Burn-Off Control System

Testing Air Flow Meter:

1. Remove rubber boot from air flow sensor connector.
2. Check terminal voltages under these conditions:

TERMINAL

B/Y (Power supply)
G/O (Burn-off)
G/B (Air flow mass)
G/Y (Ground)
B/O (Ground)

IGNITION ON

B/Y - Approx. 12 volts
G/O - 0 volts
G/B - 1.0 - 2.0 volts
G/Y - Approx. 0 volts
G/O - Approx. 0 volts

ENGINE RUNNING

B/Y - Approx. 12 volts
G/O - 0 volts
G/B - 1.9 - 5.0 volts
G/Y - Approx. 0 volts
G/O - Approx. 0 volts

3. If not as specified, check wiring harness for an open or short circuit. If a fault is found in the wiring harness, correct the problem. Otherwise, proceed with step 4.
4. Disconnect negative battery terminal and reconnect it.
5. Warm engine to normal operating temperature.
6. Run engine for three minutes at approx. 2,000 rpm in neutral.
7. Turn ignition switch "OFF" and check voltage at the airflow sensor terminal wire (G/O) and terminal (2H) of the ECU. Voltage should be 0V just after the ignition switch is turned "OFF." After 2 - 5 seconds, voltage should momentarily reach 8 - 12V and then return to 0V.
8. If as specified, replace air flow sensor.
9. If not as specified, check voltage at ECU terminals 2P, 2Q, 1I, and related wiring harness. Refer to ECU pin voltage chart in this section under ENGINE CONTROL UNIT (ECU).