Barometric Pressure Sensor: Testing and Inspection

Fig. 7 Differential Pressure Regulator Test Harness:

Fig. 4 Altitude compensation chart:

1. Connect differential pressure regulator test harness (VW 1315A/1), Fig. 7, and hook up a multi-meter set for 20 mA.
2. Remove the plug from the coolant temp. sensor and connect the terminals together (use adapter VW 1490 or equivalent).
3. Unplug oxygen sensor
4. With ignition switched ON, observe meter reading. Current values should be as shown in Fig. 4.
5. If the current readings are not as specified;
a. Substitute known good altitude sensor.
b. Check for open circuit in wiring between altitude sensor and control unit.
6. If wiring and altitude sensor are OK, replace the control unit.