N20 Engine: Repeated Juddering or Surging While Accelerating. The vehicle judders or surges repeatedly while accelerating in hot ambient temperatures between 3,000 RPM and 5,000 RPM. The Service Engine Soon lamp is not illuminated, and no fault codes are stored in the vehicle memory related to this complaint. CAUSE The EPDW (electropneumatic pressure convertor) for the turbocharger wastegate valve is binding internally.
