Diagnostic Aids

A vacuum leak or a pinched vacuum line may cause DTC 78 to set. Check all vacuum lines and components connected to hose for leaks or sharp bends. Check vacuum source. DTC 32 will set if a problem exists with vacuum source. Also check for proper vacuum line routing.

Fig 1: DTC 78 Schematic ("P" Series) Wastegate Solenoid Fault

Fig 2: DTC 78 Flow Chart ("P" Series) Wastegate Solenoid Fault