Land Rover DTC P0138 – Oxygen Sensor High Voltage *Codes* A D
DTC P0138 meaning on Land Rover
The DTC P0138 code on a Land Rover indicates that the oxygen sensor (O2 sensor) located after the catalytic converter is reading a high voltage signal. This typically means that the O2 sensor is detecting a rich air-fuel mixture in the exhaust system.
Land Rover DTC P0138 symptoms
Common symptoms associated with DTC P0138 on a Land Rover may include:
- Illuminated check engine light
- Possible decrease in fuel efficiency
- Engine running rough or misfiring
Land Rover DTC P0138 causes
The high voltage reading from the oxygen sensor triggering DTC P0138 on a Land Rover can be caused by various factors, such as:
- Faulty oxygen sensor
- Rich air-fuel mixture due to issues with fuel injectors or fuel pressure
- Exhaust leaks near the oxygen sensor
- Wiring or connector issues in the O2 sensor circuit
Land Rover DTC P0138 seriousness
While DTC P0138 may not cause immediate drivability issues, it can lead to decreased fuel efficiency and potential long-term damage to the catalytic converter if left unresolved. It is recommended to address this issue promptly.
How to diagnose DTC P0138 on Land Rover
To diagnose DTC P0138 on a Land Rover, a mechanic would typically:
- Use a scan tool to retrieve the specific fault code and freeze frame data
- Inspect the oxygen sensor and its wiring for any visible damage or corrosion
- Check for exhaust leaks near the oxygen sensor
- Test the oxygen sensor’s voltage output using a multimeter
How to fix DTC P0138 on Land Rover
To address DTC P0138 on a Land Rover, the following steps may be taken:
- Replace the faulty oxygen sensor
- Repair any wiring or connector issues in the O2 sensor circuit
- Address any underlying issues causing a rich air-fuel mixture, such as fuel injector problems
- Clear the fault code and reset the check engine light
How to erase DTC P0138 on Land Rover
To erase the DTC P0138 code on a Land Rover, a scan tool can be used to clear the code and reset the check engine light. It is important to ensure that the underlying issue causing the fault code has been addressed before clearing the code.
Recommended tools for Land Rover 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.