We understand having disconnected the battery on your Porsche Cayman caused it's Emission Monitors to erase; requiring you drive the vehicle through a drive cycle. Let's briefly explain what emission monitors are. Emission monitors are internal self-tests which the power control module (PCM) performs in order to ensure a vehicle's emission systems, such as the EGR, EVAP, oxygen sensor, O2 heater, and catalyst (catalytic converter) are functioning properly. If any one monitor is incomplete (excluding the EVAP monitor; at the time of this post), your Porsche Cayman will not be able pass the smog test. The EVAP monitor is the only monitor allowed to remain incomplete and the vehicle still pass the smog check because of the difficulty of getting this particular monitor to complete. In order to get the monitors ready for the smog check you'll need to drive your car through a Porsche Cayman drive cycle.
Usually 200-300 miles of driving, and over the course of a few days and in both city and highway traffic conditions, is enough to get the drive cycle complete. Due to individual vehicle owner driving patterns however, sometimes the criteria required to get a particular monitor to initiate and/or become ready is not met. In such instances, it is required that a specific drive cycle pattern which is designed for the Porsche Cayman be followed.
How to Complete a Porsche Cayman Drive Cycle
Performing the driving pattern below will allow your Porsche to make ready all I/M emission monitors in preparation for a smog inspection. Follow the drive cycle carefully. Take extra caution when performing the drive cycle on public roadways. If you feel you will be unable to follow the Porsche drive cycle safely, please seek assistance from an smog check repair station or Porsche dealership. They may be able to perform the drive cycle utilizing a dynamometer, and specialized scan tools; instead of driving the vehicle. Perform the drive cycle at your own risk.
It is best to start the driving cycle in the morning; after a cold soak. A "cold soak" is the act of allowing an engine to cool down overnight. The definition of a cold soak, in engine mechanic terms, is to give the vehicle time to sit at low temperatures, typically below 68°F, or until the internal and external components of the vehicle's engine have had enough time to thoroughly cool down; allowing the PCM to reset the EVAP monitor timer.
Ensure the Check Engine Light is not on.
Gas tank fuel level must be between 15% and 85% during the drive cycle.
Engine temperature requirement is between 68 and 86 degrees F prior to drive cycle start.
START HERE - The Drive Trace:
NOTE: While performing the drive cycle do not exceed 3,000 rpm or 60 mph during any time.
A. Start your Porsche Cayman and let it idle for approximately 2 1/2 minutes. This will allow the ECU to diagnose oxygen sensor aging; meaning the computer will be monitoring the oxygen sensor warm-up period and reaction to rising exhaust temperatures. During this period the ECU is also testing the Secondary Air Injection system.
B. Begin driving. Accelerate to 20-30 MPH and maintain your speed for 3 1/2 minutes. The ECU will be testing catalytic converter efficiency.
C. Next, accelerate to 40-60 MPH. Once again maintain steady speed, this time for approximately 15 minutes. The EVAP system is now being tested along with adaptation range (2) and the oxygen sensor (switching).
D. Decelerate and come to a complete stop. If equipped with a manual transmission, idle in neutral for 3 minutes. If equipped with an Doppelkupplung (PDK) automatic transmission, idle in drive (D) for 3 minutes. Adaptation range (2) is now being tested.
E. Repeat steps B through D. Drive cycle complete.
Should the catalyst monitor and/or the oxygen sensor monitor not complete after completing the drive cycle twice, we recommend having your vehicle inspected by either a Porsche dealer or test and repair certified smog check center. Each of your vehicle's emission monitors have strict input parameters which must be met before the emission monitor test is initiated. For example, if your vehicle's engine never achieves closed-loop, the catalyst monitor will not run. Or, should the ECT (engine coolant temperature) sensor indicate an irregular engine temperature, the air injection monitor may not initiate. Keep in mind that neither of these two conditions may trigger the check engine light on, but they will stop the drive cycle from getting the required monitors ready. Having a repair shop attempt to complete the drive cycle utilizing a dynamometer (eliminating the need for street/highway driving) will allow them to view in real-time all sensor inputs while the drive cycle is in progress. This way they can pinpoint what may be causing your Porsche's emission monitors to not set or the drive cycle not engage.