Air Flow Meter (Code 12)
- Remove Air Flow Meter. Jumper from positive battery lead to air flow meter terminal "E", and negative battery lead to air flow meter terminal "D". Measure voltage between terminals "B" and "D". See Fig 1 . Voltage should be 1.1-2.1 Volts. If voltage is not as specified, replace air flow meter. If voltage is as specified, go to next step.
- With jumpers from battery still connected, blow through air flow meter and measure voltage between terminals "B" and "D". See Fig 1 . Voltage should be 2-4 Volts. If voltage is not as specified, replace air flow meter. If voltage is as specified, replace ECCS control unit.
- Disconnect 16-pin connector. Measure the resistance between terminals 23 and 26. If resistance readings are okay, replace control unit. If not okay, go to next step.TEMPERATURE SENSOR RESISTANCES (OHMS)
Temperature Ohms Above 68°F (20°C) Below 2.9K Below 68°F (20°C) Below 2.1K - If resistance readings are not okay, check harness. Repair if necessary. If harness is okay, dip the sensor into water maintained at listed temperatures and check resistance readings. If no good, replace temperature sensor. If okay, replace control unit.
SENSOR TEMPERATURE/RESISTANCE RELATIONSHIP
| Temperature | Ohms |
|---|---|
| 14°F (10°C) | 7-11.4 |
| 68°F (20°C) | 2.1-2.9 |
| 122°F (50°C) | 0.68-0.1 |
| 176°F (80°C) | 0.26-0.39 |
| 212°F (100°C) | 0.18-0.2 |