Federal

Fig. 7 Differential Pressure Regulator Test Setup:

1. With the engine cold, turn all electrical consumers OFF.
2. Connect test harness (VW 1315 A/1) between the idle control valve and its harness plug.
3. Connect a multi-meter to the test harness, and set on 2A scale.
4. With the ignition switched ON (engine not running), meter should show 945 - 1055 mA. If not, replace the control unit.
5. Start the engine and warm to normal operating temp.
Idle control current should be 410 - 450 mA.
6. If idle control current is not within specification, adjust using the air by pass screw on the throttle housing.*
Note
If readings are:
455 - 505 (automatic trans),
460 - 510 (manual trans),
Check for open circuit between control unit and ignition coil terminal 1.
* Do not use throttle plate stop to adjust idle.