When your 2022 Toyota Highlander won't start and you suspect the neutral safety switch (more accurately called the transmission range sensor on modern vehicles), the starting circuit isn't receiving confirmation that the transmission is in Park or Neutral. This safety feature prevents starting in gear but can malfunction.
Understanding the Transmission Range Sensor
The 2022 Highlander uses an electronic transmission range sensor rather than an old-style mechanical neutral safety switch. This sensor tells the ECM the exact position of the shift lever, allowing starting only in Park or Neutral. It also affects shift interlock operation and transmission behavior.
Symptoms of Range Sensor Problems
Beyond preventing starting, a failing range sensor may cause backup lights to stay on continuously, incorrect gear position display on the dashboard, transmission shifting problems, or the vehicle starting in Neutral but not Park (or vice versa).
Testing in Neutral
The simplest diagnostic test is attempting to start in Neutral instead of Park. If the Highlander starts in Neutral but not Park, the sensor has a specific fault in Park position detection. If it won't start in either position, other starting circuit issues may be present alongside or instead of range sensor problems.
Shift Interlock Connection
The same sensor affects the shift interlock that requires brake application before shifting from Park. If you notice the shift interlock behaving strangely - requiring multiple brake presses or not releasing at all - this supports range sensor diagnosis.
Shifter Position Verification
Ensure the shift lever is fully engaged in Park. Sometimes the lever moves without completely engaging the Park position mechanically. Try shifting firmly into Park, possibly even shifting to Drive and back to Park to ensure complete engagement.
Wiring and Connector Issues
Before condemning the sensor itself, check its electrical connections. The range sensor connector can become corroded or loosened, especially in areas with salt exposure or high humidity. Connector cleaning and verification can sometimes resolve intermittent range sensor codes.