Reductant Injector Circuit Open (Bank 1 Unit 2)
The P2051 code means the vehicle's onboard diagnostic system has detected: Reductant Injector Circuit Open (Bank 1 Unit 2). 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 on
- DEF system malfunction warning
- Incomplete DEF injection coverage
- Elevated NOx emissions
- Speed limiter may activate
Probable Causes (Ranked by Likelihood)
- Open wiring to Bank 1 Unit 2 DEF injector Very High
- Failed DEF injector Unit 2 High
- Disconnected or corroded connector Moderate
- Blown injector circuit fuse Moderate
- PCM driver failure Low
Step-by-Step Diagnostic Procedure
-
Read freeze frame data and confirm P2051
-
Check fuse and relay for DEF injector circuit
-
Inspect Unit 2 DEF injector connector and wiring for open circuits
-
Measure injector coil resistance
Frequently Asked Questions
What does P2051 mean?
P2051 indicates an open circuit in the second DEF injector on Bank 1, meaning that injector cannot deliver diesel exhaust fluid into the exhaust stream.
Can I drive with a P2051 code?
Drive only short distances. Incomplete DEF injection means NOx emissions are not properly controlled.
How much does it cost to fix P2051?
Repair costs typically range from $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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