OBD-II reference

All 9.533 generic OBD-II codes, explained in detail.

Causes, inspection steps and sources — a comprehensive DIY archive. Created and maintained with love for the detail. Good luck and have fun!

Powertrain generic / SAE

P00D9

Ambient Air Temperature Sensor Circuit B

Generic electrical fault on ambient air temperature sensor B (second sensor for redundancy or second measurement location).

SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number– / D9

Possible causes

  • Sensor failed high

Inspection / repair

  • Difficulty: easy
  • DIY: possible
  • Estimated cost: 30–200 €
  • Estimated time: 0.3–1 h
  • Component: ambient air temp sensor b
  • Component: sensor wiring
  • MIL / check engine light

Sources

References

sae:J2012

How to read OBD-II codes

The first letter names the vehicle system, the second digit distinguishes generic from manufacturer-specific, the remaining digits group fault area and number.

PPowertrain: engine, transmission, emissions
BBody: chassis trim, comfort, interior
CChassis: suspension, brakes, steering
UNetwork: CAN, control modules, communication