P2238 – Audi DTC

Audi DTC P2238 – Exhaust leak, Oxygen sensor failure, Powertrain Control Module (PCM) failure, Wiring issue

DTC P2238 meaning on Audi

DTC P2238 refers to a specific diagnostic trouble code that indicates a problem with the oxygen sensor circuit in Audi vehicles. This code is triggered when the Powertrain Control Module (PCM) detects an abnormal voltage signal from the oxygen sensor, which is responsible for monitoring the level of oxygen in the exhaust gases. A reading outside the expected range can suggest issues such as an exhaust leak, sensor failure, or wiring problems.

Audi DTC P2238 symptoms

Common symptoms associated with DTC P2238 may include:

• Check Engine Light illuminated
• Decreased fuel efficiency
• Rough engine idle
• Increased emissions
• Loss of power during acceleration

Audi DTC P2238 causes

Several factors can lead to the triggering of DTC P2238, including:

• Exhaust leak near the oxygen sensor
• Faulty oxygen sensor
• Powertrain Control Module (PCM) failure
• Wiring issues, such as damaged or corroded connectors

Audi DTC P2238 seriousness

DTC P2238 is considered a serious issue as it can affect engine performance and fuel efficiency. If left unaddressed, it may lead to further engine damage or increased emissions, which can result in failing emissions tests. It is advisable to diagnose and repair the issue promptly to maintain optimal vehicle performance.

How to diagnose DTC P2238 on Audi

To diagnose DTC P2238, follow these steps:

1. Use an OBD-II scanner to confirm the presence of DTC P2238.
2. Inspect the oxygen sensor and its wiring for any visible damage or corrosion.
3. Check for exhaust leaks near the oxygen sensor.
4. Test the voltage output of the oxygen sensor using a multimeter.
5. Examine the Powertrain Control Module (PCM) for any faults.

How to fix DTC P2238 on Audi step-by-step instructions

To fix DTC P2238, follow these steps:

1. Repair or replace any damaged wiring or connectors related to the oxygen sensor.
2. Fix any exhaust leaks found during the diagnosis.
3. If the oxygen sensor is faulty, replace it with a new one.
4. Recheck the PCM for any updates or faults and reprogram if necessary.
5. Clear the DTC using an OBD-II scanner and test drive the vehicle to ensure the issue is resolved.

How to erase DTC P2238 on Audi

To erase DTC P2238, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn on the ignition without starting the engine.
3. Navigate to the ‘Erase Codes’ or ‘Clear DTCs’ option on the scanner.
4. Confirm the action to clear the trouble codes.
5. Disconnect the scanner and start the engine to verify that the code does not reappear.

Recommended tools for Audi diagnostics

Explore our expert picks: The Best OBD2 Scanners for 2025

Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter

Some of the links on this page may be affiliate links, which means we may earn a small commission if you make a purchase. This helps us keep our DTC database up to date and provide valuable content for free. We only recommend products that we have tested and believe to be the best in their class.