Reductant Injection Valve Circuit High Bank 2 Unit 1
The reductant injection valve circuit on Bank 2 is detecting a high voltage condition, indicating a potential electrical fault in the SCR (Selective Catalytic Reduction) system. This prevents proper injection of diesel exhaust fluid (DEF), which reduces emissions control effectiveness and can lead to catalyst damage if not addressed 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 valve solenoid on Bank 2 may be stuck, shorted internally, or failing electrically, causing the high voltage signal to the PCM.
- 2
Wiring issues or connector problems
Open circuits, corroded connectors, or damaged wiring in the reductant valve circuit can cause intermittent or continuous high voltage readings.
- 3
PCM or module malfunction
The powertrain control module or SCR control module may have failed or developed a fault in the valve control circuit driver.
- 4
Power supply voltage issues
Excessive voltage from the battery or charging system can cause the valve circuit to register high voltage at the sensor.
How to Diagnose It
- 1
Check Faulty reductant injection valve — The valve solenoid on Bank 2 may be stuck, shorted internally, or failing electrically, causing the high voltage signal to the PCM.
- 2
Check Wiring issues or connector problems — Open circuits, corroded connectors, or damaged wiring in the reductant valve circuit can cause intermittent or continuous high voltage readings.
- 3
Check PCM or module malfunction — The powertrain control module or SCR control module may have failed or developed a fault in the valve control circuit driver.
- 4
Check Power supply voltage issues — Excessive voltage from the battery or charging system can cause the valve circuit to register high voltage at the sensor.
How to Fix It
- 1
Inspect and test reductant valve
Visually inspect the Bank 2 reductant injection valve for damage or debris, then test with a multimeter for proper resistance and continuity before replacing if necessary.
- 2
Check and repair wiring and connectors
Inspect the entire wiring harness and connectors for the reductant valve circuit for corrosion, damage, or loose connections; repair or replace as needed.
- 3
Clear codes and perform system test
After repairs, clear the diagnostic trouble code using a scanner and perform a test drive to verify the valve circuit voltage returns to normal range.
- 4
Replace PCM or SCR control module if needed
If valve and wiring test normal, reprogram or replace the powertrain control module or dedicated SCR module to resolve internal electrical faults.
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