P0129

DTC P0129 - BAROMETRIC PRESSURE TOO LOW

OUTLINE OF DIAGNOSIS
Detect the malfunction of atmospheric pressure sensor output property.
Intake manifold pressure and atmospheric pressure are the same from turning the IG key to ON to turning the start SW to ON. Therefore, compare the pressure from intake manifold pressure and atmospheric pressure sensors, and then judge NG when their difference is large.

COMPONENT DESCRIPTION
Atmospheric pressure sensor is built in ECM.




ENABLE CONDITION

GENERAL DRIVING CYCLE
Perform the diagnosis only once from the IG key turned to ON to the start SW turned to ON.

DIAGNOSTIC METHOD




Judge NG when the continuous time until completing the malfunction criteria becomes more than the time (0.2 seconds) needed for diagnosis. Judge OK when the malfunction criteria are not completed.

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

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

FAIL SAFE
Make the atmospheric pressure 101 kPa (760 mmHg, 29.8 inHg).

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