Reductant Injection Valve Circuit Low Bank 2 Unit 2
P2057 indicates the reductant injection valve circuit on Bank 2 Unit 2 is detecting a low voltage condition. This valve controls the flow of diesel exhaust fluid (DEF) into the selective catalytic reduction (SCR) system to reduce nitrogen oxide emissions. Without prompt repair, catalyst damage and increased emissions can result.
What You Might Notice
- Diminished engine performance
- Excessive black smoke from exhaust
- Reduced fuel efficiency
- Check Engine light illuminated
- Other SCR or emissions-related codes present
Most Common Causes
- 1
Faulty reductant injection valve
The solenoid valve on Bank 2 Unit 2 may be failing or stuck closed, preventing proper current flow through the circuit.
- 2
Open or corroded wiring connections
Broken wires, poor connections, or corrosion in the valve circuit harness can cause low voltage conditions.
- 3
Defective SCR control module or PCM
The engine control module may have a programming error or internal fault preventing proper voltage delivery to the injector valve.
- 4
Low or depleted reductant supply
Insufficient DEF fluid level or contaminated reductant can trigger the valve circuit to set this code.
How to Diagnose It
- 1
Check Faulty reductant injection valve — The solenoid valve on Bank 2 Unit 2 may be failing or stuck closed, preventing proper current flow through the circuit.
- 2
Check Open or corroded wiring connections — Broken wires, poor connections, or corrosion in the valve circuit harness can cause low voltage conditions.
- 3
Check Defective SCR control module or PCM — The engine control module may have a programming error or internal fault preventing proper voltage delivery to the injector valve.
- 4
Check Low or depleted reductant supply — Insufficient DEF fluid level or contaminated reductant can trigger the valve circuit to set this code.
How to Fix It
- 1
Inspect and repair wiring harness
Check the reductant injection valve circuit connector and wiring for corrosion, breaks, or loose connections. Clean or replace corroded terminals and repair damaged wiring.
- 2
Replace reductant injection valve
Remove and replace the solenoid valve on Bank 2 Unit 2 if inspection shows it is stuck, burned out, or internally damaged.
- 3
Verify DEF fluid level and quality
Check that the reductant tank contains adequate DEF fluid and that it has not become contaminated. Top off or replace fluid as needed.
- 4
Test and reprogram SCR control module
Use a diagnostic scanner to test module output voltage and reprogram or replace the SCR controller if internal faults are detected.
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