Mis-diagnosing a Porsche Generator
This bulletin applies to 2007 and later Porsche Boxster, Cayman and Carrera vehicles. Porsche notes that they have discovered that generators replaced and returned under warranty have been found to be functioning correctly.
As of model year 2007, the generator has a charge voltage of between 12.0 and 16.0V and must be evaluated as functioning correctly in this range. The DME controller temperature is always checked before measuring the voltage.
Controller temperature must be at a max of 135 degrees C for the measurement. If this temperature is exceeded, an incorrect measured voltage value will be determined.
A measuring device which shows the voltage as a digital number or an analog pointer display must be used to measure voltage. The measuring device is connected directly to the generator.
Mechanical or electrical generator faults will be stored as fault codes in the DME control unit (fault code P1694 to P1699). Fault codes for under or over voltage (P1694 or P1695) can also occur temporarily due to driving and environmental conditions.