Neutral Safety Switch: Description and Operation
Park/Neutral Switch
During the engine crank operation if the park/neutral input is low, with the CAN signal from the transmission indicating park/neutral is selected; the low fault timer is enabled. When the low fault timer reaches the calibrated time, the low fault flag is set. If the park/neutral input is high, and the vehicle is detected as moving with an appropriate engine load, then the high fault timer will be enabled. When the high fault timer reaches the calibrated time, the high fault flag is set.