Reductant Injection Valve Circuit/Open Bank 1 Unit 2
The reductant injection valve circuit on Bank 1 is open or has excessive resistance, preventing proper selective catalytic reduction (SCR) operation. This code indicates an electrical fault in the valve circuit that controls urea/reductant injection into the exhaust stream for emissions control.
What You Might Notice
- Diminished engine performance
- Excessive black smoke from exhaust
- Reduced fuel efficiency
- Illuminated check engine light
- Other SCR-related diagnostic codes present
Most Common Causes
- 1
Faulty reductant injection valve
The solenoid valve controlling reductant flow is defective, stuck, or electrically failed, interrupting signal transmission to the engine control module.
- 2
Open or broken wiring in valve circuit
Damaged, corroded, or disconnected wiring harness between the valve and ECM prevents proper electrical signal communication.
- 3
Faulty valve connector or contact corrosion
Poor electrical connections at the valve connector due to corrosion, water intrusion, or improper seating cause circuit resistance or open conditions.
- 4
Engine control module (ECM) malfunction
Defective ECM circuitry or module programming failure prevents proper valve driver signal generation.
How to Diagnose It
- 1
Check Faulty reductant injection valve — The solenoid valve controlling reductant flow is defective, stuck, or electrically failed, interrupting signal transmission to the engine control module.
- 2
Check Open or broken wiring in valve circuit — Damaged, corroded, or disconnected wiring harness between the valve and ECM prevents proper electrical signal communication.
- 3
Check Faulty valve connector or contact corrosion — Poor electrical connections at the valve connector due to corrosion, water intrusion, or improper seating cause circuit resistance or open conditions.
- 4
Check Engine control module (ECM) malfunction — Defective ECM circuitry or module programming failure prevents proper valve driver signal generation.
How to Fix It
- 1
Test and replace reductant injection valve
Use a multimeter to test valve resistance and solenoid function; if faulty, replace the entire valve assembly with OEM equivalent.
- 2
Inspect and repair wiring harness
Visually inspect valve circuit wiring for breaks, corrosion, or damage; repair or replace damaged sections and ensure secure connections throughout the circuit.
- 3
Clean or replace valve connector
Disconnect the valve connector and clean corrosion from pins using electrical contact cleaner; if contacts are damaged or heavily corroded, replace the connector.
- 4
Reprogram or replace ECM
After other causes are ruled out, perform ECM reprogramming using manufacturer software or replace the module if internal driver circuit is faulty.
Need a deeper diagnosis?
Search for related repair guides or browse by system.