Throttle Position Sensor (TPS) & Idle Switch Test

Throttle position sensor and idle switch are a combined assembly located on side of throttle body. Idle switch connector is located on sensor, while TPS connector is a separate harness connected to sensor. Warm engine to operating temperature. On Q45, ensure fast idle cam is fully released. Disconnect TPS at harness. Connect ohmmeter between terminals No. 5 and 6 on sensor side of harness. See Fig 1 .

Fig 1: Testing Throttle Position Sensor
Courtesy of NISSAN MOTOR CO., U.S.A.
On M30, with throttle closed, resistance should be approximately 1000 ohms. With throttle completely open, resistance should be approximately 9000 ohms.
On Q45 with throttle closed, resistance should be approximately 400 ohms. With throttle completely open, resistance should be approximately 5000 ohms.
While slowly changing throttle angle, resistance should smoothly change, with no skips or sudden changes indicated on ohmmeter. If sensor does not respond as indicated, replace TPS. See ADJUSTMENTS article for adjustment procedures.
Reconnect TPS harness connector. Disconnect idle switch connector at TPS. Connect ohmmeter leads between terminals No. 2 and 3 of idle switch harness to sensor.
With throttle fully closed, zero ohm should be indicated. With throttle slightly open, infinity should be indicated. If sensor does not respond as indicated, replace TPS.