P0715 OBD-II Trouble Code Symptoms and Causes | How to fix P0715?  

Vehicles have multiple sensors to monitor the performance of the various engine and transmission parts. Your vehicle’s PCM gets information from these sensors to ensure the efficient operation of the various vehicle components. The input or turbine speed sensor is one of the major sensors of the transmission. When the input speed sensor fails, the powertrain control module (PCM) triggers the code P0715. This article primarily focuses on the causes, symptoms, and repair costs of the P0715 code.

P0715 Definition

The P0715 code stands for malfunction in the transmission input/turbine speed sensor “A” circuit. 

What Does the P0715 Code Mean?

The P0715 code is triggered when the Transmission Control Module (TCM) or Powertrain Control Module (PCM) notices an erratic signal from the transmission input speed sensor.

This code is related to the communication between a car’s transmission and engine.

P0715 code

The input speed sensor is mounted on or in the vehicle transmission. This sensor is used to calculate the revolutions per minute (RPM) at which the transmission input shaft is rotating.

The input/turbine speed sensor is usually a 3-wire sensor that reads the gearbox reluctor ring. When the DTC P0715 is activated, your car can go into “fail-safe” mode. This is a situation where the speed and power of your car are restricted to minimize damage to other parts.

Your car’s PCM does this because it does not know the RPM of the transmission and cannot select a reliable gear to shift.

P0715 Code Symptoms

  • Illuminated Check Engine Light
  • Poor fuel efficiency
  • A reduction in engine performance
  • Car stuck in one gear
  • Your car goes in “Fail-Safe” mode
  • Improper working of the odometer/speedometer
  • Abnormal transmission operation
  • Shifting problems
  • Stalling when coming to a stop
  • The car is not moving

Read More: P0705 Code Symptoms and Causes

P0715 Code Causes

  • Damaged speed sensor electrical connection
  • Bad or damaged input speed sensor
  • Dirt on output speed sensor
  • Faulty reluctor ring for input speed sensor
  • Bad or damaged output speed sensor
  • Bad torque converter
  • Dirt on input speed sensor
  • Bad shift solenoid
  • Damaged transmission valve body
  • Faulty speed sensor wiring
  • Low transmission fluid

Read More: Exhaust Leak Symptoms and Causes

How to Diagnose the P0715 Code

You must have the below given basic tools to fix or diagnose the P0715 code:

  • A system wiring diagram
  • Vehicle specific service manual
  • Multimeter
  • A suitable diagnostic scanner, a digital volt/ohmmeter (DVOM)
  • Basic hand tools

Follow the following steps to diagnose the trouble code P0715:

  1. Properly check the input speed sensor to check its wiring condition.
  2. Attach the scanner to the diagnostic port and save the stored codes. Write down all of the saved code for future reference. If you have the freeze frame data, then also note it.
  3. If both an output sensor code and an input sensor code are present, utilize the scan tool data stream to find the faulty circuit. Reduce data stream to comprise only relevant data for faster data transfer.
  4. After eliminating the sensor, inspect the magnet contacts for excessive metal debris. Before reinstalling the sensor, remove additional dust. After removing the sensor, check the breakaway slot or reluctance wheel slot.
  5. Using DVOM, test each sensor according to the manufacturer’s specifications (see service manual or all data).
  6. Change the sensors that do not meet specifications. Please remove the associated controllers before using DVOM to test continuity and resistance. If you do not remove controllers, then your controllers may damage during this testing process.
  7. Replace or repair defective circuits.
  8. Test the system circuits for shorts.
  9. If all system circuits and sensors are normal, suspect a PCM failure or PCM programming error.

Common P0715 Code Diagnostic mistakes

  1. Replacing the input speed sensor without inspecting for deposits or reluctor ring
  2. Changing the input speed sensor without inspecting the transmission oil level.
  3. Changing the turbine speed sensor without properly inspecting the input speed sensor wiring for damage.

How serious is the P0715 code?

The P0715 code affects the vehicle in different ways, with some codes causing no apparent problem while others result in the transmission not shifting at all. An automatic transmission that doesn’t shift is not only uncomfortable; it’s also dangerous.

P0715 Code Repair Cost

For the P0715 code, you may need one or more of the below repairs to fix the original problem. For each possible repair, the estimated cost includes the cost of the relevant parts and the labor required to make the repair.

PartCost
Input speed sensor replacement$90 to $310
Torque converter replacement$610 to $1600
Transmission replacement$1700 to $4600
Wiring repair/replacement$90 to $1100
Output speed sensor replacement$90 to $310

Frequently Asked Questions

Can I drive a car with the P0715 code?

A P0715 trouble code denotes a severe problem. Therefore, you shouldn’t drive your car with P0715. This code can put your car into a fail-safe mode, resulting in severe gear changes, and the car may not accelerate at all. Your car may not be drivable when this code.

What is an input speed sensor?

The input/turbine speed sensor calculates the speed of the input shaft. This speed is taken from the upper countershaft drive gear. The main shaft speed sensor calculates the transmission gearing speed that comes out of the main housing and is taken off the upper auxiliary countershaft gear.

What repairs can fix the P0715 code?

  • Replacing the shift solenoid
  • Replacing the input/turbine speed sensor
  • Add more transmission fluid if needed 
  • Repairing damaged wiring for the input speed sensor
  • Removing the dirt from the input speed sensor
  • Replacing the output speed sensor
  • Replacing the torque converter
  • Repairing or replacing the PCM 

What does the transmission speed sensor do?

A speed sensor senses a specific gear or wheel in the transmission and produces an electronic digital signal that is equal to the speed of rotation. The transmission controller uses this data to improve the functionality of different transmission parts, such as shift points, and to perform diagnostic tests.

Is a speed sensor easy to replace?

Yes, it is easy to replace a wheel speed sensor and takes you about an hour at maximum. You can also remove the ABS wheel speed sensors separately, keeping other parts integrated into the wheel bearing hub assembly.

What causes a vehicle input speed sensor to malfunction?

Failure to follow your vehicle’s maintenance schedule can increase the risk of speed sensor failure. The speed sensor will not give an accurate reading if the magnet pickup or gears are heavily covered with mud, especially dirt from the old transmission fluid.

Can I drive with a broken input speed sensor?

In general, you shouldn’t drive your car with a damaged or broken input speed sensor because driving is unsafe. Your vehicle’s PCM can’t determine your vehicle’s speed, so it may slow you down or increase your car engine power more than usual.

Read More
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