P0705: Transmission Range Sensor Circuit Malfunction (PRNDL Input)

You see the P0705 code on your scan tool and don’t know what to do? Is it safe to drive without fixing the underlying problem?

Let’s take a brief look at the code below to go through your situation!

• P0705 Definition: Transmission Range Sensor Circuit Malfunction (PRNDL Input).
• Code Type: Generic – P0705 indicates the same problem whether you’re having a Nissan, Mercedes, or Ford etc.
• Can I Drive with the P0705 code? Yes but not for long. Have it fixed immediately to avoid internal engine and transmission damage.
• Is it easy to fix? Intermediate-advanced level.
• Cost: $250 – $350 (common).

Now, you know something about your situation but, what next?

To save you some time, click on the images below to get a deep insight of the P0705 code.

Table Of Content

Meaning

Causes Identification

Causes, Symptoms, & Fixes

Repair Cost

What Does The P0705 Code Mean?

The fault code P0705 means Transmission Range Sensor (TRS) Circuit Malfunction. It is set when the sensor can not transmit correct data to the transmission control module (TCM) or powertrain control module (PCM).

What Is The TRS?

The Transmission Range Sensor (TRS) is located outside the transmission box or on the valve body. It tells the PCM the location of the shift lever and  helps the controller decide which gear to engage at a specific time.

Car owners also call TRS a pressure switch, Park Neutral Position switch (PNP), the gear selection switch, or a PRNDL input switch. 

What Happens When The TRS Sends Incorrect Signals?

When the TRS fails, it sends incorrect input signals to the PCM.

For example, you’re driving at 60mph. However, the PCM records that your car is in the Reverse Position from the TRS. This causes wrong gear starts or no upshifts. You will possibly perceive this as a falling out of gear condition.

There are several causes that can lead to P0705.

Each has its own solution.

Let’s dive in for more details on possible causes and symptoms of P0705.

P0705 Causes Identification: Quick View

Usually, the P0705 code appears alone, or sometimes, may come along with other fault codes. That depends on what caused the problem.

Check out the table below for possible combinations and what they mean.

Note: The causes for each code combination are the most common ones. There can be some uncommon issues hidden under those codes

P0705: Causes, Symptoms, And How To Fix

P0705’s symptoms depend on the causes. With that information, you can know what to look for when performing the diagnosis. 

Let’s break it down for easy understanding.

Cause #1: Faulty TRS

As mentioned, TRS records transmission information that TCM or PCM needs to control the shifting pressure when changing gears. If TCM or PCM becomes faulty, wrong data reaches the control modules. That leads to problems changing gears at the right time and many other symptoms.

Faulty TRS symptoms:

• P0705 and P0706/P0707/P0708/P0709 code activated.
• Delayed shifts.
• Hard shifts.
• Limited gear operation.
• Random shifting between gears.
• Transmission suddenly shifts to neutral.
• Slow acceleration.

You can fix the problem by replacing the TRS. Normally, a mechanic should spend 2 – 3 hours to finish the process, but for a TRS sensor located inside the transmission box, it may take much longer.

Cause #2: Open Or Short In The TRS Circuit

An open or short TRS circuit means the TCM or PCM will not get the correct transmission data. Once again, the control modules will not know the correct position of the gears and when to shift to an up or lower gear.

Open or short in the TRS circuit symptoms:

• P0705 and P0706/P0707/P0708/P0709 code activated.
• Malfunction indicator lamp comes on.
• Difficulty shifting gears.
• Failure to activate the starter.
• Erratic shift RPMs.
• Poor fuel economy.
• Delayed engagement in automatic transmission.

Repair open or short in the TRS circuit to solve this problem. This action is not quite complicated so you can totally do it by yourself.

Cause #3: Faulty Transmission Valve Body

The valve body is the brain of automatic transmissions, sending signals to engage the clutch and shift

gears appropriately. If it malfunctions, P0705 might be triggered. Fortunately, this component doesn’t fail quite often. 

Faulty transmission valve body symptoms:

• Gear changing problems.
• Slipping transmission.
• Banging or knocking sound.
• Unable to downshift.
• Check engine light on.

A faulty valve body requires replacement right away to prevent any further damages. This is not an easy task so I recommend you to have your car fixed by professional mechanics.

Cause #4: Misadjusted Park/Neutral Position Switch

The Park/Neutral Position Switch only allows you to start the engine when the automatic transmission is in either Park or Neutral. It is a safety feature that prevents the engine from starting when the transmission is in gear. 

The Misadjusted Park/Neutral Position Switch can cause P0705 or a combination of the P0705 code with P0706/P0707/P0708/P0709.

Misadjusted Park/Neutral Position Switch symptoms:

• Engine not cranking in park or neutral.
• Engine cranks when transmission is in any gear.
• Gears fail to shift appropriately.

The solution to this problem is to readjust the Park/Neutral Position Switch. The repair cost to get it done is quite affordable even you carry out the job by yourself or go to the mechanic shop.

Cause #5: Dirty Transmission Fluid

If transmission fluid gets dirty, it fails to lubricate or cool gears. This causes transmission overheating, which can also affect the cooling ability of the engine and functions of PCM/ECM. 

This problem often triggers P0705 and P0897 codes to pop up together.

Dirty transmission fluid symptoms:

• Humming or clunking noise.
• Shuddering or shaking.
• Burning smell.
• Gear slippage.
• Transmission overheating.
• Gear shifting problems.

Transmission fluid turning into brown means that it is dirty, contaminated, and oxidized. The only solution is changing it, which involves draining out the old one and refilling the system with the recommended transmission fluid.

Cause #6: Faulty TCM

It is rare for the transmission control module (TCM) to become faulty. The TCM is the part that takes the responsibility for smooth change in current gear to make your driving experience the best.

Moreover, this control module is also in charge of sending OBD2 codes to your car’s computer if it detects any issues within your car’s transmission. And the P0705 code is one of those codes popping up on the scanner tool as a warning sign.

Faulty TCM symptoms:

• Stalling between gear changes.
• Failure to change gears.
• Transmission not downshifting when you’re at a stop.
• The car is stuck in neutral.
• Transmission not upshifting when accelerating.

Most causes of TCM problems are related to bad connections that a qualified automotive electrician can help you repair. It may also require replacement if permanently damaged. 

How Much Does It Cost To Fix The Code P0705?

The P0705 code is most commonly caused by a faulty transmission range sensor, which typically costs $250-$350 to replace at an auto repair shop. On the other hand, if it is a faulty valve body, your budget should be about $300-$1,000. 

Read the table below for more information.

The Estimated Repair Cost Of P0705

Note: The data in this table is collected in June 2022. The actual price depends on many factors, such as your car’s make and year, mechanic’s rate, etc. 

You Ask, I Answer

Although the P0705 code is not that serious, this fault will affect the drivability of your car so have your car fixed as soon as possible.

Let us know if you have encountered the P0705 code and how you fixed it.

If you have any other questions related to this error code, feel free to leave a comment below, I’ll answer them all!

Thank you!

Read more: The 9 Best OBD2 Scanners for 2022: The Only Review You Need