P2056: Reductant Injection Valve Circuit/Open Bank 2 Unit 2
What to do
Inducement deadline applies. If faults are reported for more than one injector at the same time, ask for the shared wiring and supply to be checked before any injector is replaced — these are expensive parts and one damaged loom can implicate several of them.
What this code means
A circuit fault in the second dosing point on bank 2 — the fourth and last of the injector positions the standard defines, and found only on the largest installations.
Where several injector circuits fault together, the shared-cause reasoning that runs through the whole corpus applies with particular force here: these injectors are often fed from a common supply and their harness runs the length of the underbody together. A single chafed loom or one corroded shared connector takes out several at once, and chasing four expensive injectors individually is the wrong response to that picture.
Likely causes
Start here
- Road damage to underfloor wiring · moderate
- Corroded or loose connector · easy
- Faulty reductant injector · specialist
Less common
- Crystallised reductant deposits · specialist
- Open circuit in injector wiring · moderate
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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- The car — make, model, year and engine. The same fault behaves differently on each.
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