If the engine stalls occasionally, start the engine and shake the MAF sensor harness. If the engine stalls, check for poor contact at the MAF sensorconnector.
If the MAF sensor output voltage is other than 0 when the ignition switch is turned on (do not start the engine), check for a faulty MAF sensor or PCM.
If the engine can idle even if the MAF sensor output voltage is out of specification, check for the following conditions;
● Disturbed air flow in the MAF sensor, disconnected air duct, and clogged air cleaner filter. ● Poor combustion in the cylinder, faulty ignition plug, ignition coil, injector, and low compression. |
Even if no AFS malfunction occurs, check the mounting direction of the AFS.
Check item | Check condition | Test specification |
Mass air flow sensor output voltage | Idle rpm | 0.5V |
2000 rpm | 1.0V |
When the vehicle is new [within about 500 km (300 miles)], the mass air flow sensor reading will be about 10% higher.
Use an accurate digital voltmeter.
Before checking, warm up the engine until the engine coolant temperature reaches 80 to 90°C (176 to 198°F).
