20-135
If; however, the reed contact closes within 10
seconds, there is a leak. Then, the pump
continues to cycle for four more strokes. The
ECM measures the time for each of these four
strokes until the next time the reed contact
closes. In this fashion, the ECM can
differentiate between "fine" and "large" leaks.
Leak detection is automatically triggered,
shortly after each engine start. If there is an
incorrect measurement, a malfunction is stored
in DTC memory.
A warning will appear on the instrument panel if
the malfunction has occurred during two
successive drives. Also, leak detection can also
be activated using the VAG1551 Scan Tool
Page 20
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11/18/2002 htt
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