P2055: Reductant Injection Valve Circuit High Bank 1 Unit 2
The P2055 code indicates that the powertrain control module (PCM) has detected a high voltage condition in the reductant injection valve circuit for Bank 1, Unit 2. 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 signal typically means there is a short to voltage, a faulty valve, or a wiring issue. This can lead to improper DEF injection, causing increased emissions and potential damage to the SCR system.
1. Most Common Causes
- Short circuit in the injector wiring to battery voltage (B+)
- DEF injector internally shorted
- Injector connector or pins corroded, damaged, or moisture-contaminated
- Faulty DEF injector control module (if applicable)
- Internal ECM failure in the injector control circuit
- Low resistance in the injector winding due to thermal damage
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine performance
- Increased exhaust emissions
- Possible DEF warning light
- Failed emissions test
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, 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; if voltage is present when it shouldn't be, trace the short.
Step 5: If wiring and valve are okay, test the PCM output circuit; replace PCM if necessary.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances with this code, as it can cause increased emissions and potential damage to the SCR system. However, short trips may be possible if the vehicle is not in limp mode.
How much does it cost to fix?▼
The cost typically ranges from $150 to $400, depending on whether the valve needs replacement or just wiring repair. Labor costs vary by shop.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.