Airflow Meter Test - Code 12
- Disconnect 16-pin connector and connect terminal No. 26 to ground with a jumper wire. Turn ignition to the "ON" position and measure voltage between terminals No. 31 and 26. Voltage should be 0.6-1.0 volts. See Figure .
- If voltage is good, go to next step. If voltage is no good, check harness for continuity. If okay, go to next step. If no good, turn ignition switch to the "ON" position and measure voltage between terminals No. 26 and 27. Battery voltage should be detected. If okay, go to next step. If not, repair harness.
- Disconnect airflow meter connector. See Fig 1 . Apply battery voltage to terminals B and C. Measure voltage between D and C. Voltage should be 0.6-1.0 volts. If no good, replace airflow meter. If okay, go to next step.
- Remove airflow meter. Apply battery voltage to terminals B and C. Blow air through airflow meter and measure voltage between terminals D and C. Voltage should be 1.8-2.2 volts at 66 lb. (30 kg) per hour of airflow. If not correct, replace airflow meter. If voltage reading was as indicated, replace control unit.
- Turn ignition switch to the "OFF" position. Disconnect ECU 16-pin connector and measure the resistance between the following terminals: 26-30, 26-31, 30-31, 36-26, 36-30, 36-31. Resistance should be infinite. Connect airflow meter harness connector terminals C, E and F with a lead wire and measure the resistance between terminals No. 26-30, 26-31, and 30-31. Resistance should be zero ohms. If not, repair or replace harness. If okay, go to next step.
- Remove airflow meter. Apply battery voltage to terminals D and E. Measure voltage between terminals B and D. See Fig 1 . Voltage should be 1.1-2.1 volts. If no good, replace airflow meter.
- If okay, blow through airflow meter and measure voltage between terminals B and D. Voltage should be 2-4 volts. If okay, replace control unit. If no good, replace airflow meter.
AIRFLOW METER RESISTANCE VALUES
| Terminals | Resistance |
|---|---|
| E to B | Anything But 0 Or Infinity |
| E to C | 100-400 Ohms |
| E to D | 200-500 Ohms |