With GST

Turn ignition switch ON.
Check voltage between ECM terminal 22 (PNP switch signal) and body ground under the following conditions.

Fig 1: Gear Position Signal Inspection Chart
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 2: Checking Voltage Between ECM Terminal And Body Ground
Courtesy of NISSAN MOTOR CO., U.S.A.
If NG, go to "DIAGNOSTIC PROCEDURE FOR M/T MODELS " or "DIAGNOSTIC PROCEDURE FOR A/T MODELS ".