Loose, corroded or damaged connector at the inverter voltage sensor circuit; Chafed, broken or intermittently shorting wiring in the sensor signal, supply or ground circuit; Faulty inverter voltage sensor, which may be built into the inverter assembly on some models; Low or unstable 12 V supply or poor earth affecting the control unit and sensor readings; Internal fault in the inverter or motor control module; Outdated control unit software where the manufacturer has a known fix; Moisture or coolant ingress into the inverter or its connectors.

P0D31

Drive Motor A Inverter Voltage Sensor A” Circuit Intermittent/Erratic.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
D: AreaReserved
31: FaultThe specific fault in that area

What it means

P0D31 is a generic powertrain code meaning the control unit has detected an intermittent or erratic signal from the voltage sensor in the drive motor A inverter circuit. It is set when the sensor reading jumps, drops out or does not behave plausibly compared with expected values or other voltage readings. It applies to hybrid and electric vehicles, and the exact sensor location and strategy depend on the model.

Symptoms

Hybrid or EV system warning light on the dashboard
Malfunction indicator lamp illuminated
Reduced power or limp mode
Intermittent loss of drive or the car refusing to go into Ready mode
Poor or inconsistent regenerative braking
Fault that comes and goes, often with bumps or temperature changes

Possible causes

Loose, corroded or damaged connector at the inverter voltage sensor circuitlikely
Chafed, broken or intermittently shorting wiring in the sensor signal, supply or ground circuitlikely
Faulty inverter voltage sensor, which may be built into the inverter assembly on some modelspossible
Low or unstable 12 V supply or poor earth affecting the control unit and sensor readingspossible
Internal fault in the inverter or motor control modulepossible
Outdated control unit software where the manufacturer has a known fixrare
Moisture or coolant ingress into the inverter or its connectorsrare

How to diagnose

Read all stored and pending codes and note any related inverter, motor, battery or 12 V supply codes.
Review freeze frame data to see vehicle speed, temperature and system state when the fault set.
Check the 12 V battery condition and charging, and inspect main earth connections, as low voltage can cause erratic readings.
Visually inspect the inverter sensor wiring and connectors for chafing, corrosion, moisture, bent pins and poor retention, following the manufacturer's high voltage safety procedure.
With the fault active, watch live data for the inverter voltage reading and look for spikes, dropouts or readings that disagree with the battery voltage.
Wiggle test the harness and connectors while monitoring live data to reproduce the intermittent fault.
Test the sensor circuit for continuity, short circuits and supply voltage using the manufacturer's wiring diagram, only after the high voltage system is isolated by a qualified person.
Check for applicable software updates or technical bulletins for the specific model.

How to fix

Clean, repair or replace faulty connectors and terminals in the sensor circuit.
Repair or replace damaged wiring found in the signal, supply or ground circuit.
Replace the inverter voltage sensor or inverter assembly if testing proves it faulty, as per the model's procedure.
Restore a healthy 12 V supply by charging or replacing the battery and repairing poor earths.
Update the control unit software if an outdated calibration is a known cause for that model.

Can I keep driving?

Medium severity

The car may be driveable if it runs normally, but it can enter limp mode or lose drive without warning, so have it checked soon. Stop driving if the car loses power, shows a red warning or will not stay in Ready mode.

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