Powertrain, generic (extended)

P2059 Reductant Injection Air Pump Control Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

The air that atomizes DEF in an air-assisted system comes either from a small dedicated compressor or from an existing compressed-air system through a supply valve. P2059 concerns the driver circuit of that pump or valve, above all an open circuit: the output is switched on but no current flows. Deutz uses the code on its EMR L1 controller for the air pump or air supply valve (SPN 5796) with several failure types: -00 open circuit, -19 critically high output current, -31 load shorted and -2A unspecified electrical fault, while P2060 and P2061 cover high-side shorts to ground and battery. A blown fuse, a broken coil, an unplugged valve or corroded pins are typical. Without atomizing air the controller cannot dose DEF and NOx rises.

Likely causes

Open coil in the air valve or pump motor
Connector unplugged or corroded, wire broken
Fuse or relay in the supply path failed
Shorted valve coil causing overcurrent shutdown

Symptoms

  • Emission warning lamp on
  • No DEF dosing, NOx rises
  • Power derate on trucks and machines

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€100–700
Time0.5–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

reductant air pumpreductant air pump relay

Related codes

P2060P2061P2037

References: serdia.deutz.com, energy.gov, law.cornell.edu.