P0068 (U5/Low Emissions)

DTC P0068 - MANIFOLD PRESSURE SENSOR RANGE/PERFORMANCE

OUTLINE OF DIAGNOSIS
Detect the malfunction of intake manifold pressure sensor output property. Judge NG when the intake air pressure AD value is Low whereas it seemed to be High from the viewpoint of engine condition, or when it is High whereas it seemed to be Low from the engine condition.




COMPONENT DESCRIPTION




ENABLE CONDITION

GENERAL DRIVING CYCLE
Perform the diagnosis continuously after idling.

DIAGNOSTIC METHOD




- Abnormality Judgment
Judge NG when either Low side or High side becomes NG. Judge NG when the continuous time of completing the malfunction criteria becomes more than the predetermined time.




- Normality Judgment
Judge OK and clear the NG when both Low side and High side become OK. Judge OK when the malfunction criteria are 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
- Intake manifold pressure sensor process: Estimate the pressure from engine load.
- ISC feedback: Not allowed to calculate the amount of feedback.
- Heavy fuel judgment: Not allowed to carry out the heavy judgment.
- Fuel cut control: Perform fuel cut when intake manifold pressure sensor is NG. (When fuel injection is large.)

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