HO2S Heater Resistance Bank 1 Sensor 2
1997-2003 Audi A8 4.2L V8
Description
The ECU detected that the heater resistance in the downstream oxygen sensor on Bank 1 is outside the expected range. The downstream sensor monitors catalytic converter efficiency and requires proper heater function.
Symptoms
- Check Engine Light
- Failed emissions test
- Poor catalyst monitoring
- Slightly reduced fuel economy
Common Causes
- Faulty downstream O2 sensor heater
- High resistance in heater wiring
- Corroded connector at sensor
- Heater relay failure
Diagnostic Steps
- Test downstream O2 sensor heater resistance
- Inspect connector for corrosion
- Check heater circuit wiring
- Test heater relay operation
Repair Notes
Replace the downstream O2 sensor on Bank 1.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P1105 on Other Vehicles
Common Questions
What does code P1105 mean on a 1997-2003 Audi A8?
P1105 stands for "HO2S Heater Resistance Bank 1 Sensor 2". The ECU detected that the heater resistance in the downstream oxygen sensor on Bank 1 is outside the expected range. The downstream sensor monitors catalytic converter efficiency and requires proper heater function.
What are the symptoms of P1105 on a Audi A8?
Common symptoms of P1105 include: Check Engine Light, Failed emissions test, Poor catalyst monitoring, Slightly reduced fuel economy.
What causes P1105 on a 1997-2003 Audi A8?
Common causes of P1105 include: Faulty downstream O2 sensor heater, High resistance in heater wiring, Corroded connector at sensor, Heater relay failure.