Start the engine and let it idle.
Connect a voltmeter between the removed idle valve plug and ground.
Switch off the ignition. The instrument should now show the battery voltage within 6-16 seconds (about 12 V), otherwise check fuses no. 2 and 14.
With intact fuses, remove the relay plug (10). The relay is located in the interior behind the bottom cover, next to the steering column.
Switch on the ignition and connect a voltmeter to ground and one by one to terminals 4 and 5 of the relay plug. Then connect a voltmeter to terminals 12 (weight) and 5. The meter should show battery voltage, otherwise check the wires according to the wiring diagram.
Start the engine, plug in the plug on the idle control valve.
Connect terminals 1 and 5 on the relay plug with a short wire. The idle shutoff valve should turn on and the engine should stop. Otherwise, check the wire from terminal 1 to the valve for damage.
If these checks show no problems, replace the idle air shutoff valve relay.