P0718 – Input/Turbine Speed Sensor Circuit Intermittent

The P0718 trouble code indicates an intermittent issue with the input/turbine speed sensor circuit. This code is commonly found in vehicles equipped with OBD-II systems from various manufacturers. The powertrain control module (PCM) detects an irregular voltage input signal from the input speed sensor, which is responsible for monitoring the transmission’s input speed in RPM. The input speed sensor is typically located near the bell housing, at the transmission input shaft. It uses a notched reluctor wheel or grooves on the transmission main shaft to complete an electronic circuit with the sensor. If the input/turbine speed or system circuit voltage deviates from the predetermined degree of accuracy, the P0718 code is triggered. Common symptoms include erratic speedometer operation, improper shifting of the transmission, and reduced fuel efficiency. Possible causes of this issue include a defective input speed sensor, damaged wiring or connectors, PCM failure, or metal debris on the magnetic sensor.

Key Takeaways:

• The P0718 trouble code indicates an intermittent issue with the input/turbine speed sensor circuit.
• It is commonly found in vehicles equipped with OBD-II systems.
• Common symptoms include erratic speedometer operation, improper shifting of the transmission, and reduced fuel efficiency.
• Possible causes include a defective input speed sensor, damaged wiring or connectors, PCM failure, or metal debris on the sensor.
• It is important to have the issue diagnosed and repaired by a professional to ensure proper vehicle operation.

Symptoms of OBD Code P0718

The symptoms associated with OBD Code P0718 can vary from vehicle to vehicle. However, there are some common signs that indicate the presence of this error code. If you experience any of these symptoms, it is advisable to have your vehicle diagnosed by a professional technician to identify the underlying cause.

1. Erratic Speedometer Operation: One of the primary symptoms of OBD Code P0718 is an erratic speedometer (odometer) operation. You may notice fluctuations or inaccuracies in the speed reading displayed on your dashboard.
2. Improper Shifting of the Transmission: Another symptom is the improper shifting of the transmission. Your vehicle may exhibit difficulties in changing gears smoothly, resulting in jerky or delayed shifts.
3. Speedometer and/or Odometer Failure: In some cases, the P0718 error code can lead to a complete failure of the speedometer and/or odometer. This means that these vital instruments may stop functioning altogether.
4. Erratic or Harsh Transmission Shift Points: If your vehicle experiences inconsistent or abrupt transmission shift points, it could indicate the presence of the P0718 error code. You may notice the transmission shifting too early or too late, causing a disruption in your driving experience.
5. Decreased Fuel Efficiency: Alongside the above symptoms, some drivers may observe a decrease in fuel efficiency. This can manifest as increased fuel consumption, resulting in more frequent visits to the gas station.

Remember, these symptoms can vary depending on the specific make and model of your vehicle. Consulting a qualified technician is crucial to accurately diagnose and address the issue related to OBD Code P0718.

Common Causes of P0718 Error Code

The P0718 error code can be triggered by several common causes. It is essential to identify and address these underlying issues to prevent further damage and ensure the proper operation of your vehicle.

Defective Input Speed Sensor

A defective input speed sensor is a frequent culprit behind the P0718 error code. This sensor is responsible for monitoring the transmission’s input speed in RPM. If it becomes faulty, it can send irregular voltage input signals to the powertrain control module (PCM).

Wiring and Connector Issues

Damaged, loose, or burnt wiring and connectors can also contribute to the P0718 error code. Faulty connections or compromised wiring can disrupt the transmission of accurate speed data, leading to the code being triggered.

Faulty Powertrain Control Module (PCM)

If the powertrain control module (PCM), which regulates and controls various engine and transmission functions, is faulty, it may not receive or interpret the input speed sensor signals correctly. This can result in the P0718 error code being logged.

Programming Error in the PCM

In some cases, a programming error in the PCM can cause the P0718 error code to appear. This can occur during manufacturing or when software updates are not properly installed. The incorrect programming can lead to inaccurate readings from the input speed sensor.

Accumulation of Metal Debris

The presence of metal debris on the magnetic sensor can disrupt the function of the input speed sensor and trigger the P0718 error code. These debris particles can interfere with the sensor’s ability to accurately detect the speed of the transmission, leading to the code being logged.

If you encounter the P0718 error code, it is recommended to consult a professional mechanic or technician. They have the expertise and diagnostic tools to identify the specific cause of the error code and perform the necessary repairs or replacements.

How to Correct P0718 Input/Turbine Speed Sensor A Circuit Intermittent

To correct the occurrence of the P0718 error code, there are several steps that can be taken:

1. Replace the input speed sensor: If the input speed sensor is found to be faulty or damaged, it is recommended to replace it. The input speed sensor is responsible for monitoring the transmission’s input speed in RPM, and a malfunctioning sensor can trigger the P0718 error code.
2. Repair or fix broken wires and circuits: Check for any broken or damaged wires and connectors related to the input/turbine speed sensor circuit. If any issues are found, repair or replace the damaged components to ensure proper signal transmission.
3. Address power control module or programming errors: Sometimes, the P0718 code can be caused by issues with the power control module (PCM) or programming errors. It is recommended to consult a professional or follow the manufacturer’s guidelines to address any PCM-related issues effectively.

By following these steps and addressing the potential causes of the P0718 error code, you can correct the input/turbine speed sensor circuit intermittent issue and restore proper operation to your vehicle.

Quote:

“Addressing the underlying causes of the P0718 error code is crucial to prevent further damage and ensure the optimal performance of your vehicle.” – [Author Name]

Conclusion

In conclusion, the P0718 error code indicates an intermittent issue with the input/turbine speed sensor circuit. This code can manifest in various symptoms, including erratic speedometer operation and improper shifting of the transmission. To diagnose and resolve this issue, proper vehicle diagnostics, including transmission diagnostics, are crucial.

A defective input speed sensor, damaged wiring or connectors, PCM failure, or metal debris on the sensor are common causes of the P0718 error code. Troubleshooting the speed sensor and addressing the underlying problem is essential to ensure the proper functioning of the vehicle.

If you encounter the P0718 error code, it is recommended to seek professional vehicle diagnostics to accurately identify and rectify the issue. A qualified technician will be able to perform thorough transmission diagnostics and speed sensor troubleshooting to pinpoint the exact cause of the problem. Prompt action will not only prevent further damage but also optimize the vehicle’s performance and fuel efficiency.