Reductant Injector Circuit Low (Bank 2 Unit 1)
The P2056 code means the vehicle's onboard diagnostic system has detected: Reductant Injector Circuit Low (Bank 2 Unit 1). This is a serious severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $300 - $900 (parts and labor)
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Common Symptoms
- Check Engine Light illuminated
- DEF system warning active
- SCR performance reduced on Bank 2
- Possible engine power derate
- Speed restriction may apply
Probable Causes (Ranked by Likelihood)
- Short to ground in Bank 2 DEF injector wiring Very High
- Failed Bank 2 DEF injector coil High
- Water or DEF crystallization at connector Moderate
- Damaged wiring near exhaust components Moderate
- PCM driver circuit fault Low
Step-by-Step Diagnostic Procedure
-
Read freeze frame data for P2056
-
Check Bank 2 DEF injector connector for moisture or crystallization
-
Test wiring for shorts to ground
-
Measure injector coil resistance
Frequently Asked Questions
What does P2056 mean?
P2056 indicates the Bank 2 Unit 1 DEF injector circuit has low voltage, usually from a wiring short to ground or failed injector coil.
Can I drive with a P2056 code?
Short-distance driving only. The Bank 2 SCR system is not functioning properly.
How much does it cost to fix P2056?
Expect $300 to $900 for injector replacement or wiring repair.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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