P0A21
Motor Torque Sensor Circuit Intermittent
- Severity
- Medium
- Driving
- Drive only to a garage
The drive motor torque sensor signal is dropping out intermittently. The vehicle drives normally and then restricts itself, often recovering after a restart. As with all intermittent circuit faults, connections are far more likely than the sensor.
Possible causes
- CommonLoose, corroded or backed-out connector pin
- CommonChafed or fatigued wiring
- CommonLow 12 volt battery voltage
- PossibleSensor dropping out when hot
- PossibleWater ingress into the connector
What you might notice
- Occasional reduced power that clears after a restart
- Hybrid system warning message coming and going
- Performance varying between journeys
- Fault linked to heat or to wet weather
What to check, in order
- Check the 12 volt battery and have it load tested. On hybrids a marginal 12 volt battery produces intermittent faults across the whole vehicle.
- Note when it happens - hot, over bumps, or in the wet.
- Inspect the connector for a backed-out pin and for corrosion.
- Record the freeze frame data if the tool supports it.
- Do not disturb anything orange.
Read this code from your own car
Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.
Where this code sits
P00xxP01xxP02xxP03xxP04xxP05xxP06xxP07xxP08xxP09xxP0AxxP0BxxP0CxxP0DxxP0ExxP0FxxP10xxP11xxP12xxP13xxP14xxP15xxP16xxP17xxP18xxP19xxP1AxxP1BxxP1CxxP1DxxP1ExxP1FxxP20xxP21xxP22xxP23xxP24xxP25xxP26xxP27xxP28xxP29xxP2AxxP2BxxP2CxxP2DxxP2ExxP2FxxP30xxP31xxP32xxP33xxP34xxP35xxP36xxP37xxP38xxP39xxP3AxxP3BxxP3CxxP3DxxP3ExxP3Fxx