Editing AFM (section)

==Problems with the AFM not operating properly==

'''Symptoms'''


# Car refuses to start or car starts but cannot maintain idle
# Car runs sluggish up to about 2000 +/- 200 RPM and then takes off after that
# Car almost cuts out on low throttle 

Many ECCS fault symptoms like above, are common for other ECCS component failures. Symptom 1. above can also be caused by a faulty [[Crank Angle Sensor]], and the Nissan workshop advises to check and clear that component first, when suspecting trouble with the AFM unit - if the connectors for CAS and AFM are in bad condition, it can also cause this symptom. Likewise, symptom 3. above, can also be caused by bad adjustment/failure of the [[Throttle Position Sensor]] idle switch. It is important to check, test, and verify other ECCS components are working correctly, before concluding the AFM is actually the fault.

The above symptoms can also be due to the fact that there is an air leak anywhere between the AFM and the engine, and the ECU is not aware of this 'extra' air. This could be a broken/split hose, or failed hose-clamp.

The reason why 2000 +/- 200 RPM  is so, is because the O2 sensor is able to measure the exhaust gas ratio in this range, and the ECU will attempt to enter closed loop mode. Note that if your O2 sensor is damaged or has failed, the engine might not display this behaviour at all and simply stall if revved past 2000rpm.

When other possible causes of these symptoms are eliminated, they are often due to the failure of the AFM to be able to correctly measure the amount intake of air passing through it. It can also be due to the fact that the hot wire has become badly contaminated.