Damaged or chafed wiring in the motor torque sensor circuit, causing a short to voltage; Faulty motor torque sensor, internally shorted or failing to produce a correct signal; Poor electrical connection at the sensor or control module connector, such as corrosion or loose pins; Failed hybrid control module, though this is less common and should be diagnosed last; Water intrusion or contamination in the sensor or connector, leading to abnormal voltage; Aftermarket accessories or improper repairs that tap into the sensor circuit

DTC codes / P0Axx · Hybrid propulsion / P0A20

P0A20Motor Torque Sensor Circuit High

Q: What does code P0A20 mean?

Motor Torque Sensor Circuit High. P0A20 indicates that the hybrid or electric vehicle control module has detected an abnormally high voltage signal from the motor torque sensor circuit, which measures the actual torque output of the electric motor. The computer expects the sensor's signal to stay within a specific voltage range, and a high reading means the circuit is either receiving too much voltage or the sensor is reporting a torque value that is physically impossible.

P0A20 indicates that the hybrid or electric vehicle control module has detected an abnormally high voltage signal from the motor torque sensor circuit, which measures the actual torque output of the electric motor. The computer expects the sensor's signal to stay within a specific voltage range, and a high reading means the circuit is either receiving too much voltage or the sensor is reporting a torque value that is physically impossible.

SystemPowertrain

Code typeGeneric (all makes)

SeverityHigh

Fix difficultyProfessional

AreaHybrid propulsion

Symptoms you may notice

Illumination of the check engine light or hybrid system warning light
Reduced power or limp mode, as the vehicle limits motor output to protect the system
Often no symptoms besides the warning light, especially if the fault is intermittent
Hesitation or jerking during acceleration or deceleration
Inability to engage or maintain electric-only driving mode
Possible stalling or failure to start in severe cases

Common causes, most likely first

Damaged or chafed wiring in the motor torque sensor circuit, causing a short to voltage
Faulty motor torque sensor, internally shorted or failing to produce a correct signal
Poor electrical connection at the sensor or control module connector, such as corrosion or loose pins
Failed hybrid control module, though this is less common and should be diagnosed last
Water intrusion or contamination in the sensor or connector, leading to abnormal voltage
Aftermarket accessories or improper repairs that tap into the sensor circuit

How to diagnose and fix it

Use a scan tool to retrieve all stored codes and freeze-frame data, then clear the code and test-drive to see if it returns immediately or intermittently
Visually inspect the motor torque sensor, its wiring, and connectors for damage, corrosion, or loose pins, and repair as needed
Measure the sensor reference voltage and signal voltage with a digital multimeter, comparing to manufacturer specifications
Perform a wiggle test on the harness while monitoring sensor voltage to detect intermittent shorts
Check for technical service bulletins (TSBs) or known issues for the specific vehicle make and model
If the sensor signal is out of range and wiring is good, replace the motor torque sensor and recalibrate if required
As a last resort, diagnose the hybrid control module for internal faults, following the manufacturer's diagnostic flow chart

Before you replace the torque sensor

A high voltage reading on the torque sensor circuit is often caused by a short to voltage in the harness, not by a failed sensor, so always check for rubbed-through wires near hot or moving components first.
Intermittent P0A20 codes can be set by a loose ground connection at the hybrid control module, which raises the reference voltage and skews the sensor signal.
Some vehicles set this code when the 12-volt auxiliary battery is weak or failing, because low system voltage can cause the control module to misinterpret sensor inputs.
After replacing the motor torque sensor, some models require a relearn or calibration procedure with a factory-level scan tool; skipping this step can cause the code to return immediately.
Do not assume the hybrid control module is bad just because the code persists after sensor replacement; check for aftermarket wiring or accessories that may be back-feeding voltage into the circuit.

Can I keep driving with P0A20?

Driving with P0A20 is not recommended because the vehicle may enter limp mode or lose power unexpectedly, increasing the risk of a collision. If you must drive to a repair shop, keep speeds low and avoid heavy acceleration or high-load conditions, and have the fault diagnosed as soon as possible.

Tools that help

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