Reductant Injection Valve Circuit Range/Performance Bank 2 Unit 1
The P201A code indicates that the powertrain control module (PCM) has detected a range or performance issue in the reductant injection valve circuit for Bank 2, Unit 1. This valve is part of the Selective Catalytic Reduction (SCR) system, which injects diesel exhaust fluid (DEF) into the exhaust stream to reduce NOx emissions. The PCM monitors the valve's electrical circuit and performance; if the resistance, voltage, or response time is outside expected parameters, this code sets. Common causes include a faulty reductant injection valve, wiring issues, or a malfunctioning DEF pump.
1. Most Common Causes
- Faulty reductant injection valve
- Open or shorted wiring in the valve circuit
- Corroded or loose electrical connectors
- Failed DEF pump or control module
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine performance or limp mode
- Increased NOx emissions
- Possible DEF warning message on dashboard
3. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for related codes.
Step 2: Visually inspect the reductant injection valve and its wiring for damage or corrosion.
Step 3: Test the valve's resistance with a multimeter and compare to manufacturer specs.
Step 4: Check the DEF pump operation and fluid level; perform a system test if available.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as it can lead to reduced performance, increased emissions, and potential damage to the SCR system. Limp mode may activate.
How much does it cost to fix?▼
Diagnosis typically costs $50-$150. Replacing the reductant injection valve can range from $200-$600 including parts and labor, depending on vehicle make and model.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.