Trouble Code P0705: Transmission Range Sensor TRS Circuit Malfunction

Your vehicle uses a transmission range switch, or TRS, to communicate the position of your gear shift with your powertrain control module. A TRS circuit malfunction will create trouble code P0705. Learn more about this essential sensor and find out how do I fix trouble code P0705?
What Is a Transmission Range Sensor?
Your powertrain control module needs to know the exact position of your gear shift. Whether you’re in drive, neutral, reverse or park, the TRS communicates this to your powertrain control module or transmission control module, depending on your make and model vehicle. This sensor allows your backup lights and other important electrical features operate correctly depending on the position of the gear shift.
The speed sensor information is compared with the TRS information to determine the correct gear shift position. Error code P0705 is the result of a failure in the circuit. Your powertrain control module either doesn’t recognize the signal or is receiving no signal at all. One possibility is that the speed sensor registers movement while the TRS sensor doesn’t register your vehicle in drive.
Most vehicles are equipped with either an internal or external sensor. Depending on your vehicle, this will make a significant difference in the repair solutions.
Symptoms of Trouble Code P0705
You may still be wondering, what does the code P0705 mean? There are many symptoms that could arise if your vehicle has a damaged or unresponsive TRS. The most common sign is your malfunction indicator lamp being illuminated and error code P0705 being present. However, you may also experience one or more of these symptoms:
- Failure of your backup lights
- Starting in any gear
- Failure to start in any gear
- Irregular shifting
- Reduced fuel economy
Basically, your ignition, lights and gear shift are all failing to communicate properly. As your vehicle is unsure which gear is correct, it may act as if it’s in gear or parked, regardless of the actual position of the gear shift.
Common Causes
Because trouble code P0705 is a sign of a circuit malfunction, the most common causes are electrical. From the TRS sensor itself to the wiring, connectors and wiring harness, you’ll need to carefully inspect the entire length to find any damage.
The sensor itself is prone to corrosion and shorts as it ages. Extreme weather, high mileage or sudden jolts may all cause damage to this inexpensive sensor. Similarly, loose connectors and frayed, broken or burnt wiring can also cause a short in the circuit.
Repair Solutions
First, determine the location of your TRS sensor. Internal sensors are sealed in your transmission. This requires a complete removal and draining of your transmission. While the sensor itself is an affordable part, the entire process is very time consuming and requires expert care.
Check for a bad O-ring seal on internal TRS sensors. O-rings and casing issues are the most common problems. Repair or replace your sensor. Then, you’ll need to replace your transmission. Refer to your service manual for the specific step necessary, or take it to a transmission specialist for accurate repairs.
Thankfully, external TRS repairs are much more convenient. Shift your transmission to neutral, block the wheels, apply the parking brake and find the transmission shift linkage. Carefully remove the electrical connector from your TRS sensor and inspect it for any corrosion or damaged pins.
Inspect the wiring harness and sensor for any signs of damage. Test your TRS sensor to see if it’s working properly. If not, you’ll need to replace your entire sensor. Clear your code and check to see if these repairs solve your OBD-II scanner error code P0705 problem. If not, you may still have an issue with your wiring or your TRS.