Open circuit in the sensor signal or ground wire; Faulty ambient air temperature sensor (internal open circuit); Corroded, loose or damaged sensor connector or terminals; Signal wire shorted to a voltage supply; Damaged wiring from front-end repairs, impact or rubbing on bodywork; Fault in the control unit that reads the sensor, or a software issue where a known calibration fault exists.

P00DC

Ambient Air Temperature Sensor Circuit B High.

Generic
Powertrain
Generic code
Low severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
0: AreaFuel and air metering, auxiliary emission controls
DC: FaultThe specific fault in that area

What it means

P00DC means the control unit has seen the signal from the second (circuit B) ambient air temperature sensor sitting above the expected range. On a typical thermistor sensor, a high voltage reads as an extremely cold temperature, and it usually points to an open circuit or a short to a voltage supply. Which sensor counts as 'B' depends on the vehicle, so check the model-specific data.

Symptoms

Engine warning light on
Outside temperature display on the dash shows dashes or an implausible, very low reading
Automatic climate control behaving oddly, such as poor temperature regulation or blower speed
Slightly rougher cold starts or changes in idle on some models
Intermittent fault that comes and goes with vibration or damp weather

Possible causes

Open circuit in the sensor signal or ground wirelikely
Faulty ambient air temperature sensor (internal open circuit)likely
Corroded, loose or damaged sensor connector or terminalslikely
Signal wire shorted to a voltage supplypossible
Damaged wiring from front-end repairs, impact or rubbing on bodyworkpossible
Fault in the control unit that reads the sensor, or a software issue where a known calibration fault existsrare

How to diagnose

Read the freeze frame data and any other stored codes, noting whether the fault is current or historic
Compare the live ambient temperature reading with the intake air and coolant temperatures on a cold engine; they should be similar
Check the sensor location for the model, then inspect the sensor, connector and nearby wiring for damage, water ingress or corrosion
Disconnect the sensor and check the terminals for corrosion or bent pins, then reconnect firmly and see if the reading changes
With the sensor unplugged, measure its resistance and compare it against the manufacturer's temperature-resistance values
Check the reference voltage and ground at the connector with the ignition on, using the wiring diagram for that model
Test the signal wire for continuity to the control unit and for a short to supply voltage
Clear the code and road test, rechecking the live reading to confirm the repair

How to fix

Repair or replace damaged wiring, correcting any open circuit or short to supply
Clean or replace the corroded connector or terminals and secure them properly
Replace the ambient air temperature sensor if it is out of specification
Re-route and secure the harness away from sharp edges or heat sources
Update the control unit software only if the manufacturer lists a calibration fault for this code on that model

Can I keep driving?

Low severity

The car can normally be driven while you book it in, as this code rarely affects safety. Get it checked soon, because the fault may affect climate control and could hide other problems.

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