Mercedes Sprinter (NCV3, W906) Wiring Diagrams

A complete set of factory electrical wiring diagrams (EWD) for the Mercedes Sprinter NCV3 (W906). An indispensable guide for diagnosing and repairing complex electrical problems. Includes detailed wiring diagrams for all systems: engine (CDI), control units (ECU), AdBlue/SCR systems, CAN bus, ABS/ESP systems, and relay locations.

Mercedes-Benz Sprinter W906 Electrical System. Contains detailed wiring diagrams, electrical component locator information, connector pinouts, and all sensor locations. Includes fuse box and ground diagrams for all years.

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1. Wiring and Connectors

• Door Wiring: Due to frequent opening and closing (especially on cargo and passenger versions), the wires running through the conduits between the body and the doors often break or chafe. This leads to malfunctions of the central locking, windows, or mirrors.
• Contact Corrosion: Connectors under the vehicle, in the wheel arches, and in the engine compartment (especially ABS/ESP sensors and connectors) are susceptible to corrosion due to exposure to salt and moisture.
• Mounting Block Vulnerability: Moisture can penetrate the fuse and relay mounting blocks, causing contact corrosion and erratic malfunctions of various components.

2. Sensor and Control Unit Problems

• ABS/ESP Sensors: Remain vulnerable. Failure of the wheel speed sensors (due to dirt or corrosion) is a common cause of activation of the ABS and GPC warning lights. Mass Air Flow (MAF) Sensor: A dirty or faulty MAF sensor on diesel engines causes a noticeable loss of power and performance issues.
• DPF and EGT (Exhaust Gas Temperature) Sensor Issues: A faulty sensor can prevent the diesel particulate filter from regenerating properly, leading to clogging and the engine going into limp mode.
• PSM (Parameterizable Special Module) Malfunctions: The PSM is often used to connect external equipment (such as a hydraulic auxiliary drive (HAD) or other manufacturer's body electrical system). Problems with the PSM itself or improper connection can cause malfunctions throughout the vehicle's electronics.

3. Specific NCV3 Electronics Issues

• SCR (AdBlue) System: Models equipped with BlueTec often experience issues with BlueTec® exhaust gas aftertreatment system sensors, NOx sensors, or AdBlue pump malfunctions. These malfunctions directly impact engine performance, often including power reduction.
• CAN bus: Due to the system's complexity, problems with one electronic module (such as the driver's door control unit or instrument cluster) can cause errors and malfunctions in other related systems.
• Multimedia issues: Faults in the radio/navigation system or voltage transformer can be related to both the power supply (fuses) and internal components.