Reductant Purge Control Valve Circuit/Open
The P20A0 code indicates a problem in the electrical circuit of the reductant purge control valve, which is part of the Selective Catalytic Reduction (SCR) system used to reduce NOx emissions in diesel vehicles. The valve controls the flow of diesel exhaust fluid (DEF) into the exhaust stream. An open circuit means there is a break in the wiring or a faulty valve, preventing proper operation and potentially causing increased emissions.
01. Most Common Causes
- Faulty reductant purge control valve
- Open or shorted wiring in the valve circuit
- Corroded or loose electrical connectors
- Blown fuse or relay issue
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine performance or power
- Increased diesel exhaust fluid consumption
- Failed emissions test
03. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for related codes.
Step 2: Visually inspect the valve and wiring for damage, corrosion, or loose connections.
Step 3: Test the valve resistance with a multimeter; compare to manufacturer specs.
Step 4: Check for voltage at the valve connector with the ignition on; if no voltage, inspect fuses and relays.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is generally safe to drive short distances, but continued driving may cause increased emissions and potential damage to the SCR system. It is recommended to diagnose and repair promptly.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for parts and labor, depending on whether the valve or wiring needs replacement.