The P0715 code is a diagnostic trouble code that indicates a malfunction in the circuit responsible for the transmission input or turbine speed sensor “A.” When the input speed sensor fails, the PCM (Powertrain Control Module) triggers this code. This code is a sign that there is a problem with the sensor that measures the speed of the input shaft in the transmission. The P0715 code can cause various symptoms, such as transmission shifting issues, engine stalling, or even complete failure of the transmission. To correct the issue, the faulty sensor must be replaced and the circuit checked for any additional damage.
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What Is P0715 Code?
The code P0715 is an error code that is related to the communication between the engine and transmission in a vehicle. The input/turbine speed sensor, located within the transmission, measures the speed of the input shaft and sends this information to the Powertrain Control Module (PCM). If the PCM receives an irregular signal from this sensor, it triggers the P0715 code.
This error code is important because the input/turbine speed sensor plays a crucial role in the vehicle’s transmission system. The sensor helps the PCM to determine the speed of the transmission so that it can properly select the correct gear for the vehicle to operate in. If the PCM receives an incorrect signal, it may cause the vehicle to shift gears unexpectedly or not shift gears at all.
When the P0715 code is triggered, the vehicle will most likely go into “fail-safe” mode. This is a safety feature that limits the vehicle’s power and speed to prevent damage to other components. This is because the PCM is not able to accurately determine the speed of the transmission, and without this information, it cannot safely switch gears.
P0715 code is a warning that there is an issue with the communication between the engine and transmission in a vehicle. It is important to address this issue promptly to prevent further damage to the transmission and other components.
Causes
- Input Speed Sensor Failure: The input speed sensor can fail due to damage, wear and tear, or exposure to environmental elements like dirt and debris. This can lead to a P0715 code and result in incorrect information being transmitted to the vehicle’s engine control module (ECM).
- Reluctor Ring Damage: The reluctor ring is a toothed wheel that rotates along with the transmission’s input shaft. If the reluctor ring is damaged, it can cause incorrect readings to be taken by the input speed sensor, resulting in a P0715 code.
- Speed Sensor Wiring Issues: Wiring issues can also cause a P0715 code. This may include damaged or frayed wires, loose or corroded electrical connections, or incorrect wiring.
- Output Speed Sensor Malfunction: The output speed sensor is responsible for monitoring the speed of the transmission’s output shaft. If this sensor fails or becomes damaged, it can result in a P0715 code.
- Electrical Connection Problems: Damaged or loose electrical connections can cause a P0715 code. This can result in incorrect readings being taken by the speed sensors or a loss of power to the transmission control module.
- Dirty Input Speed Sensor: Dirt and debris can collect on the input speed sensor and interfere with its ability to take accurate readings. This can result in a P0715 code.
- Shift Solenoid Failure: The shift solenoid is responsible for controlling the shifting of gears in the transmission. If the shift solenoid fails, it can result in a P0715 code.
- Valve Body Damage: The transmission valve body is responsible for directing fluid to the appropriate clutches and bands in the transmission. If the valve body becomes damaged, it can result in a P0715 code.
- Torque Converter Issues: The torque converter is responsible for transmitting engine power to the transmission. If the torque converter fails or becomes damaged, it can result in a P0715 code.
- Transmission Fluid Problems: Low or contaminated transmission fluid can cause a P0715 code. This can result in incorrect pressure readings being taken by the speed sensors or a loss of power to the transmission control module.
- Dirty Output Speed Sensor: Dirt and debris can also collect on the output speed sensor and interfere with its ability to take accurate readings. This can result in a P0715 code.
Symptoms
P0715 is a diagnostic trouble code (DTC) that indicates an issue with the Input Speed Sensor circuit. The following are symptoms associated with this code:
- Check Engine Light illumination – The check engine light in the dashboard of your vehicle may turn on, indicating that there is a problem with the engine or transmission system.
- Poor fuel efficiency – The vehicle may consume more fuel than usual due to the malfunctioning input speed sensor circuit.
- Your car goes in “Fail-Safe” mode – In some vehicles, the transmission system may go into a “Fail-Safe” mode when the input speed sensor circuit is malfunctioning. This mode limits the vehicle’s speed and performance.
- Inappropriate operation of the speedometer/odometer – The speedometer and odometer readings may be incorrect, or may not work at all.
- Shifting issues – The transmission may have difficulty shifting gears, or may not shift at all.
- Abnormal transmission operation – The transmission may exhibit unusual behaviors such as slipping, harsh shifting, or not engaging.
- Stalling when coming to a stop – The engine may stall when the vehicle comes to a stop, due to the input speed sensor circuit not providing the proper information to the engine control module.
- The vehicle is not moving – The vehicle may not move at all, or may only move in a limited manner.
- Poor engine performance – The engine may not run smoothly, or may have reduced power and acceleration.
- No noticeable adverse conditions in some cases – In some cases, there may not be any noticeable symptoms, but the Check Engine Light may still be illuminated.
- Vehicle stuck in one gear – The transmission may become stuck in one gear, and will not shift to another gear.
How To Fix P0715 Code
Here are the step by step procedure to fix P0715 code.
- Visually inspect the input/turbine speed sensor to check its condition and the condition of its wiring.
- Connect the scanner to the diagnostic port and retrieve all stored codes. Make a note of all stored codes for future reference. You should also note freeze frame data, if available.
- If both input sensor and output sensor codes are present, use the scanner data stream to determine which circuit is malfunctioning. Narrow the data stream to include only related data for more responsive data delivery.
- When removing sensors, check for excessive metal debris on magnetic contacts. Remove excessive debris before reinstallation. Inspect interruption grooves and reluctor wheel notches when sensors are removed.
- Test individual sensors using the DVOM and following the manufacturer’s specifications (found in the service manual or through All Data).
- Replace sensors that fail to comply with specs. Disconnect related controllers before testing resistance and continuity with the DVOM. Failure to do so could cause controller damage.
- Test system circuits for shorted or open wiring.
- Repair or replace defective circuits.
- If all system circuits and sensors are in proper working order, suspect a faulty PCM or a PCM programming error.