P3105 - FAULT CODE - OBD2

P3105 BMW, MINI: CYLINDER 2 HIGH-PRESSURE FUEL INJECTOR LOW-SIDE CIRCUIT, LOW

From the solenoid-controlled injection valve, high-pressure fuel is delivered to the combustion chamber. This solenoid valve is defined by a retractable plunger, which is flexible in angle and shape, allowing the spray spread pattern to be varied. The discharge orifices are also provided with an injection pattern, thus ensuring uniform fuel distribution.

The function of controlling the injection valve is the solenoid, the retractable piston, a device that is permanently in charge of keeping the propagation properties stable, including the temperatures and pressures of the combustion chamber. The pressure at which the fuel is injected is around 50-200bar in the intake and compression stroke.

When the engine starts to warm up, small amounts of fuel are sent, seeking to get the catalytic converter to reach its operating temperature, and during cold starts, the fuel is sprayed in the compression stroke and through this, the starts are more efficient to the extent of decreasing fuel consumption and pollutant emissions.

When the P3105 OBDII fault code is set, it means that Digital Motor Electronics (DME) found a short ground in the fuel injector circuit corresponding to engine cylinder number 2.

• Check Engine lamp illuminates.
• Misfiring.
• Difficulties when accelerating.

The reasons why the P3105 OBD2 diagnostic code is set are:

• The cylinder 2 fuel injector may have wiring deficiencies.
• The injector 2 circuit connections could have been damaged causing the short circuit.
• The fuel injector for cylinder 2 is possibly faulty.
• The DME may be in bad condition.

The steps to follow to troubleshoot the DTC P3105 OBDII code are as follows:

• Consult the Technical Service Bulletins.
• Inspect the wires and connectors that relate to the fuel injector for cylinder 2. Look for common damage such as wear or burns and if such conditions are discovered, make repairs.
• Take readings of the injector circuit voltages for cylinder 2 and check to see if they match those specified in the data source. If you detect large differences between the actual voltages and the specified voltages, make the appropriate repairs.
• Check the condition of injector 1 for blockages or obstructions. If you determine that it is defective, replace it.