Reductant Injection Valve Circuit High Bank 1 Unit 1
The P2049 code indicates that the powertrain control module (PCM) has detected a high voltage condition in the reductant injection valve circuit for Bank 1 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. A high circuit voltage typically points to a short to power, open circuit, or faulty valve or wiring.
01. Most Common Causes
- Faulty reductant injection valve
- Short to power in the valve circuit
- Open or damaged wiring/connectors
- Corroded or loose electrical connections
- Failed PCM (rare)
02. Symptoms You Will Notice
- Illuminated check engine light
- Reduced engine performance or power
- Increased exhaust emissions
- Possible DEF system warning messages
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 reductant injection valve and its wiring for damage, corrosion, or loose connections.
Step 3: Test the valve's resistance with a multimeter; compare to manufacturer specs.
Step 4: Check for voltage at the valve connector with the ignition on; should be battery voltage on one pin.
Step 5: If voltage is present and valve resistance is out of spec, replace the valve.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as it can cause increased emissions and potential damage to the SCR system. The vehicle may enter limp mode to protect the engine.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for parts and labor, depending on the vehicle and shop rates.