Checking the Idle Speed Control Solenoid Valve (VW Passat B4)

The operability of the electromagnetic idle stabilization valve is checked on a warmed-up engine (oil temperature no higher than 80°C), with the engine idle speed correctly adjusted, with a working coolant temperature sensor of the fuel injection control subsystem, and in the absence of air leaks in the engine intake tract.

Turn on the ignition.If the idle speed control valve is working properly, it should vibrate and hum. If this does not happen, disconnect the connector (fig. 2-104) valve and measure the resistance of the valve winding by connecting an ohmmeter to the terminals of the valve block, which for the "RV" engine should be within 3.5-4.5 Ohm, for the "2E" engine - 2-10 Ohm. If the obtained value does not correspond to this, the valves are subject to replacement. Check the integrity of the circuit between the valve and the controller by connecting an ohmmeter to the terminals of the junction block. If the circuit is damaged, replace the controller. Check the control current of the valve. To do this, connect the terminals of the valve block and the junction block with jumpers and connect an ammeter to them. Start the engine at idle speed and after about 1 min bring the engine speed to more than 3000 rpm three times. Measure the control current at idle speed, which, depending on the engine load, should be within 400-1000 mA for the "RV" engine and 400-650 mA for the "2E" engine. Disconnect the coolant temperature sensor connector of the fuel injection control subsystem and measure the valve control current, which should be within 420±30 mA. If the obtained value of the valve control current does not correspond to the norm, replace the controller.