The transmission range sensor tells the transmission and engine computers which position the shift selector is in: park, reverse, neutral, drive or a manual range. It is also called the neutral safety switch, park/neutral position switch, PRNDL switch or, on Ford vehicles, the manual lever position sensor. It lets the starter work only in park or neutral, turns on the reverse lights, drives the gear indicator and tells the transmission which range to shift in.
Bad transmission range sensor symptoms
- No start in park while the engine starts in neutral, or the other way around
- Engine starting in gear, which is a safety hazard
- Gear indicator blank, flashing or showing the wrong position
- Reverse lights not working, or staying on
- Harsh or wrong shifting, or limp mode; see limp mode
- Codes P0705 or P0706, sometimes with P0700
Where is the transmission range sensor?
On many vehicles it mounts on the outside of the transmission case where the shift cable or linkage connects to the shift shaft, which leaves it exposed to road water, salt and heat. Some transmissions mount it internally on the valve body, which means removing the transmission pan to replace it.
How to diagnose it
- Read codes with a scan tool that reads the transmission module.
- Watch the range reading on the scan tool while moving the selector slowly through every position; it should match exactly with no flicker or in-between readings.
- Check the shift cable or linkage adjustment; a stretched or misadjusted cable makes a good sensor read wrong.
- Inspect the connector for corrosion and the sensor for water intrusion.
Adjusting or replacing the sensor
Many external sensors have slotted mounting holes and are adjusted with the selector in neutral, often using an alignment tool or a drill bit through an alignment hole. After any shift cable work or transmission replacement, confirm the sensor is adjusted so the engine starts only in park and neutral. Test the start function in every position before driving.
Range sensor vs other transmission faults
A range sensor fault can cause harsh or wrong shifting that looks like internal damage. Fix the range signal first, then check whether shifting returns to normal. If the transmission still slips or flares with a good range signal, see transmission slipping, transmission solenoid symptoms and transmission control module, and compare replacement units on our transmissions page; what transmission do I have? helps you identify yours.
More guides: transmission won’t shift · shifter stuck in park · car won’t move in drive · bad starter symptoms · E4OD problems · bad transmission speed sensor symptoms · bad TCM symptoms.
Trouble codes: P0707 Range Sensor Circuit Low · P0708 Range Sensor Circuit High · P0709 Range Sensor Intermittent · P0850 Park/Neutral Switch Input · P0851 Park/Neutral Switch Low · P0852 Park/Neutral Switch High · all OBD2 codes.
Shipping is a flat $80.00 per order to US addresses, with 15-day free returns. Questions? Ask a parts specialist.