AFS uses the features of sensor heater, after HOT FILM units calculate the intake air quantity, then send the signal to ECM.
AFS might be combined to measure the intake air temperature.
When Ignition switch is turned on, if AFS output voltage is not "0" (engine stops), inspect the malfunction of AFS and ECM.
Even it no AFS malfunction occurs, check the mounting direction of AFS.
In case of new vehicle (mileage : below 500km) AFS air quantity is above approx.10%.
Use correct digital voltmeter.
Before inspection, warming up the engine till the engine coolant temperature is up to 80 ~ 90°C.
Inspect the resistance of sensor using a multi-tester.
Measure the resistance between intake air temperature sensor and terminal.
CONDITION | TEMPERATURE (°C) | RESISTANCE (㏀) |
Ignition switch ON | 0 | 5.12 ~ 5.89 |
20 | 2.29 ~ 2.55 | |
40 | 1.09 ~ 1.24 | |
80 | 0.31 ~ 0.37 |
If resistance value is out of standard, replace the intake air temperature sensor (built in AFS) assembly.
