Troubleshooting Hints
- 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 sensor connector.
- 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 incorrect comparison.
- Even if no AFS malfunction occurs, check the mounting direction of the AFS.
TEST SPECIFICATION
| Check item | Check condition | Test specification |
|---|---|---|
| Mass air flow sensor output voltage | Idle RPM | 1.1 ~ 1.8V |
| 2100 RPM at WOT (D-range) | 3 ~ 3.5V |
NOTE:
- When the vehicle is new [within initial operation of about 500 km (300 miles)], the mass air flow sensor air quantity 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 196°F).