Reductant Injection Valve Circuit/Open Bank 2 Unit 2
The reductant injection valve circuit on Bank 2, Unit 2 is open or has an electrical fault, preventing proper operation of the selective catalytic reduction (SCR) system. This code indicates the engine cannot properly inject reductant (DEF) to reduce nitrogen oxide emissions, which can lead to catalyst damage if not corrected promptly.
What You Might Notice
- Diminished engine performance
- Excessive black smoke from exhaust
- Reduced fuel efficiency
- Check engine light illuminated
- Other SCR-related fault codes present
Most Common Causes
- 1
Faulty reductant injection valve
The solenoid valve that controls DEF injection is stuck open, failed, or electrically disconnected. This prevents proper reductant delivery to the SCR catalyst.
- 2
Open or broken wiring to valve
Wiring harness to the reductant valve is corroded, broken, or disconnected, cutting power to the solenoid and preventing it from operating.
- 3
Bad valve control module or relay
The SCR module or its relay is malfunctioning, preventing proper electrical signal delivery to the injection valve circuit.
- 4
Blocked or frozen DEF line
The reductant delivery line to Bank 2 Unit 2 is clogged or frozen, causing system pressure that triggers an open circuit fault condition.
How to Diagnose It
- 1
Check Faulty reductant injection valve — The solenoid valve that controls DEF injection is stuck open, failed, or electrically disconnected. This prevents proper reductant delivery to the SCR catalyst.
- 2
Check Open or broken wiring to valve — Wiring harness to the reductant valve is corroded, broken, or disconnected, cutting power to the solenoid and preventing it from operating.
- 3
Check Bad valve control module or relay — The SCR module or its relay is malfunctioning, preventing proper electrical signal delivery to the injection valve circuit.
- 4
Check Blocked or frozen DEF line — The reductant delivery line to Bank 2 Unit 2 is clogged or frozen, causing system pressure that triggers an open circuit fault condition.
How to Fix It
- 1
Inspect and repair valve wiring
Check the entire wiring harness from the SCR module to the reductant injection valve on Bank 2 Unit 2 for corrosion, breaks, or loose connectors. Repair or replace damaged wiring and reconnect any loose terminals.
- 2
Replace reductant injection valve
Remove and replace the faulty solenoid valve on Bank 2 Unit 2 with a new OEM reductant injection valve. This is the most common fix for this code.
- 3
Test and replace SCR control module
Use a diagnostic scanner to test the SCR module's ability to command the valve. If the module cannot produce proper signal voltage, replace the SCR control module.
- 4
Inspect DEF system for blockages
Check the reductant line to Bank 2 Unit 2 for ice crystals, debris, or clogs. Flush the DEF system or replace the supply line as needed. Ensure proper DEF quality and storage conditions.
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