What does the P0705 code mean?
The P0705 indicates that there is a problem with the transmission range sensor, also known as a transmission gear shifter, which probably makes more sense to you. If the transmission control unit receives a faulty signal from the range sensor, the transmission control unit will send a signal to the engine control unit and it may light up your check engine light.
In most cases, the transmission range sensor is located on the outside of your transmission housing. One or two “wires” emanate from your gear lever and control the gears of the transmission. Instead of having a sensor directly on the gear lever (depending on the car model), the sensor is located on the transmission.
The sensor tells the transmission control unit whether your gear lever is in neutral, parking or driving, etc.
|Code||Description||Common Causes||Possible Solutions|
|P0705||Transmission Range Sensor Circuit Malfunction (PRNDL Input)||Faulty Range sensor/Transmission gear position sensor
Misadjusted Range sensor / Transmission gear position sensor
Faulty wirings to the Range sensor / Transmission gear position sensor
Damaged transmission control unit / engine control unit
|Replace Range sensor / Transmission gear position sensor.
Adjust the Range sensor / Transmission gear position sensor.
Repair faulty wirings
Clean the connector plug to the range sensor
Charge car battery
Replace transmission control unit/engine control unit (Rare)
Because of a safety feature, you can only start your vehicle in neutral or park mode. If the sensor sends a false signal to the transmission control unit, your vehicle, therefore, may not start if there is a problem with the range sensor. In most cases, your transmission may not want to engage the desired gear. Here are some of the most common symptoms.
- No start condition
- Stuck in gear/position
- Check engine light/transmission light
- Wrong/erratic shiftings
- No reverse lights
The most common cause is a defective range sensor, but it can also be the wiring to it or the communication between the control units. Here are the most common causes.
- Faulty range sensor/transmission gear position sensor. (Common)
- Misadjusted range sensor/transmission gear position sensor.
- Faulty wirings to the range sensor/transmission gear position sensor.
- Low voltage
- Damaged transmission control unit/engine control unit. (Rare)
In most cases, the actual range sensor could have internal damage. But if you are lucky, you can try to adjust the sensor a little bit to make it work. I will explain how to adjust it in the “Diagnostics” section below.
- Replace range sensor/transmission gear position sensor.
- Adjust range sensor/transmission gear position sensor.
- Repair faulty wirings
- Clean the connector plug to the range sensor
- Charge car battery
- Replace transmission control unit/engine control unit (Rare)
How to diagnose the P0705 code
This is a guide for quick diagnosis of the P0705 code. I will describe how an automotive technician would perform the troubleshooting. This guide may require some knowledge of automotive electronics and some tools. If you don’t have a lot of knowledge about cars, you can check it and possibly get some tips on how to do it.
Connect a car battery charger
Always connect a car battery charger before troubleshooting. If you work on your car with the ignition switched on when troubleshooting, there is a risk that the battery will drain. A low voltage can trigger further error codes and confuse your troubleshooting. It can also cause damage to your control units and other electronics if you are unlucky.
Connect your OBD2 scanner
An OBD2 scanner that can read the data of the transmission control unit is required and will greatly facilitate troubleshooting. Most of the cheaper ones can only read the generic engine code memory. Check that the OBD2 scanner is compatible with your vehicle model and can read the transmission control unit before you buy a scanner to solve this code.
Check the signal from the range sensor
Check the live data in the transmission control unit with your OBD2 scanner. Check the signal from the range sensor. If the slider is in position, you should receive a “position” value from the range sensor. Check all gears to see if they are correct.
On many cars, you can also check this value in the engine control unit. If possible, also check it to ensure that the connection between the engine control unit and the transmission control unit is correct.
Adjust the range sensor
In many cases an adjustment of the sensor is possible and can solve the problem. Over time, the sensor will wear out and may need to be adjusted. Often you can loosen two or three screws and then turn the whole sensor.
Turn the sensor and check the values you get with your OBD2 scanner. Try to adjust it so that the gear stick matches the value of the sensor.
Measure the wirings
If the sensor settings did not work, you must measure the wiring to the sensor. Check the connector plug for corrosion, and if you find it, clean it and try again. To measure the wiring, you should use diameter and get a wiring diagram for your car model.
In most cases there are about 4-6 different switches in a range sensor. When a gear is engaged, the wire is grounded and the transmission control unit registers it as a gear. But you should always get a wiring diagram for your car.
If you have a wiring diagram, you can also check with a digital multimeter if there are any short circuits or open circuits. To get a wiring diagram, you can either search on the Internet, call your dealer or ask us on our homepage.
Replace the sensor
If you have measured all wires and the adjustment did not help, you should replace the range sensor. After replacing the sensor, you must perform a new adjustment with the OBD2 scanner to ensure that it is good. After the adjustment, clear the error codes and drive for a while to ensure that everything is working properly.
Recommended Tools to Fix P0705
- Read the DTC code memory: FOXWELL NT301 Scan Tool. You may need an OBD2 scanner that can read your transmission control unit for this trouble code
- Car battery charger: NOCO Genius G3500 6V/12V Smart Battery Charger
- To measure the wirings: Digital multimeter
- Contact cleaner to clean connector plugs: Electric Cleaner
- Advanced diagnosing: oscilloscope
If you have further questions about the P0705 code, please comment below and I will answer you as soon as possible. If you have further questions about the car, feel free to ask them on our homepage.