Check conditions: Engine must be cold (chilled to ambient temperature). The battery must be fully charged. Its voltage must be at least 11.5 V.
Checking the presence of current in the circuit
This check can be carried out without removing the glow plugs.
Switch on a test lamp in parallel between the glow plug supply rail and ground.
Turn on the ignition. Turn on preheat. Put the ignition key in the preheat position, observing the control lamp.
The control lamp should light up and go out after a few seconds.
If there are irregularities in the supply of glow plugs, the plug control unit should be checked in a specialized workshop.
Checking glow plugs
Remove connecting cable and power bar.
Connect an ohmmeter in series to each of the glow plugs and check that there is no interruption in the circuit between the cylinder block and the glow plug connectors.
If the electrical circuit is not damaged, then the glow plug is damaged. Replace spark plug. Plug tightening torque 13 Nm.
Attention: The specified tightening torque must not be exceeded. Otherwise, the candle may be damaged. Be careful not to get fuel or oil on the spark plug.
Connect the cable and power mud.
Attention: If no faults are found, and the engine does not start well, visually check the spark plug during the preglow process. To do this, remove the nozzles and inspect the glow plugs through the holes.
Glow plugs with burnt cores
Burnt spark plug cores are the result of damaged injectors.
When such candles are found (arrow) not enough to replace them. It is necessary to check the injectors for injection pressure and tightness (work of a specialized workshop).