P203A Fault Code

Reductant Level Sensor Circuit

• What does that mean?
• Symptoms
• Causes
• Solutions

The P203A fault code signifies an issue with the Reductant Level Sensor Circuit. This sensor plays a critical role in monitoring the level of diesel exhaust fluid (DEF) in vehicles equipped with selective catalytic reduction (SCR) systems. When the sensor experiences a fault, it can lead to improper readings, affecting emission control and engine performance.

What are the symptoms of the P203A code?

Common symptoms associated with a P203A fault code include:

• Illumination of the check engine light
• Incorrect DEF level readings displayed on the dashboard
• Reduced engine performance or power
• Increased exhaust emissions
• Possible engine derate, limiting vehicle speed and power.

What causes the P203A code?

Several factors can trigger a P203A code, including:

• A malfunctioning reductant level sensor
• Damaged wiring or connectors in the sensor circuit
• Low levels of diesel exhaust fluid (DEF)
• Faulty vehicle computer programming or software
• Contaminated DEF or sensor corrosion due to environmental factors.

How to fix P203A?

To resolve a P203A fault code, the following steps may be taken:

• Inspect and test the reductant level sensor for proper operation
• Check wiring and connectors for damage or corrosion
• Ensure the DEF tank is adequately filled with high-quality fluid
• Clear any stored fault codes and perform a test drive to verify the issue has been resolved
• If necessary, reprogram the vehicle's computer to ensure compatibility with the sensor.