Reductant Injector Circuit/Open

What it means

P2056 means the engine control module cannot detect current flow in the Reductant Injector Circuit circuit: the circuit is electrically open somewhere between the module, the connector and the component.

This entry is compiled automatically from the standard definition and typical diagnostic practice for this type of fault. A detailed, reviewed article is in preparation.

Symptoms

• Check engine light on
• Rough or unstable idle
• Hesitation or poor acceleration
• Increased fuel consumption
• Possible limp mode with reduced power

Common causes

1. Damaged, chafed or corroded wiring in the Reductant Injector Circuit circuit
2. Corroded, loose or water-damaged connector terminals
3. Failed Reductant Injector Circuit component (sensor, solenoid or actuator)
4. Poor ground connection for the module or component
5. Faulty control module driver (rare, confirm all else first)

How to diagnose

1. Read freeze frame data and note when the code set (cold start, under load, after rain)
2. Inspect the Reductant Injector Circuit connector for bent pins, corrosion and water; wiggle the harness with the engine running and watch live data
3. Measure supply voltage and ground at the connector with the key on
4. Check the signal wire for shorts to ground or battery and for continuity to the control module
5. Test or substitute the Reductant Injector Circuit only after wiring and connectors are confirmed good
6. Clear the code and complete a drive cycle to confirm the repair

Related codes

Nearby codes in this group

• P2055Reductant Injector Circuit High
• P2057Reductant Injector Circuit Low
• P2054Reductant Injector Circuit Low
• P2058Reductant Injector Circuit High
• P2053Reductant Injector Circuit/Open
• P2059Reductant Injection Air Pump Control Circuit/Open
• P2052Reductant Injector Circuit High
• P2060Reductant Injection Air Pump Control Circuit Low