P0705 Code Symptoms and Causes | How to Fix P0705 Code?

The P0705 code is a generic trouble code that can show in only some specific cars manufactured in 1996 and onward. This code triggers as the transmission range (TR) sensor of your vehicle doesn’t send data or sends insufficient data to the powertrain control module (PCM) or transmission control module (TCM). This article explains the P0705 code symptoms and causes.

P0705 Code Definition

P0705 code stands for “Transmission Range Sensor Circuit Malfunction (PRNDL Input).” 

What does the P0705 code mean?

The P0705 code indicates that your Transmission Control Module (TCM) or powertrain control module (PCM) has received an input error from the Transmission Range Sensor (TRS).

P0705 code

The transmission range sensor (TRS) is also called a PRNDL input switch, gear selection switch, park neutral switch (PNP), or pressure switch. The main purpose of the TRS is to tell the TCM or PCM the shift lever position.

In maximum cases, the transmission range sensor is installed external to the transmission. However, in some cases, it is installed on the valve bodies within the transmission.

The DTC P0705 is set when the powertrain control module doesn’t get sufficient input from the TRS. This code may also trigger if the PCM is getting an input that is logically impossible. For example, if your vehicle is traveling at 50 MPH, but the TRS is telling the PCM that it is in Reverse, then your PCM will immediately trigger the code P0705.

In some cases, the TRS fails until it tells the PCM that it is in multiple gears at the same time. In this case, code P0705 will trigger.

Working of Transmission Range Sensor

The main function of the transmission range sensor is to detect the speed of the transmission. Your car’s PCM needs transmission speed to adjust shift pressure during a shift and determine which gear to engage at what time.

Working of Transmission Range Sensor

Your car’s PCM has the ability to detect clutch engagement and disengagement. It can also read RPM. After receiving all this information from the TRS, PCM performs some specific functions according to the driver feedback.

Some PCMs can store a person’s driving habits in memory and utilize the stored information for a person’s transmission performance.

Causes of P0705 Code

There are multiple causes of the P0705 code, but the following are the most common causes:

  1. Contaminated transmission fluid
  2. Corrode, worn or damaged transmission range sensor wiring or connectors.
  3. Damaged TCM or PCM
  4. Faulty transmission range sensor
  5. Damaged transmission valve body
  6. Defective shift linkage
  7. Dirty external TRS
  8. Misadjusted TRS

Symptoms of P0705 Code

A P0705 trouble code may lead to poor engine performance issues that would be noticed by the driver. When your PCM triggers the P0705 code, it produces the following signs:

  1. Check Engine Light flashing or blinking
  2. Harsh engagement into gear
  3. Delayed shifting
  4. Erratic dash indicators (PRNDL)
  5. Reverse lights don’t switch on
  6. Rough shifting
  7. Failure to put the car into gears
  8. The car starts with the gear selector in a position other than park or neutral

How to diagnose the P0705 code?

You must have the following tools to fix or diagnose the P0705 code:

  1. Multimeter
  2. Advanced program-capable OBDII scan tool
  3. You also have the ability to access the transmission and transmission valve body

Follow the below-given steps to diagnose the P0705 code:

  • The first step is a two person job. One mechanic inspects the TRS for proper voltage and grounding while the other shifts gears. The first mechanic verifies the correct voltage output for each layer while observing a precise voltage within the range fixed by the manufacturer.
  • In the second step, instead of testing the sensor’s voltage output, perform a similar two-person test using the wire harness ends.
  • Similar tests are run on the TRS system’s variable resistor and pressure range switch, and the results give one of several answers: faulty sensor, faulty wiring, or the vehicle’s PCM is faulty.
  • If you think you can diagnose yourself, look up your vehicle’s transmission range sensor specifications and voltage ranges on a website such as ProDemand before testing.

Common P0705 Code Diagnosis Mistakes

When you see a P0705 code, inspect your transmission fluid first. Dirty or contaminated transmission fluid can create all types of ghosting issues with the transmission that store any number of trouble codes. Perform a fluid test before making unnecessary repairs.

How serious is the P0705 code?

  1. The P0705 trouble code is not too much serious, except that it cannot pass an inspection with the check engine light.
  2. It may lead to no start condition along with the check engine light.
  3. Your car can go into emergency mode and cannot exceed a speed of over 40 mph.
  4. It may lead to shifting issues.

Repair Costs for P0705 Code

The repair cost of the P0705 code depends on the labor cost and the repair of the relevant parts.

When your car triggers this code, you may need one of the below-given repairs. For each possible repair, the estimated cost of repair includes the cost of the relevant parts and the cost of labor required to make the repair.

PartsCost
Transmission Range Sensor Adjustment$90
Transmission Range Sensor$90 to $360
Wiring replacement/repair$90 to $1100
Tail Lamp Assembly$190 to $2100
Transmission$1700 to $4600
Valve Body$410 to $1100

FAQ Section

Can I Drive with a P0705 Code?

The severity level of the P0705 code is considered to be moderate. Extended driving with this code can badly damage the internal parts of your car engine. Most commonly, you can drive your vehicle with the P0705 code, but with significant performance problems; therefore, it is strongly not recommended.

What repairs can fix the P0705 code?

  1. Repair an open or short in the TRS circuit
  2. Clean and repair the connections of the external TRS
  3. Change valve body
  4. Replace the damaged or faulty PCM or TCM
  5. Change the transmission fluid
  6. Replacing the transmission range sensor
  7. Replace the transmission filter
  8. Replace defective wiring to the transmission range selector circuit
  9. Adjust shift linkage

What happens when the transmission range sensor goes bad?

The transmission range sensor (TRS) tells the PCM the position of the transmission shifter. The PCM uses this information to control which gears are engaged or disengaged in the transmission. A faulty TRS can cause your car to start in the wrong gear, not be able to upshift or have a situation where you feel like you’re not in gear.

Is the neutral safety switch the same as the transmission range sensor?

The transmission range sensor and neutral safety switch are safety devices used to stop the activation of the starter motor in all gears except Neutral and Park. The TR sensor is part of the starter control circuit and informs the PCM about the current gear selection.

How long does it take to change a transmission range sensor?

It takes about 2-3 hours for the transmission range sensor to be replaced by a professional. If the sensor is in the transmission, the repair may take longer as the mechanic will have to disassemble and reassemble it.

What does a transmission range sensor do?

The main function of the transmission range sensor is to measure the speed of the transmission and sends this information to the PCM. Your car’s PCM uses this information to adjust shift pressure during a shift and determine which gear to engage at what time.

How much is it to replace a transmission sensor?

The average replacement cost of the transmission position sensor is from $260 to $320. In this cost, the costs of the parts are from $120 to $140, while labor costs are between $140 and $170

How many transmission speed sensors are used in a car?

The car is equipped with two transmission speed sensors (ISS and OSS) that work together to display transmission data for the car’s PCM. The ISS sensor monitors the speed of the input shaft. Improper placement of these sensors will affect the operation of the transmission system.

Can ABS sensors affect transmission?

Yes, a bad ABS sensor can cause the transmission to behave erratically or shift incorrectly. The ABS sensor is a wheel speed sensor mounted on each wheel’s hub and reports the speed of all four wheels individually to the ECU.

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