P0707
Transmission Range Sensor Circuit Low
If your code reader dashboard displays the generic DTC error code P0707, your vehicle is currently experiencing an active failure related to "Transmission Range Sensor Circuit Low". Proper system troubleshooting is required to safely clear this warning.
Driver's Summary
Your vehicle's computer logged P0707 after detecting a malfunction in the transmission range sensor circuit low system. On the road, this usually shows up as reverse lights don't work, harsh shifting, vehicle starts in gear. You can typically drive short distances, but ignoring this code long-term will cause accelerated component wear and higher repair costs.
Symptoms
Reverse lights don't work, harsh shifting, vehicle starts in gear
Common Causes
- Short to ground in Transmission Range (TR) sensor circuit
- Failed TR sensor (Neutral Safety Switch)
- Water intrusion in the sensor connector
- Misadjusted shift cable
How to Fix
- 1 Repair shorted wiring
- 2 Replace TR sensor
- 3 Clean and dry the connector
- 4 Adjust transmission shift linkage
Technical Explanation
The PCM triggers P0707 after its internal monitoring routine detects that a specific circuit or sensor has exceeded its acceptable operating range. The TCM compares the ratio between input turbine speed sensor and output speed sensor readings against the expected gear ratio stored for each commanded gear position. A deviation greater than a few percent indicates clutch slippage, solenoid malfunction, or internal mechanical failure. Once confirmed, the code is stored as a permanent DTC and the MIL is activated. The freeze frame snapshot — recording RPM, load, coolant temperature, and fuel trim at fault detection — is also saved and is critical for accurate diagnosis.
Is It Safe to Drive?
Code P0707 allows for cautious short-distance driving, but the underlying cause — most likely short to ground in transmission range (tr) sensor circuit — will worsen with time. Fuel economy suffers, and ignoring the fault for weeks can turn a $80 fix into a much larger repair bill.
Mechanic's Pro Tip
The most common mistake with P0707 is replacing the sensor without verifying the reference voltage and ground integrity first. Use a scan tool to monitor the sensor's live output; a truly failed sensor shows a stuck, flatlined reading — a sensor that fluctuates but reads slightly off usually indicates a wiring or vacuum issue, not a dead sensor. Always spray electrical contact cleaner on the connector pins before condemning the sensor.
TR Sensor: $150 - $350