Audi P1103: O2 Sensor Circuit (Bank 1-Sensor 1) Output Too Low

What Does The Audi P1103 Code Mean?

Engine started, battery voltage must be at least 11.5v, all electrical components must be off, the ground between the engine and the chassis must be well connected, the exhaust system must be properly sealed between the catalytic converter and the cylinder head, and the oxygen sensor heater for oxygen sensor before the catalytic converter must be properly functioning. The ECM detected a voltage on the O2 sensor circuit that was outside the parameters to function properly.

Note: For resistance testing of sensor heating, oxygen sensor should be cooled to ambient temperature. High temperatures at oxygen sensor may lead to inaccurate measurements.

What Are The Potential Causes Of The Audi P1103 Code?

Below are some potential causes of this DTC:

• Oxygen sensor (before catalytic converter) is faulty
• Oxygen sensor (behind catalytic converter) is faulty
• Oxygen sensor heater (before catalytic converter) is faulty
• Oxygen sensor heater (behind catalytic converter) is faulty
• Circuit wiring has a short to power or ground
• Engine Component Power Supply Relay is faulty
• E-box fuses for oxygen sensor are faulty
• Leaks present in the exhaust manifold or exhaust pipes
• HO2S signal wire and ground wire crossed in connector
• HO2S element is fuel contaminated or has failed
• ECM has failed

Recommended Parts

Below are some recommended auto parts to help you address the trouble code affecting your vehicle and get it running smoothly again:

>>> Twippo 372Pcs Waterproof Wire Connectors Kit
>>> A-Premium O2 Oxygen Sensor
>>> Audi Engine Control Module
>>> VF7-11F11-S01 Automotive Relay 12V, 70 AMP Plug-in, 4-1393306-6
>>> FEL-PRO MS 96116 Exhaust Manifold Gasket Set

Note: During the purchasing process, please check carefully whether the part you want to buy fits your car!

Reference Sources

Audi, 2013, 2014 A8/A8L/S8 Quick Reference Specification Book, page 358.