1 Fuel feed to the high-pressure pump
2 Water drain screw
3 Electric fuel pre-heater
4 Fuel feed from the fuel tank
The fuel filter clipped into transmission end of the
cylinder head is equipped with an electric fuel heater. There is a water drain screw in the top housing section of the filter for draining purposes. In accordance with the service intervals, the fuel filter must be drained of water regularly.
1 Battery junction box
2 Fuel heater relay
3 Fuse (10A)
4 Fuse (15A)
5 Ground
6 Electric fuel heater in the fuel filter
7 Ground
The electric bi-metal controlled fuel heater works independently of the PCM. It is actuated via a fuel heater relay when the ignition is switched on (ignition ON). However, the activation of the heating element is dependent on the current temperature. Below a fuel temperature of 0 to โ4 ยฐC, the circuit is closed by the bi-metal and the heating element is energized. The bi-metal opens the circuit at a fuel temperature between 1 and 5 ยฐC and ends the heating phase.
Possible causes of faults
Fuel filter may be blocked by dirt. Air may also enter the low-pressure system as a result of leaks in the fuel filter.
Effects of faults
Poor engine starting when warm or cold
Irregular idling
Engine does not start.
Engine starts, but cuts out again immediately afterwards.
Engine has insufficient power.