P0102 (U5/Low Emissions)

DTC P0102 - MASS OR VOLUME AIR FLOW CIRCUIT LOW INPUT

OUTLINE OF DIAGNOSIS
Detect the open or short circuit of air flow sensor. Judge NG when out of the standard value.




COMPONENT DESCRIPTION




ENABLE CONDITION

GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.

DIAGNOSTIC METHOD




Judge NG when the continuous time of completing the malfunction criteria becomes more than 0.5 seconds. Judge OK and clear the NG when the malfunction criteria are not completed.

DTC CLEAR CONDITION
- When the OK idling cycle was completed 40 times in a row
- When "Clear Memory" was performed

MALFUNCTION INDICATOR LIGHT CLEAR CONDITION
- When the OK driving cycle was completed 3 times in a row
- When "Clear Memory" was performed

FAIL SAFE
- Air flow meter: Engine load is normally calculated by manifold pressure and engine speed; however, calculated only by manifold pressure.
- EVAP conc. learning (fuel): Not allowed to learn.
- Knock compensation:
- At normal: learned ignition timing value = knock F/B timing value + whole learning timing value + partial learning timing value
- At trouble: learned ignition timing value = -3 °CA (retard 3 °CA)
- knock F/B timing value = 0 °CA
- Whole learning is not allowed.
- Partial learning is not allowed.
- ISC control: Make the open loop compensation to be the given value (1 g (0.04 oz)/s). Stop calculating the throttle sensor temperature compensation. (Hold the previous value.)

ECM OPERATING AT DTC SETTING
Memorize the freeze frame data. (For test mode $02)