Open circuit or high resistance in the motor temperature sensor wiring; Corroded, loose or damaged connector at the motor or inverter; Failed motor temperature sensor (internal open circuit); Signal wire shorted to a voltage supply; Chafed or damaged harness near the motor, brackets or moving parts; Fault inside the inverter or motor control unit sensor input; Outdated control unit software where the manufacturer lists it as a known cause.

P0A33

Drive Motor B Temperature Sensor Circuit High.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
A: AreaHybrid propulsion
33: FaultThe specific fault in that area

What it means

P0A33 means the control unit monitoring drive motor 'B' in a hybrid or electric vehicle saw the temperature sensor signal voltage higher than its valid range. On a typical thermistor circuit this suggests an open circuit, a poor connection or a short to supply, so the motor temperature cannot be trusted. The layout, sensor type and which motor is 'B' depend on the model.

Symptoms

Warning lamp on, such as a hybrid system or powertrain fault light
Reduced power or limp mode to protect the motor
Reduced or disabled electric drive or regeneration
Motor cooling fan or pump running harder than expected
Fault may come and go with vibration or temperature changes

Possible causes

Open circuit or high resistance in the motor temperature sensor wiringlikely
Corroded, loose or damaged connector at the motor or inverterlikely
Failed motor temperature sensor (internal open circuit)likely
Signal wire shorted to a voltage supplypossible
Chafed or damaged harness near the motor, brackets or moving partspossible
Fault inside the inverter or motor control unit sensor inputrare
Outdated control unit software where the manufacturer lists it as a known causerare

How to diagnose

Read all stored and pending codes and note the freeze frame data, including motor temperatures and whether the fault is current or intermittent.
Check for related codes for other motor temperature sensors, inverter faults or cooling system faults, as these point to a shared cause.
Check live data for motor B temperature. An implausibly low or fixed value, or one that jumps about, suggests an open circuit or sensor fault.
Visually inspect the harness and connectors between the motor and the inverter or control unit for damage, corrosion, moisture, or bent or pushed-back pins. Only a qualified technician trained in high-voltage systems should work on these vehicles, following the manufacturer's isolation procedure.
Gently wiggle the harness with live data on screen to see if the reading changes or the fault appears.
With the system safely isolated and the connector disconnected, test the sensor resistance against the manufacturer's temperature specification.
Test the signal and reference wires for continuity, short to supply and short to earth, following the wiring diagram for the model.
Check whether any software updates or technical bulletins apply to this code on the vehicle.

How to fix

Repair or replace damaged wiring, and secure the harness away from heat and abrasion.
Clean, repair or replace corroded or damaged connectors and terminals.
Replace the motor temperature sensor if its resistance is out of specification or open circuit, following the manufacturer's procedure.
Repair any short to supply found in the signal circuit.
Replace or repair the control unit or inverter only after the wiring and sensor have been proven good.
Apply a manufacturer software update only if it is listed as a fix for this fault.

Can I keep driving?

Medium severity

The car may be driven carefully for a short distance, but power may be limited and the motor temperature is not being monitored properly. Have it repaired soon, and stop if warnings escalate, power drops sharply or you notice overheating.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.