Common Symptoms
- Check engine light illuminated
- DEF system warning light or message displayed
- Poor DEF fluid consumption or excessive DEF usage
- Reduced engine power or derate condition
- Difficulty starting in cold weather
- Increased NOx emissions
Most Likely Root Causes
- Faulty DEF injector on bank 2
- Damaged or corroded wiring harness to DEF injector
- Failed DEF injector driver circuit in ECM
- Poor electrical connections at DEF injector connector
- Contaminated or crystallized DEF causing injector blockage
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Component Location
The DEF injector for bank 2 is typically located in the exhaust system upstream of the SCR catalyst on the second bank of the engine.
Manufacturer Notes
Some diesel engines with dual SCR systems require specific DEF injector relearn procedures after replacement or circuit repairs.
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