Component Tests and General Diagnostics

1. Mechanical test.
a. Detach intake hose on air flow sensor.
b. Move sensor plate with finger.
c. Sensor plate must move easily through entire range, without touching housing, or binding on its axis.
d. If not, replace the air flow sensor.

2. Electric air flow sensor test.
a. Potentiometer test.
1. Connect an Ohmmeter between terminals 2 and 3.
2. Check resistance while moving sensor plate along its entire travel.
Control unit (ECM) No.
0 280 001 106, 111, 122 70 - 800 Ohms
0 280 001 008 475 - 1900 Ohms
0 261 200 007, 008, 021 475 - 1900 Ohms
b. Air temp sensor test.
1. Disconnect connector from air flow sensor.
2. Measure resistance between sensor terminals 1 and 4 (outer terminals).
3. Resistance should be:
8250 - 10,560 ohms at -9 - -11°C (12 - 16°F)
2280 - 2780 ohms at 19 - 21°C (66 - 70°F)
750 - 910 ohms at 49 - 51°C (120 - 124°F)
4. If resistance values are not within specifications, temperature sensor is defective.

Note: Air temperature sensor is integral with the air flow sensor and cannot be serviced separately. If sensor is defective, air flow meter must be replaced.