Bosch Denoxtronic 2.2 Wiring Diagram Link

The DCU talks to the Engine ECU (EECU) via J1939.

| Symptom | Likely Culprit Pin(s) | Physical Check | | :--- | :--- | :--- | | | 1, 2, 3, 4 (power pins) | Pull rubber boot back on connector. Look for green/white powder. This burns terminals. | | Intermittent limp mode | 7 (KL15) | Wire breaks near connector strain relief. Wiggle test while reading voltage. | | Can't clear DEF quality fault | 5, 6 (CAN bus) | Check for 60 ohms. If open, unplug downstream components one by one. | | Pump runs constantly / hot | 13 (Pump return) | Ground side shorted to chassis. Pump never shuts off. | | No DEF consumption | 17 (Meter valve+) | Broken wire inside protective loom near the injector. Often hidden. | | Reverse purge fails | 15, 16 | Stuck valve. Apply 12V directly to Pin 15 (+) and Pin 16 (-) – should hear a click. |

Pins 1, 2 are high-current battery supply. Pins 3, 4 are high-current ground. Never swap them—immediate ECU damage. Bosch Denoxtronic 2.2 Wiring Diagram

Contains a diaphragm pump that draws AdBlue from the tank and pressurizes it. Wiring includes power for the pump motor, signals for the internal pressure sensor, and connections for electrical heating elements.

The supply module typically utilizes a multi-pin connector (often a 16-way or similar variant depending on the vehicle manufacturer like Scania or Cummins). Signal Type Description Pump Motor The DCU talks to the Engine ECU (EECU) via J1939

The Denoxtronic 2.2 system operates through three primary electrical and hydraulic modules connected to the vehicle's Engine Control Unit (ECU) or a dedicated Dosing Control Unit (DCU):

If your scanner cannot see the Denoxtronic 2.2 ECU: This burns terminals

The pure Bosch Denoxtronic 2.2 is modified by truck manufacturers: