What it means
The control module monitors the signal from ambient air temperature sensor B for stable readings. It sets this code when the signal repeatedly drops out or changes erratically.
At a glance
- Usually lights the check-engine light
How it works
Ambient air temperature sensor B measures outside air at its particular sensing location, which may be separate from sensor A. The control module monitors the stability of sensor B's signal and sets P00DD when it drops out or changes erratically, often because of a loose connection, intermittent wiring fault, or failing sensor.
Common causes
Most likely first.
- Loose or damaged connector
- Intermittent wiring fault
- Intermittent sensor fault
Symptoms
- Check-engine light on
- Outside-temperature display may fluctuate or be inaccurate
- Climate control may respond inconsistently
How to diagnose it
- Review freeze-frame data and live sensor B readings for sudden jumps or dropouts, and note the conditions when they occur.
- Inspect sensor B's connector and harness for looseness, corrosion, chafing, or damage where vibration could interrupt contact.
- Watch the live reading while gently checking the accessible harness and connector for changes that reproduce the fault.
- Test the sensor B circuit for intermittent opens or shorts using the manufacturer's wiring information.
- If the circuit remains stable, test sensor B against the manufacturer's specification and replace it if its output is erratic.
Common fixes
- Secure a loose sensor B connector and clean poor contacts.
- Repair wiring that intermittently opens or shorts.
- Replace ambient air temperature sensor B if its signal remains erratic with sound wiring.
Can I keep driving?
The fault usually affects the outside-temperature display or climate control rather than engine operation, so driving is generally possible. If climate control changes unexpectedly, bear that in mind while driving and arrange diagnosis.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.