With GST

Turn ignition switch ON.
Start engine and warm it up to normal operating temperature.
Select MODE 1 with GST.
Check the mass air flow sensor signal with MODE 1.
Check for linear mass air flow sensor signal value rise in response to increases to about 4, 000 RPM in engine speed.

Fig 1: Selecting Mode 1 With GST

Courtesy of NISSAN MOTOR CO., U.S.A.