What does the P0705 code mean?
The P0705 indicates that there is a problem with the transmission range sensor, also known as the transmission gear lever,
which probably makes more sense to you. If the transmission computer receives a faulty signal from the range sensor, the transmission computer will send a signal to the engine computer and it may turn on your check engine light.
In most cases, the transmission range sensor is located on the outside of your transmission case. One or two “wires” come from your gear lever and control the transmission gears. 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 computer whether your gear lever is in neutral, park, or drive, etc.
P0705 Symptoms
Due to a safety function, 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 may therefore 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 starting condition
- Stuck in gear/position
- Check engine light / transmission light
- Incorrect/erratic shifting
- No reverse lights
Possible Causes
The most common cause is a faulty range sensor, but it could 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 transmission range / gear position sensor.
Faulty wiring to the range sensor / transmission gear position sensor.
Low voltage
Damaged transmission control unit / engine control unit. (Rare)
Possible Solutions
In most cases, the actual range sensor may have internal damage. But if you’re lucky, you can try adjusting the sensor a bit to make it work. I will explain how to adjust it in the “Diagnostics” section below.
Replace the range sensor / transmission gear position sensor.
Adjust the range sensor / transmission gear position sensor.
Repair faulty wiring
Clean the range sensor connector plug
Charge the car battery
Replace the 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 certain tools. If you don’t have much knowledge about cars, you can check it and possibly get advice 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 on during troubleshooting, there is a risk that the battery will discharge. Low voltage can trigger other error codes and disrupt your troubleshooting. It can also damage your control units and other electronic devices if you are unlucky.
Connect Your OBD2 Scanner
An OBD2 scanner capable of reading transmission control unit data is necessary and will greatly facilitate troubleshooting. Most cheaper ones can only read generic engine code memory. Check that the OBD2 scanner is compatible with your vehicle model and can read the transmission control unit before purchasing a scanner to solve this code.
Check the Range Sensor Signal
Check the live data in the transmission control unit with your OBD2 scanner. Check the range sensor signal. If the lever 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 computer. If possible, also check that the connection between the engine control unit and the transmission control unit is correct.
Adjust the Sensor
In many cases, sensor adjustment 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 rotate the entire sensor.
Rotate the sensor and check the values you get with your OBD2 scanner. Try to adjust it so that the gear lever matches the sensor value.
Measure the Wiring
If the sensor settings do not work, you need to measure the sensor wiring. Check that the connector plug is not corroded and if you find it, clean it and try again. To measure the wiring, you need to use the pinout and obtain a wiring diagram for your car model.
In most cases, there are about 4 to 6 different switches in a range sensor. When a gear is engaged, the wire is grounded and the transmission control unit records 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 for any short circuits or open circuits. To get a wiring diagram, you can either search the internet, call your dealer, or ask us on our homepage.
Replace the Sensor
If you have measured all the wires and the adjustment did not help, you need to replace the range sensor. After replacing the sensor, you need to perform a new adjustment with the OBD2 scanner to ensure it is good. After adjustment, clear the error codes and drive for a while to ensure everything is working properly.