Diagnosis Conditions

Fig 1: DTC P0138 Diagnosis Conditions

Courtesy of PORSCHE OF NORTH AMERICA, INC.

The DME control module stores DTC P0138 when the sensor voltage is over 1.5V for more than 5 seconds during active oxygen sensing after the TWC.

Fig 2: DTC P0138 Fault Conditions

Courtesy of PORSCHE OF NORTH AMERICA, INC.

NOTE: Diagnosis can be performed with the Porsche System Tester 2 in the Short Test menu.