Combination valve both closed pulse diagnosis
Perform open stuck diagnosis of both combination valves using delivery pipe pressure pulse when both combination valves are closed. Determine which side of valves is stuck open by comparing secondary air flow amount when RH combination valve is closed with that when LH combination valve is closed.
Calculate voltage pulse of the pump delivery pipe pressure when both combination valves are closed. The calculation should be small because there is no pulse from supply pipe pressure with both combination valves closed. When the calculation is large, determine that either of the combination valves is stuck open. Determine which side of valves is stuck open by comparing secondary air flow amount when the RH combination valve is closed with that when the LH combination valve is closed. Air flow amount is larger on the open stuck valve.
- Abnormality Judgment
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
| Malfunction Criteria | Threshold Value | DTC |
|---|---|---|
| Pulse calculation value when both combination valves are closed | > Value from Map 3 | P2440 |
| Airflow amount when the right bank is closed (value from Map 4) | ≥ Air flow amount when the left bank is closed (value from Map 5) | |
| Pulse calculation value when both combination valves are closed | > Value from Map 3 | P2442 |
| Air flow amount when the left bank is closed (value from Map 5) | > Air flow amount when the right bank is closed (value from Map 4) |
Time Needed for Diagnosis: 4000 ms + 992 ms + 992 ms + 992 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.
- Normality Judgment
Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time.
| Malfunction Criteria | Threshold Value | DTC |
|---|---|---|
| Pulse calculation value when both combination valves are closed | ≤ Value from Map 3 | P2440, P2442 |
Time Needed for Diagnosis: 4000 ms + 992 ms + 992 ms + 992 ms