Glow plugs (R9) (Mercedes-Benz Vito W639)

The combustion chamber is preheated by glow plugs fed from the output stage of the preheating system. The duration of pre-heating depends on the coolant temperature. When the key is set to position 2, the CDS control unit (6) issues a command to activate the preheating output stage (4) and to switch on the preheating indicator light located on the instrument cluster. The duration of pre-heating is calculated by the engine control unit.

Glow plugs consist of a threaded housing and a heating element built into the housing.

When the glow plug is turned on, a current of 30 A flows through it. At the same time, the heating coil heats up, heating the plug. The control coil limits the current to 15-25 A during heating and limits the spark plug heating temperature, which helps to increase the service life of the spark plugs.

VN 9.036 1. Glow plugs R9; 2. Glow plug 1st cylinder R9/1

VN 9.037 Glow plug heating system; 1. Indicator lamp for pre-heating of glow plugs A1e16; 2. Ignition switch; Ignition key positions:; 0. The key can be removed from the keyhole only in the position; 1. Most electricity consumers are turned on; 2. Pre-heating and driving mode position; 3. Starter engagement position; 3. Coolant temperature sensor B11/4; 4. Glow plug power output stage connector N14/2; 5. Glow plugs R9; 6. Engine control unit N3/9; X1. Contact 1 of connector 14/2: output of information about switching on of pre-heating to the engine control unit (feedback); X2. Contact 2 of connector 14/2: power supply to glow plugs; X3. Contact 3 of connector 14/2: battery supply circuit 30

Placement and connection of glow plugs in the engine