1. Disconnect the block with wires from the valve.
2. Connect an ohmmeter to the valve contacts and measure its resistance, it should be 22–30 ohms. If the resistance is not as specified, replace the valve.
3. Check valve power. To do this, connect a voltage indicator with an LED to pin 1 of the block disconnected from the valve and «masses» engine. Turn on the starter, the LED should be on; if not lit, repair the open in the wiring.