Checking the glow plug power supply circuit (Skoda Fabia 6Y)

When checking, the battery must be charged (minimum battery voltage 11.5 V), the engine control unit and the fuse protecting the glow plug power circuit must be in good condition.

1. With the ignition off, disconnect the wiring harness from the coolant temperature sensor, simulating a cold engine.

2. Disconnect the glow plug leads.

3. Connect a voltmeter between the tip of any spark plug and the engine ground.

4. Turn on the ignition; the voltmeter should show a voltage close to the battery voltage for approximately 20 seconds. If the voltmeter shows 0, there is an open or short circuit in the power supply circuit.