System to release a stuck lock-pin in a cam phaser
View Patent ↗A stuck lock-pin release system for a lock-pin in a cam phaser includes a stuck lock-pin detection module and a stuck lock-pin module that communicates with the stuck lock-pin detection module. The stuck-lock pin detection module periodically determines whether a lock-pin in a cam phaser is in a stuck park condition. When the lock-pin is in the stuck park condition, the stuck lock-pin module alternately biases the cam phaser in a first and second direction until the lock-pin is no longer in the stuck park condition.
1. A stuck lock-pin release system for a lock-pin of a cam phaser, comprising:
a stuck lock-pin detection module that periodically determines whether the lock-pin is stuck in a park condition; and
a stuck lock-pin module that communicates with said stuck lock-pin detection module and that alternately biases the cam phaser in first and second directions when the lock-pin is stuck in said park condition.
2. The stuck lock-pin release system of claim 1 when the lock-pin is stuck in said park condition, said stuck lock-pin module biases the cam phaser in said first direction until a first period has expired and when the first period has expired biases the cam phaser in said second direction until the lock-pin is no longer stuck in said park condition or a second period has expired.
3. The stuck lock-pin release system of claim 1 wherein said lock-pin is stuck in said stuck park condition when the desired cam position is greater than a first predetermined threshold and the measured cam position is less than a second predetermined threshold.
4. The stuck lock-pin release system of claim 1 wherein a stuck lock-pin flag is set while the lock-pin is stuck in said park condition.
5. The stuck lock-pin release system of claim 4 wherein said stuck lock-pin flag is cleared when the lock-pin is no longer stuck in said park condition.
6. The stuck lock-pin release system of claim 1 wherein a counter is used as a timing source when the lock-pin is stuck in said park condition.
7. The stuck lock-pin release system of claim 6 wherein said counter is reset to an initial value when the lock-pin is no longer stuck in said park condition.
8. A method for releasing a lock-pin of a cam phaser that is stuck in a park condition, comprising:
periodically determining whether the lock-pin is stuck in a park condition; and
alternately biasing the cam phaser in first and second directions when the lock-pin is stuck in said park condition.
9. The method of claim 8 further comprising:
when the lock-pin is stuck in said park condition, biasing the cam phaser in said first direction until a first period has expired; and
when the first period has expired, biasing the cam phaser in said second direction until the lock-pin is no longer stuck in said park condition or a second period has expired.
10. The method of claim 8 wherein said lock-pin is stuck in said park condition when the desired cam position is greater than a first predetermined threshold and the measured cam position is less than a second predetermined threshold.
11. The method of claim 8 further comprising setting a stuck lock-pin flag while the lock-pin is stuck in said park condition.
12. The method of claim 11 further comprising clearing said stuck lock-pin flag when the lock-pin is no longer in said park condition.