What it means
The control module monitors the signal from ambient air temperature sensor B. It sets this code when the signal falls below the expected range.
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 its signal and sets P00DB when that signal is below the expected electrical range; a signal low condition can result from a short to ground, a failed sensor, or damaged wiring.
Common causes
Most likely first.
- Signal wire shorted to ground
- Failed sensor B
- Damaged wiring or poor connector contact
Symptoms
- Check-engine light on
- Outside-temperature display may be inaccurate
- Climate control may respond incorrectly
How to diagnose it
- Check freeze-frame data and live readings for sensor B; a reading pinned at an extreme or inconsistent with ambient conditions helps confirm the low-signal fault.
- Inspect sensor B's connector and wiring for chafing, crushed insulation, corrosion, or a signal wire touching ground.
- Check for poor connector contact or a short to ground in the sensor B signal circuit using the manufacturer's wiring information.
- Test sensor B and its circuit as specified by the manufacturer to determine whether the sensor itself is pulling the signal low.
- Repair the wiring or replace sensor B as indicated, then confirm live data responds plausibly.
Common fixes
- Repair a signal wire shorted to ground or chafed through to ground.
- Restore poor contact at the sensor B connector.
- Replace ambient air temperature sensor B if it fails the manufacturer's test.
Can I keep driving?
This fault usually causes an inaccurate outside-temperature display or climate-control behavior and does not normally prevent driving. If the vehicle also shows engine-performance symptoms, diagnose those separately rather than assuming this sensor code explains them.
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.