Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means there's a problem with a part of the car that helps clean the exhaust. It's like a valve that isn't working right, and it needs to be checked out.
The P20A3 code indicates that the reductant purge control valve circuit is experiencing a higher than expected voltage, which suggests an electrical issue.
The reductant purge control valve is part of the vehicle's Selective Catalytic Reduction (SCR) system, which reduces emissions by injecting a urea-based fluid into the exhaust. The 'Circuit High' status means the Engine Control Module (ECM) has detected a higher than normal voltage in the valve's circuit, which could be due to an electrical fault or a malfunctioning valve.
• Check Engine Light is on
• Possible reduction in engine performance
• Increased emissions
• Faulty reductant purge control valve
• Wiring issues such as shorts or open circuits
• Faulty ECM or control module
Reductant: A fluid used in the SCR system to reduce emissions.
SCR: Selective Catalytic Reduction, a system used to reduce vehicle emissions.
• Use an OBD-II scanner to confirm the code
• Inspect the wiring and connectors for damage or corrosion
• Test the reductant purge control valve for proper operation
• Replace the reductant purge control valve if faulty
• Repair or replace damaged wiring or connectors
• Update or reprogram the ECM if necessary
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $400
Moderate
• Ford F-Series
• Chevrolet Silverado
• Ram 1500
• Regularly inspect and maintain the exhaust system
• Ensure proper fluid levels in the SCR system
• Schedule routine vehicle diagnostics
Sensor Issue
• Do not ignore the Check Engine Light
• Consult a professional mechanic for diagnosis
• Consider regular maintenance to prevent future issues
Check with your vehicle manufacturer for warranty coverage on emissions-related components.
This code has been associated with vehicles using SCR systems to reduce emissions, particularly in diesel engines.
Moderate – Addressing this issue is important to maintain emissions compliance and engine performance.
Driving with a malfunctioning emissions system may not meet legal emissions standards and could result in fines.
• Engine running
• Vehicle at operating temperature
The reductant purge control valve is typically located near the SCR system, which is part of the vehicle's exhaust system.
Q: Can I drive my car with a P20A3 code?
A: While the car may still be drivable, it's best to address the issue to avoid increased emissions and potential engine performance problems.
Q: What happens if I ignore the P20A3 code?
A: Ignoring the code can lead to increased emissions, potential engine performance issues, and may result in failing an emissions test.
High-End · Full-system diagnostics
A full-system bidirectional platform aimed at advanced DIY users and professional diagnostic workflows.
Network faults often require full-system access instead of a generic code reader alone.
View on Amazon
Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
View on Amazon
Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
View on AmazonThese are optional diagnostic tools, not guaranteed fixes. As an Amazon Associate I earn from qualifying purchases.