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2007 AUDI A8

4.2L V8AWDAUTOMATICgas
2 active safety recalls on this vehicle — view recalls
Repairs0Labor505Torque2471Fluid9DTC839Battery0Maintenance0Recalls2
P0030low severityPowertrain

HO2S Heater Control Circuit Bank 1 Sensor 1

on 2007 Audi A8 4.2L V8 · AWD

What this code means

The PCM detected a malfunction in the heater circuit of the upstream heated oxygen sensor (Bank 1, Sensor 1).

Symptoms

  • Check Engine Light
  • Poor fuel economy
  • Longer warmup emissions
  • Failed emissions test

Common causes

  • Faulty O2 sensor heater
  • Blown fuse
  • Wiring issue
  • PCM heater driver failure

Diagnostic steps

  1. Check O2 sensor heater fuse
  2. Test heater circuit resistance (should be 2-30 ohms)
  3. Inspect wiring to sensor
  4. Check PCM heater control output

Repair notes

Replace O2 sensor if heater resistance is out of spec. Check fuse and wiring first.

Other Powertrain codes on this vehicle

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