The Check Engine Light is designed to cause an alarm, so you will repair the problem and protect the vehicle from further harm. When you scan the DTCs and find the P0705 code, you may wonder how best to fix it.
In this guide, we cover the meaning of the P0705 trouble code, show you its main symptoms and give you insight into how to fix it. We also cover some diagnostic tips and discuss whether you should keep driving or not.
Code P0705 Definition
P0705 – Transmission Range Sensor Circuit Malfunction (PRNDL Input)
What Does the P0705 Code Mean?
This code reveals that either the Transmission Control Module (TCM) or the Engine Control Module (ECM) has received an error from the Transmission Range Sensor (TRS). The function of this sensor is to tell the module the positioning of the shift lever. This code sets with no input or inaccurate data.
For example, if you are driving 60 mph, but the TRS sends a signal saying that the car is in Reverse, the P0705 DTC will set. The TRS can also claim that the shifter is in more than one gear at a time, which would also throw a code.
The Transmission Range Sensor (TRS) is also known as the Park Neutral Position (PNP) switch, the gear selection switch, the pressure switch or the PRNDL input switch, depending on what car you drive. Cars are designed with three different types of Transmission Range Sensors.
- Contact: Switches that communicate with the module about the shift lever position. It uses a different wire for every position.
- Pressure Range Switch: Bolted directly to the valve body with passages that open or close as the shift lever changes position. When the gear position changes, the passage opens with transmission fluid to alert the sensor.
- Variable Resistor: Each resistor absorbs a particular voltage amount and each gear has its own resistor. When the shifter is in position, voltage is sent out, indicating which gear it is in.
In most vehicles, the TRS is found outside the transmission. Yet, there are some models that put the TRS in the transmission on the valve body.
What Are The Symptoms Of P0705?
It’s very possible that the car will not start once the P0705 condition occurs. After the Check Engine Light comes on, the TRS is going to prevent the car from starting again if it thinks the gear is in anything but Park or Neutral.
Here are the symptoms you may notice.
What Are The Causes of P0705?
It’s highly likely that there’s an electrical problem causing the P0705 code to come on. Here are some of the most possible causes.
- Faulty Transmission range sensor
- Short in the TRS circuit
- Damaged electrical connection
- Misadjusted shift linkage
- Defective valve body
- Bad TCM or ECM
How Serious is the P0705 Code?
Moderate – While the code itself isn’t that serious, you may not be able to shift with this fault. If the car does shift, it may be erratic and you could end up stranded.
Additionally, the vehicle may not start. If it does run, it could go into limp mode at any time, keeping you from accelerating over a certain speed. Finally, even if everything seems to work fine, you could have trouble passing an inspection with the Check Engine Light on.
How Do I Fix the P0705 Code?
The proper fix depends on what’s wrong with the vehicle. You want to perform a complete diagnosis before replacing any parts. After you walk through the steps below, you may find one of these fixes is appropriate.
- Replace the transmission range sensor
- Adjust the shift lever linkage
- Repair short in the TRS circuit
- Repair damaged electrical connection
- Replace valve body
- Update/replace TCM/ECM
Common P0705 Diagnosis Mistakes
It’s easy to jump the gun and start replacing parts to fix a problem. Yet, with the P0705 code, it’s best to perform all of the diagnostics first.
Before replacing any parts, you should check the shift linkage adjustment and ensure the wirings to the transmission range sensor seems good.
How to Diagnose the P0705 Trouble Code?
Even if you aren’t a professional mechanic, there are steps you can take to figure out what’s wrong. As professionals, here are the steps we would take.
- Start by checking the trouble codes with a scanner. Use our online trouble code library to research any other DTCs that are present.
- Check the voltage and ground to the Transmission Range Sensor. Your car service manual will give you instructions to verify the readings. The procedures vary depending on what kind of TRS your car has.
- Use a repair manual to check the shift linkage adjustment to the transmission range sensor. If you have a compatible scanner, the transmission range sensor may need to get reset, depending on the car model.
- Inspect all of the wiring and connections to ensure nothing is damaged or broken.
If you can’t figure out what’s wrong or you need help with the repair, reach out to a qualified mechanic in your area. When it comes to updating or replacing the modules, it’s best to visit a dealership where the programming can be performed.
How Much Does It Cost To Fix Code P0705?
The average repair cost depends on where you have it fixed and what type of car you drive. Here are a few averages to consider.
- Repair short in the TRS circuit – $50 to $350
- Repair damaged electrical connection – $50 to $550
- Adjust the shift lever linkage – $50 to $250
- Replace valve body – $300 to $1,000
- Replace TRS – $100 to $350
- Update/replace TCM/ECM – $250 to $2,500
A Mechanic’s Tips About The P0705 Code
If the Transmission Range sensor on your vehicle is integrated into the Transmission Control Module, it will need some reprogramming if any work is done. You shouldn’t attempt to do this on your own.
The dealership has the right tools and can do all of the programming within about an hour. Save yourself a lot of headaches and let the professionals handle it.
Frequently Asked Questions
Is code P0705 serious?
It isn’t serious if you are still able to shift and drive the car. However, the P0705 code can keep the transmission from shifting into different gears, rendering the car unable to start or in limp mode. You want to repair the problem at the first sign of the code to avoid these conditions from happening.
Can I drive with a P0705 code?
If there are no drivability concerns, you may be able to get the vehicle home without an issue. However, the car could go into limp mode at any time, rendering you unable to drive over a certain speed. Once you turn off the car, you may be unable to restart it if the module can’t determine whether the vehicle is in Park or Neutral.
What happens when a transmission range sensor goes bad?
The module will be unable to tell if the gear shifter is in Park or Neutral, so the engine may not start. You may also have trouble getting the car into gear if it is running. Additionally, the system can throw you into limp mode without any warning, keeping you from being able to accelerate too high.
What causes the transmission range sensor circuit to malfunction?
In some cases, it’s an electrical short or bad connection that needs to be replaced. You may also need to change the transmission fluid and filter if it has become contaminated. Otherwise, there could be a large issue with the valve body, sensor or one of the modules.
How do you reset a transmission sensor?
Without the right equipment, it’s difficult to reset and program modules. If you need programming help, it’s best to visit a local dealership. You may spend an hour or so of labor for the work, but it will be worth it knowing that the vehicle is running correctly.
The P0705 trouble code is not a DTC you want to ignore. At any time, this fault can put your vehicle into limp mode, making it very hard to get where you want to go, especially if you need to drive on the highway. To avoid problems, you would have the fault repaired at the first sign of trouble.
Even pretty competent home mechanics may struggle to figure out the appropriate fix to this problem. If it’s something you aren’t familiar with, we encourage you to reach out to a mechanic in your area for more support.
Categories: OBD Codes
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