Reductant Injection Valve Stuck Closed Bank 2 Unit 1
The P208F code indicates that the reductant injection valve for Bank 2 Unit 1 is stuck closed. 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. When stuck closed, DEF cannot be injected, leading to increased emissions and potential performance issues. The valve may be mechanically seized, electrically faulty, or the DEF quality may be poor.
01. Most Common Causes
- Faulty reductant injection valve
- Wiring or connector issues in the valve circuit
- Contaminated or poor-quality DEF fluid
- Frozen DEF fluid in cold weather
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine performance or power
- Increased exhaust emissions
- Possible DEF warning light on dashboard
03. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for related codes.
Step 2: Inspect the reductant injection valve and its wiring for damage, corrosion, or loose connections.
Step 3: Test the valve's resistance and operation using a multimeter and scan tool commands.
Step 4: Check DEF fluid level and quality; replace if contaminated or frozen.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
Driving with this code is not recommended as it can lead to increased emissions and potential damage to the SCR system. In some vehicles, it may trigger a derate mode, reducing engine power.
How much does it cost to fix?▼
The cost to fix a P208F code typically ranges from $50 to $150 for diagnosis and replacement of the valve, though labor and parts may vary depending on the vehicle.