Federal
Fig. 7 Differential Pressure Regulator Test Setup:
1. Perform test with engine at normal operating temperature, and all electrical consumers OFF.
2. Connect test harness VW 1315A/1, Fig. 7, between idle control valve and the cars harness plug.
3. Connect a multi-meter to the test harness. Set meter for 2A.
4. With A/C off, and engine at idle, meter reading should be 410 - 450 mA.
5. Adjust if necessary using the air by pass screw on the throttle housing.*
6. With A/C ON, meter readings should be:
480 - 520 mA (automatic trans)
470 - 510 mA (manual trans)
Note; Do not use throttle plate stop to adjust idle speed.