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P2054 OBD-II Trouble Code: Reductant Injector Circuit Low Bank 1 Unit 2

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P2054 trouble code definition

Reductant Injector Circuit Low Bank 1 Unit 2

What the P2054 code means

This code indicates a problem with the circuit that controls the reductant injector. The terms “circuit low” refers to a lower than expected voltage in the reductant control circuit. This injector injects DEF (Diesel Exhaust Fluid) into the exhaust stream of a diesel motor to reduce the emissions of NOx (Oxides of Nitrogen, aka Nitrogen Oxide).

What causes the P2054 code?

The most likely cause of this code is a shorted reductant injector. The wiring harness to the reductant injector should be inspected closely, being under the vehicle and attached to the hot exhaust system, the possibility of damage is something that should be considered.

What are the symptoms of the P2054 code?

  • Higher than normal NOx emissions
  • Check engine light
  • Though this system should not affect the smooth running of the vehicle, there are reports that some systems are designed to affect the way the system runs. For what reason it is still unclear, as these systems are new to the diesel emissions market.

How does a mechanic diagnose the P2054 code?

  • A technician should first connect a scanner to the vehicle for monitoring and to command on the DEF system.

  • After it has been confirmed that the system isn’t operating as expected, a multimeter should be used to test the resistance of the injector solenoid.

  • If the solenoid resistance is within spec, power and ground should be applied to the solenoid to test it further.

  • If nothing is found wrong with the injector solenoid, the wiring harness should be thoroughly inspected visually and if necessary, continuity of the wiring harness from the PCM to the solenoid should be checked.

  • If everything checks out to this point, the reductant injector should be removed from the exhaust system and checked for clogging, as DEF is corrosive and is a common problem with this system. Although it should be noted this code is designed to detect a fault in the electrical part of this system.

Common mistakes when diagnosing the P2054 code

  • Failure to inspect the wiring harness and connector thoroughly.

  • Failure to confirm the PCM is able to command the system on.

  • Failure to remove and inspect the nozzle for clogging. This code is an indicator of the condition of the electrical circuit, but a clogged reductant injector can cause the sensor to read incorrectly.

How serious is the P2054 code?

Other than contributing to global warming, because the system isn’t working properly, this system in of itself doesn’t affect the vehicle at all. There are reports that some vehicles exhibit drivability issues when this system is failing.

These systems are new to diesel technology, so much is unknown about how each manufacturer's programming will affect the smooth running of the vehicle. Outside of the programming choices the manufactures make when integrating the DEF system into the exhaust stream of a vehicle, this system has no adverse effects on the vehicle.

What repairs can fix the P2054 code?

  • Replacing the reductant injector
  • Repairing wiring to the injector
  • Replacing the PCM (uncommon)

Additional comments for consideration regarding the P2054 code

This code isn’t very common. There are several other codes used by different manufacturers to test this system in the same fashion. The codes numbers all seem to fall into the P2xxx category and differ per manufacturer. Regardless the procedures and operational dynamics are consistent from vehicle to vehicle and utilize the same engineering designs across the board.

Without a doubt, the most common failure is the reductant injector itself. This injector injects a corrosive solution into the exhaust stream that tends to corrode and clog the injector nozzle. The manufacturer’s are still working out the most effective methods of implementing this system design to reduce the emission of NOx. As with any new system to the consumer market, it will take time for the auto industry to discover the lowest maintenance design. Until then, this system is a common thorn in the side of anyone who owns a newer diesel vehicle.

Need help with a P2054 code?

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The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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