Symptoms you may notice

Illumination of the check engine light or transmission warning light, often with no other noticeable symptoms
Harsh or delayed gear shifts as the transmission loses accurate input speed data
The transmission may enter limp mode and stay in a single gear
Incorrect or erratic speedometer readings on some vehicles that share the signal
Poor fuel economy or unusual engine rpm behavior during acceleration

Common causes, most likely first

A faulty input/turbine shaft speed sensor B that internally shorts or fails to produce a proper signal
Damaged or corroded wiring harness between the sensor and the transmission control module
An open circuit or high-resistance connection in the sensor's signal or ground circuit
A short to voltage on the signal wire, often from chafed insulation against a power wire
Contaminated or low transmission fluid that affects sensor operation
A failed transmission control module, though this is less common
Loose or damaged sensor mounting that changes the air gap and signal strength

How to diagnose and fix it

Use a scan tool to read the live data for input shaft speed and compare it with output shaft speed to confirm the fault
Visually inspect the sensor, its connector, and the wiring harness for damage, corrosion, or loose pins
Check the sensor's resistance and signal output with a multimeter or oscilloscope according to the manufacturer's specifications
Test the signal circuit for a short to voltage and for continuity to ground with the key on and off
Replace the input/turbine shaft speed sensor B if testing shows it is out of specification
Repair or replace any damaged wiring or connectors found during testing
Clear the codes and perform a road test to verify the repair and ensure the code does not return

What a high voltage reading really means

A high voltage code often points to an open circuit or a poor ground rather than a failed sensor, so resistance checks on the ground side are just as important as the signal wire.
Transmission fluid that is low or contaminated with debris can cause the sensor to produce an erratic signal that sets this code without any wiring fault at all.
Some vehicles use the same input speed signal for the speedometer, so a faulty sensor can cause dashboard speed errors that mislead diagnosis toward the instrument cluster.
A short to voltage on the signal wire can be intermittent and only appear when the engine is running or the harness is moved, so wiggle tests are essential.
Replacing the sensor without checking the air gap or mounting surface can lead to a repeat code if the new sensor is not seated correctly.

Can I keep driving with P07C2?

You can usually drive the vehicle to a repair shop, but avoid heavy acceleration or long trips because the transmission may enter limp mode and shift harshly. If the vehicle feels unsafe or refuses to shift, stop driving and have it towed.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.