A P0705 code is a generic powertrain code that can be triggered in select vehicles built from 1996 onward. This OBD-II code may present common symptoms in different types of vehicles, but diagnosis and repair may vary for each specific make and model.
Diagnostic trouble code (DTC) P0705 code stands for “Transmission Range Sensor Circuit Malfunction (PRNDL Input).” It is triggered when the transmission range sensor cannot send data or provides erroneous input to the transmission control (TCM) or powertrain control (PCM) modules.
The transmission range sensor may also be called the neutral safety switch or PRNDL input. Located outside the transmission box or on the valve body, its job is to communicate the current gear selection or shift lever position with the TCM or PCM.
To learn more about how transmission range sensors work, you can read our in-depth explanation here.
There are two scenarios that could cause a vehicle’s OBD-II system to log a P0705 code. The first is when the TCM and PCM do not receive any information from the transmission sensor at all.
The second is when these modules receive an irrational input from the sensor.
An example could be if the vehicle is running at 70 mph, but the sensor signals the TCM that the car is in park. Likewise, this diagnostic trouble code will trigger if the sensor sends signals that indicate that the vehicle is in multiple gears at the same time.
Here are the common problems that can cause missing/faulty readings from the transmission range sensor:
A P0705 trouble code may cause performance problems that would be noticed by the driver. Below are some signs that you should look out for:
Occasionally, a malfunction in the transmission range sensor circuit may occur without any adverse effects that affect the drivability of your vehicle.
There are a lot of possible causes that could trigger the P0705 code, so diagnosis can get a little tricky especially if you’re not very car-savvy. This is why most people just leave the job to their mechanic.
However, you can still do the job yourself with the help of a detailed guide. Below is a helpful video with more information to help you diagnose the P0705 code:
Disclaimer: Due to the wide variability in vehicle makes and models, as well as other factors, the following information must not be construed as complete or the only definitive way to address a particular issue. Instead, the following content merely attempts to give you a better idea of what a do-it-yourself approach to the issue might involve. You are encouraged to find more technical resources regarding the subject or take your vehicle to a professional technician for the best results.
There’s no one-size-fits-all solution for the P0705 code—just like with most OBD-II codes. Most people simply take their cars to their mechanics and leave the job to them. However, if you feel confident in your DIY skills or are looking to learn more about auto repair, here are some fixes you can try yourself.
Use a scanner to double check the code and confirm if there are other underlying issues. If there’s a persisting error, try and resolve it by checking and replacing the transmission fluid if necessary. As with any code, read and record all DTCs and freeze frame data, then clear the code and drive the vehicle at the same speed and load, etc. to try and recreate the code. This is what mechanics do.
You can also inspect the linkage between the gearshift lever and the gear shifter, since they may need adjustment.
You can try readjusting the transmission range sensor to clear the P0705 code. To do so, you’ll need a transmission range sensor alignment tool and to follow the steps below:
Check the transmission range sensor circuit for any corroding or disconnected wires. More often than not, these are enough to cause the code, so fixing these issues should get rid of the error.
If the code still persists even after trying the fixes above, your last resort should be replacing the transmission control module (TCM) or the engine control module (ECM). To replace the TCM, follow the steps below:
As for the ECM, here’s step-by-step guide on how to properly replace it:
It’s important to note that different vehicles may involve different fixes. For example, replacing the transmission range sensor has been confirmed to work in fixing a P0705 code on a 2011 Ford F-150, XL 5.0L, V8, but doing the same thing may not work for your vehicle.
On vehicles where the Transmission Range sensor is integrated with the Transmission Control Module, some programming may be required, so don’t try that on your own. One way or another, you need to find out everything you can about how your particular TR sensor works and how it is wired. And if that isn’t enough, sometimes the TR sensor is very difficult to access, particularly on front wheel drive vehicles.
Thus, when doing any DIY work on your vehicle, always make sure to consult repair manuals and credible online guides. When you try to “wing it,” you can make a lot of problems for yourself that you didn’t have before.
You can get an ALLDATA single-vehicle subscription, which should give you the information you need for this and any other future repairs your car may need.
To begin with, it bears mention that the automatic transmissions and transaxles in new vehicles, while still mostly hydraulic, have solenoids that facilitate transmission shift functions, and those solenoids are controlled by the vehicle’s Powertrain Control Module (PCM) or by a Transmission Control Module (TCM). The Engine Control Module (ECM) only controls the engine; a vehicle with an ECM and an automatic transmission will have a stand alone TCM. Jeep Cherokees used this setup beginning in the 80s.
On newer vehicles, the ECM and TCM will share pertinent information on the network bus. A PCM controls both the engine and the transmission, but as the demands on the PCM increased with each new model year, manufacturers separated engine and transmission controls into separate modules, thus the TCM.
Okay, whenever there’s a computer controlling the transmission shift points and line pressure, that computer needs to know where the gear selector is at all times. So how does it do that?
Very early model Fords without electronic transmissions only need to know when the selector is in Park or Neutral, so the ECM (Ford referred to it then as a “Processor”), is watching the starter solenoid wire between the ignition switch and the neutral safety switch, which is where the Transmission Range Sensor is on newer vehicles.
When the transmission is in Park or Neutral, the ECM will detect a ground path through the starter solenoid – in any other gear it won’t. That information is used for idle speed control and other load-related functions on those vehicles.
But as solenoids and speed sensors took root in transmissions and transaxles in the 1980s, it became clear that the PCM needs to know exactly where the gear selector is at all times. And the engineers decided how best to do it on their various platforms; it is handled several different ways. We don’t have time to discuss them all, but here are a few.
The Transmission Range Sensor is usually mounted on and keyed to the shift rail, which rotates through shifter detents when you make your gear selection – detents being those places where you can feel the shifter “click” through the gears on the way to the position you want and finally into the one you have selected.
The Transmission Range Sensor is usually mounted on and keyed to the shift rail, which rotates through shifter detents when you make your gear selection – detents being those places where you can feel the shifter “click” through the gears on the way to the position you want and finally into the one you have selected.
–Richard McCuistian, ASE Certified Master Automobile Technician
This could go on for pages, but you get the point. Not all transmission range sensors work the same way, even though they do the same job. Neutral safety and backup light functions are obviously tied to switch position as well.
Ignoring a P0705 code is never a good idea, especially because a faulty transmission range sensor can make it hard for you to shift gears. This can increase your risk of getting into a traffic accident, so it’s best to replace your PRNDL input as soon as possible. Luckily, you can conveniently order a new transmission range sensor here at CarParts.com.
With an easy-to-use interface, CarParts.com takes out all the hassle of buying a quality replacement part. You can rest assured that we only source our transmission range sensors from the best manufacturers in the industry. We also provide accurate and detailed fitment information, so you can find a part with the perfect fit for your vehicle.
Don’t wait for your vehicle to get worse. Fix the issues setting the P0705 code by ordering a new transmission range sensor here at CarParts.com today!
Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.
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