lemon-mirror:
Home >> Jeep >> 2021 >> Cherokee Trailhawk >> Repair and Diagnosis >> Electrical >> Starter >> Starting System (Service Information) >> Sensor, Neutral Position >> Operation

Sensor, Neutral Position: Operation

The purpose of the Neutral Position Sensor (NPS) is to provide an output from the sensor to a controller concerning gear range position. On vehicles equipped with a manual transmission, the shift cable position is interpreted by the controller from the NPS to determine if the transmission is in neutral or in some gear range, for the purpose of determining when the stop/start system can safely restart the vehicle without the clutch pedal being depressed. The switch outputs a Pulse-Width Modulated (PWM) signal whose percentage of duty cycle corresponds to the ranged denoted in ( ) Neutral, in a gear range, or as a fault value. The NPS is attached to shift cable such that it is nominally outputting 50% duty cycle at or when the vehicle is shifted to ( ) Neutral. Higher or lower duty cycle outputs are denoted as the magnet on the shift cable moves with respect to the NPS when the vehicle is shifted to gear range positions.

The NPS receives a reference voltage of five volts, has a common ground and outputs a PWM signal to the controller.

Outputs reading less than 5% or more than 95% of duty cycle will trigger Diagnostic Trouble Codes (DTC). Outputs reading between 5-25% or 75-95% represent in-gear positions and outputs readings between 25-75% represent ( ) Neutral position. Check that the sensor is attached properly to shift cable inside the center console, at the shifter and that the wiring lead is attached to wire harness coming up from the rear of the shifter. Check that the shift cable is properly attached to shifter and transmission ends to levers and load reaction points. With a jumper, voltages from the sensor input and output can be read with a voltmeter and compared with expected values. As an example, 90% of 5 volts is 4.5 volts, so if you read 4.5 volts, the transmission has been shifted into a gear range.

The NPS is not available to order as a standalone component. To obtain the NPS, the shift cable assembly will need to be replaced.