P00DA
Ambient Air Temperature Sensor Circuit B Range/Performance.
- 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
- DA
- FaultThe specific fault in that area
What it means
P00DA is the generic code for an ambient air temperature sensor circuit B range or performance fault. The control unit has seen a reading from that sensor which is implausible, for example it does not match other temperature sensors after a cold soak, is stuck, or changes at an unrealistic rate. The signal is still within the electrical limits, so this points to a sensor or circuit that is reading wrongly rather than one that is open or shorted. What circuit B refers to, and where the sensor is fitted, depends on the model and engine.
Symptoms
- Engine management warning light on
- Ambient temperature on the dashboard display is wrong, stuck or missing
- Climate control or automatic air conditioning behaving oddly
- Slightly rough cold start or altered idle on some models
- Frost or ice warning showing at the wrong time
Possible causes
- Faulty or drifting ambient air temperature sensorlikely
- Corroded, loose or contaminated sensor connector terminalslikely
- Damaged, chafed or high-resistance wiring between the sensor and control unitpossible
- Sensor physically damaged or displaced, or exposed to engine or exhaust heat or road debrispossible
- Poor reference voltage or ground supply to the sensor circuitpossible
- Fault in the control unit or in the network data carrying the temperature valuerare
How to diagnose
- Read all stored and pending codes and the freeze frame data, noting temperature and engine conditions when the fault set, and look for other temperature sensor codes.
- Compare live ambient temperature with the intake air and coolant temperatures after the car has sat for several hours, and with the known outside temperature.
- Inspect the sensor, its mounting position and the surrounding area for damage, dirt, water ingress or heat damage.
- Check the connector for corrosion, bent or pushed-back pins and poor terminal tension, and inspect the wiring for chafing or previous repairs.
- Wiggle test the harness and connector while watching live data to see if the reading jumps.
- Measure the sensor resistance and compare it with the manufacturer's temperature to resistance table for that model.
- Check the reference voltage, signal and ground at the sensor connector against the wiring diagram, including voltage drop on the ground.
- If the sensor and wiring test good, check for software updates or network faults affecting the temperature value, following manufacturer procedures.
How to fix
- Replace the ambient air temperature sensor if its resistance or live reading is out of specification.
- Clean or repair the connector and terminals, or replace the connector if the pins are damaged or corroded.
- Repair or replace damaged wiring, then secure it away from heat and sharp edges.
- Refit, reposition or replace a damaged sensor mounting or shield so the sensor reads true air temperature.
- Restore faulty power or ground supplies found during testing.
- Where a known fault in the control unit software exists for the model, update the calibration to the current manufacturer release.
Can I keep driving?
The car can normally be driven as usual, as this fault mainly affects temperature readings and some minor corrections. Book it in soon so a persistent fault does not hide other problems or affect climate control.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.