As noted in our Tips section of May's newsletter, on all OBD2 (1996+) Porsche's, after being serviced, from battery disconnection or erased codes, the car must be driven through a series of "Drive Cycles". If the appropriate number of Readiness Monitors (codes) are not flagged as "Ready", (meaning set as "Not Ready" ) in most cases, the vehicle cannot pass an emissions test, therefore fails state inspection.

When is the vehicle "Not Ready"? And when is it set to "Ready" status that will enable it to pass inspection?

The "Readiness Monitors" or Codes are "Not Ready" when they are reset each time the codes are cleared, or the battery is disconnected, or the ECM is disconnected.
After the appropriate Drive Cycle(s) is successfully completed the vehicle is reset to "Ready" status.

So what IS a Drive Cycle?

A "Drive Cycle" consists of starting the engine, running the engine or driving until oxygen sensing becomes active and stopping the engine. Since stopping the engine cannot be predetermined, the diagnostic routines are started as soon as oxygen sensing is activated.

How do you perform the Drive Cycle?

Completing the Drive Cycle successfully one time should reset most codes to "Ready" status. However, there are two "Trip Monitors" which require that the Drive Cycle be successfully completed two times to achieve a "Ready" status. Furthermore, systems which use averaging, may require the Drive Cycle to be completed more than two times.

Basically, to initiate the Ready status, at least two "Trips" have to be completed. A "trip" is a driving cycle after a rest period that enabled the diagnostic system to monitor all components and systems at least once.

The vehicle should be driven approximately 7.5 miles within a period of approx. 23 mins. from a cold start. Operate the throttle smoothly to obtain the best results. DO NOT turn the ignition off during the drive cycle. There is a total of 16 steps. Click here to see the steps!