Reductant Injection Valve Circuit/Open Bank 1 Unit 1
P2047 indicates the reductant injection valve circuit (also called selective catalytic reduction or SCR valve) on Bank 1 is open or has an electrical circuit fault. This prevents proper injection of urea/diesel exhaust fluid (DEF) into the exhaust stream, reducing emissions control effectiveness and risking catalyst damage if not repaired promptly.
What You Might Notice
- Diminished engine performance or power loss
- Excessive black smoke from exhaust
- Reduced fuel efficiency
- Check engine light illuminated
- Other SCR-related diagnostic codes
Most Common Causes
- 1
Faulty reductant injection valve
The SCR valve solenoid may be stuck open, electrically failed, or mechanically damaged, preventing proper DEF injection control.
- 2
Open or shorted wiring in valve circuit
Corroded, broken, or damaged wiring/connectors between the valve and engine control module interrupt electrical signal transmission.
- 3
Engine control module (ECM) malfunction
The ECM may have failed to properly command or communicate with the reductant injection valve due to internal electronic faults.
- 4
Clogged or failed DEF system components
Low DEF fluid level, contaminated DEF, or blockages upstream of the injection valve can cause the valve circuit to operate abnormally.
How to Diagnose It
- 1
Check Faulty reductant injection valve — The SCR valve solenoid may be stuck open, electrically failed, or mechanically damaged, preventing proper DEF injection control.
- 2
Check Open or shorted wiring in valve circuit — Corroded, broken, or damaged wiring/connectors between the valve and engine control module interrupt electrical signal transmission.
- 3
Check Engine control module (ECM) malfunction — The ECM may have failed to properly command or communicate with the reductant injection valve due to internal electronic faults.
- 4
Check Clogged or failed DEF system components — Low DEF fluid level, contaminated DEF, or blockages upstream of the injection valve can cause the valve circuit to operate abnormally.
How to Fix It
- 1
Replace reductant injection valve
Remove and replace the faulty SCR reductant injection valve solenoid assembly with an OEM or equivalent replacement part. Test valve operation after installation.
- 2
Repair or replace wiring and connectors
Inspect the valve circuit wiring harness for corrosion, breaks, or loose connections. Repair damaged sections or replace the entire harness as needed.
- 3
Check and refill DEF fluid
Verify DEF fluid level and quality in the reductant tank. Top up with OEM diesel exhaust fluid and clear any system blockages if contamination is suspected.
- 4
Diagnose or reprogram engine control module
Use diagnostic equipment to test ECM communication with the reductant valve. If necessary, reprogram or replace the ECM if internal faults are detected.
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