1 - Select system test.
2 - Select 'Request large lift'.
If "Valve diagnosis not ready" appears, a fault may have been stored.
1. Erase the fault memory.
3 - Activate the system test with the key F8 immediately before acceleration with wide-open throttle.
The message "Drive link active" then appears.
4 - Perform acceleration with wide-open throttle in 2nd gear, until "Valve lift diagnosis complete" appears.
NOTE:
- If a fault is detected, it is only recorded in the fault memory after 6,000 ignitions (at idling speed approx. 3 minutes waiting time).
- It is important to observe the oxygen sensors during acceleration with wide-open throttle or to record their behaviour with the data logger.
Continue by performing the system test for small lift
Perform system test for small lift
WARNING: Test is carried out while driving. Have a second person operate the Porsche System Tester 2.
System test for small lift means that faults are detected if a valve remains jammed at large lift (fault type: below limit).
Several cylinders may be stored as faulty, although only one valve on one cylinder is faulty. As a rule, only the cylinder bank with the faulty valve
can be detected. Therefore in the case of a fault, the flat-base tappets of the inlet valves of the entire cylinder bank must be replaced.
A faulty flat-base tappet can be detected because the oxygen sensor F(R) for this cylinder bank enriches the mixture (F(R) > 1) during acceleration
with wide-open throttle - see drawing below. Difference from the other oxygen sensor > approx. 15 %. In the case of a fault, the flat-base tappets of
the inlet valves for the entire cylinder bank must be replaced.