General

General

IUMPR Statement:
The OBD II System of this test group is designed to comply with the provisions of CCR 1968.2, section (d)(3.2) requirements.

Cold Start Reduction Strategy
The new Cayman S MY 2007 is equipped with a cold start emission reduction monitoring strategy.
The system works as follows:

The Porsche system currently uses a combination of the following measures to enhance the catalyst warm-up:
- spark retard
- elevated idle speed
- retarded transmission shifts, rich lambda during secondary air injection
- camshaft position
- variable valve lift

According to (e)(11.2.1), the individual component related to the above strategies has to be monitored. The table below demonstrates that all catalyst heating measures are covered by components which are monitored individually.The long term fuel system and the valve lift diagnosis, which need a lambda signal for monitoring, are finished after the catalyst warm-up phase. Errors will be detected before the next catalyst warm-up.

Overview:







Monitoring of idle speed
The monitoring of the idle speed is now also active during the cold start phase.

The following P-codes are set in case of an error:
P050D: idle air control system RPM higher than expected during cold start phase
P050A: idle air control system RPM lower than expected during cold start phase

The following chart shows the working principle of the idle speed monitoring: