P0028

DTC P0028 INTAKE VALVE CONTROL SOLENOID CIRCUIT RANGE/PERFORMANCE (BANK 2)

1. OUTLINE OF DIAGNOSIS
Judge NG from Low NG or High NG.
Variable valve lift diagnosis oil pressure switch is attached for diagnosis, ON or OFF of variable valve lift diagnosis oil pressure switch shows whether intake valve is in High mode (increasing the lift amount) or Low mode (decreasing the lift amount).




- Normal condition

- Low NG
Judge Low NG when variable valve lift diagnosis oil pressure switch remains OFF though the intake valve is being shifted to High mode (Oil switching solenoid valve duty: large).

- High NG
Judge High NG when variable valve lift diagnosis oil pressure switch remains ON though the intake valve is being shifted to Low mode (Oil switching solenoid valve duty: small).




2. COMPONENT DESCRIPTION
Variable valve lift system optimizes the lift amount of intake valve with switching low lift cam and high lift cam depending on engine speed. Variable valve system changes the lift amount of intake valve with duty controlling oil switching solenoid valve.




3. ENABLE CONDITION

4. GENERAL DRIVING CYCLE
Perform the diagnosis continuously after 6 seconds from engine starting with controlling of variable valve lift.

5. DIAGNOSTIC METHOD




- Abnormality Judgment
Judge NG when the continuous time of completing the malfunction criteria becomes more than the specified time.




- Normality Judgment
Judge OK and clear NG when the continuous time of completing malfunction criteria becomes more than 3 seconds.

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

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

8. FAIL SAFE
None

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