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2009 AUDI TT
3.2L V6•AWD•DCT•gas•BUB
2 active safety recalls on this vehicle — view recalls
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Repairs0Labor496Torque2184Fluid10DTC1087Battery1Maintenance0Recalls2
P1102moderate severityPowertrain

HO2S Heater Resistance Bank 1 Sensor 1

on 2009 Audi TT 3.2L V6 · AWD

What this code means

The ECU detected that the heater resistance in the upstream oxygen sensor on Bank 1 is outside the specified range. The heater brings the O2 sensor up to operating temperature quickly for accurate fuel trim control.

Symptoms

  • Check Engine Light
  • Poor cold-start fuel economy
  • Extended warmup emissions
  • Failed emissions test

Common causes

  • Faulty O2 sensor heater element
  • High-resistance connection in heater circuit
  • Corroded O2 sensor connector
  • Blown heater circuit fuse

Diagnostic steps

  1. Test O2 sensor heater resistance (should be 2-30 ohms)
  2. Check heater circuit fuse
  3. Inspect wiring and connector for corrosion
  4. Measure voltage at heater circuit

Repair notes

Replace the upstream O2 sensor on Bank 1 if heater resistance is out of specification.

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