P2056 Fault Code

Reductant Injector Circuit/Open Bank 2 Unit 2

• What does that mean?
• Symptoms
• Causes
• Solutions

The P2056 fault code indicates a problem with the reductant injector circuit or an open circuit in Bank 2, specifically referring to Unit 2. This code is commonly associated with diesel vehicles that utilize selective catalytic reduction (SCR) systems to reduce emissions. If the reductant injector is malfunctioning, it can cause the emission control system to fail, leading to increased pollutants being released into the atmosphere.

What are the symptoms of the P2056 code?

Signs of a P2056 code may include:

• Illuminated check engine light (MIL) on the dashboard.
• Poor engine performance or reduced power output.
• Increased exhaust emissions.
• Possible fuel economy deterioration.
• A notification message regarding the SCR system on the vehicle's display.

What causes the P2056 code?

Possible causes for the P2056 code include:

• A faulty reductant injector in Bank 2.
• Open or short circuits in the wiring harness connected to the injector.
• Damaged connectors that may lead to poor electrical connections.
• Issues with the vehicle's engine control module (ECM) or powertrain control module (PCM).
• Contamination or low levels of the reductant (commonly Diesel Exhaust Fluid or DEF).

How to fix P2056?

To resolve the P2056 fault code, the following steps can be taken:

• Perform a diagnostic scan to confirm the P2056 code and check for any additional fault codes.
• Inspect the wiring harness and connectors for any damage or loose connections, and repair or replace as necessary.
• Test the reductant injector in Bank 2 to see if it functions correctly; replace it if it is faulty.
• Ensure that the reductant (DEF) is at an adequate level and free of contaminants.
• If all components appear to be functioning and the issue persists, the ECM/PCM may need to be reprogrammed or replaced.