If you’re experiencing the P0718 code, it’s crucial to address it promptly to maintain optimal vehicle performance. This code indicates an intermittent issue in the Input or Turbine Speed Sensor Circuit, which can lead to transmission problems. The first step is to perform a thorough diagnostic check to pinpoint the source of the problem.
Start by inspecting the wiring and connectors related to the speed sensor. Look for any signs of corrosion, fraying, or loose connections, as these can cause intermittent signals. Ensure that the sensor is securely mounted and functioning correctly. Testing the sensor’s resistance and voltage output can provide insight into its operational status.
If the sensor appears to be in good condition, consider checking the Transmission Control Module (TCM) for faults. Resetting the TCM may resolve temporary glitches. If the problem persists after these steps, it may be necessary to replace the sensor or consult a professional technician for a detailed analysis.
Understanding P0718 Diagnostic Trouble Code
P0718 indicates an issue with the input or turbine speed sensor circuit in a vehicle’s transmission system. This code arises when the Engine Control Module (ECM) detects an intermittent issue in signal output from the sensor, which can lead to erratic shifting and poor vehicle performance.
Common Symptoms
Owners may experience several symptoms including:
- Illuminated check engine light
- Slipping transmission
- Delayed or harsh shifting
- Reduced fuel efficiency
Troubleshooting Procedures
To diagnose the P0718 code, follow these steps:
- Inspect the wiring and connectors for the input/turbine speed sensor for damage or corrosion.
- Check the sensor resistance with a multimeter, ensuring it falls within the manufacturer’s specifications.
- Test the ECM for faults or software issues that might affect the sensor’s performance.
- Clear the trouble code and take the vehicle for a test drive to see if the code reappears.
Addressing the underlying issue promptly can prevent further damage to the transmission system and restore optimal vehicle operation.
Common Symptoms Associated with the P0718 Code
When the P0718 code triggers, drivers often notice specific issues affecting vehicle performance. Pay attention to these common symptoms:
1. Transmission Slipping
Transmission slipping occurs when the engine RPM increases without a corresponding increase in vehicle speed. This phenomenon often signals trouble with the input/turbine speed sensor, leading to erratic shifting behavior.
2. Erratic Shifting
Drivers may experience unusual shifting patterns. The transmission might shift harshly or unpredictably, resulting in a rough driving experience. This symptom indicates potential issues with sensor readings impacting the transmission control module’s decisions.
| Symptom | Description |
|---|---|
| Transmission Slipping | RPM increases without speed increase, suggesting sensor malfunction. |
| Erratic Shifting | Shifts occur unpredictably or harshly, affecting driving comfort. |
| Check Engine Light | The light activates, indicating a fault related to the input/turbine speed sensor. |
| Poor Acceleration | Acceleration may feel sluggish due to improper gear engagement. |
| Unusual Engine Behavior | Engine performance may degrade, especially under load. |
Address these symptoms promptly to avoid potential damage to the transmission system. Regular maintenance and prompt diagnostics are crucial for ensuring long-term reliability.
Possible Causes of the P0718 Code in Vehicles
Faulty input or turbine speed sensors often trigger the P0718 code. A malfunctioning sensor may provide inconsistent readings, leading to erratic behavior in the transmission.
Wiring issues, such as frayed or damaged wires within the sensor circuit, can also cause intermittent signals. Inspect the wiring harness for signs of wear and tear to ensure proper connectivity.
Corrosion at the connector terminals might create resistance, affecting sensor performance. Cleaning the connectors can improve electrical flow and sensor response.
Short circuits or open circuits in the sensor circuit are common culprits. Conduct thorough testing to identify any breaks in the circuit that might impact the sensor’s signal transmission.
Transmission fluid problems can also lead to this trouble code. Low fluid levels or dirty fluid may cause erratic sensor readings. Ensure that the transmission fluid is at the correct level and in good condition.
ECU software glitches can sometimes contribute to miscommunication with the sensor. Updating the engine control unit’s software may rectify the issue if other causes appear to be eliminated.
Other mechanical problems within the transmission system may indirectly affect the sensor’s readings. A comprehensive diagnostic can help pinpoint underlying transmission concerns that need addressing.
How to Retrieve the P0718 Code from an OBD-II Scanner
Connect your OBD-II scanner to the vehicle’s diagnostic port, usually located under the dashboard near the steering column. Ensure the ignition is in the “On” position but the engine is off. This allows the scanner to communicate with the vehicle’s computer.
Once the scanner is on, navigate through the menus to select the option for “Read Codes” or similar. The scanner will communicate with the vehicle’s computer and retrieve any stored trouble codes.
Look for the error code P0718 in the displayed list. This code specifically indicates issues with the Input/Turbine Speed Sensor circuit. Take note of any additional codes that appear, as they may provide further insights into related problems.
If your scanner has a “Freeze Frame” or “Data Stream” option, explore this feature. It captures the vehicle’s sensor readings at the time the code was triggered, which can help diagnose the issue more effectively.
After noting the code and any additional information, clear the codes using the scanner if your intention is to see if they reappear after driving. This step helps determine whether the issue is intermittent.
Regularly retrieving and clearing codes can aid in the ongoing maintenance of your vehicle. With the P0718 code, you can check connections, inspect the sensor and wiring, or perform further diagnostics based on the information gathered.
Intermittent vs. Permanent Issues Related to P0718
P0718, indicating an intermittent malfunction in the Input/Turbine Speed Sensor circuit, presents unique challenges. Here’s how to distinguish between intermittent and permanent issues:
- Intermittent Issues:
- These problems usually manifest sporadically, which can lead to hesitation during acceleration.
- Electronic contacts may experience momentary failures, causing temporary voltage drops.
- Inspect wiring harnesses for fraying or loose connections, as these can intermittently disrupt signals.
- Check for corrosion or dirt on sensor terminals; cleaning them might resolve the issue.
- Monitor temperature changes; components may fail in extreme conditions but operate normally once cooled.
- Permanent Issues:
- Permanent failures usually lead to a constant speed sensor malfunction, halting vehicle operation.
- Your vehicle may display constant error codes, with no resets possible until repairs are made.
- Inspect the speed sensor itself, as physical damage or wear may require replacement.
- Evaluate the vehicle’s control module; a faulty ECU might impair sensor functionality entirely.
- Wiring harnesses must be checked thoroughly; damage that isn’t temporary often leads to complete electrical failure.
Addressing intermittent issues often requires detailed diagnostics and observation over time, while permanent problems typically need immediate repairs or component replacements. Keep records of when symptoms occur to aid your mechanic in diagnosis.
Impact of P0718 on Vehicle Performance
The P0718 code indicates an intermittent issue with the input or turbine speed sensor circuit. This has direct consequences on vehicle performance, especially in automatic transmission systems.
Reduced Transmission Efficiency
An intermittent signal from the turbine speed sensor affects the transmission control module’s ability to optimize gear shifts. This may lead to:
- Delayed shifts between gears.
- Rough shifting leading to uncomfortable driving experiences.
- Increased engine RPMs, causing strain on the engine and associated components.
Fuel Economy and Emissions
When the transmission struggles to find the appropriate gear, fuel consumption rises significantly. An improperly functioning speed sensor can lead to:
- Decreased fuel efficiency due to erratic shifting.
- Higher emissions due to increased fuel usage, potentially failing emissions tests.
Addressing the P0718 code promptly can restore normal vehicle performance and mitigate further damage to the transmission system. Regular maintenance and sensor diagnostics can prevent these issues from developing into more severe problems.
Steps to Inspect the Input Speed Sensor
Begin the inspection by ensuring the vehicle is off and the keys are removed from the ignition for safety. Follow these steps to conduct a thorough check on the input speed sensor:
- Locate the input speed sensor. It is typically found near the transmission or at the back of the engine, depending on the vehicle model.
- Visually inspect the sensor and its wiring harness for any signs of damage, such as cracks, fraying, or corrosion.
- Disconnect the wiring harness from the sensor. Check for bent pins or debris in the connector that may hinder a proper connection.
- Use a multimeter to test the resistance of the sensor. Consult the vehicle’s service manual for the specific resistance range expected for your model.
- While still connected, start the engine and use the multimeter to measure the voltage output of the sensor. It should produce a voltage that varies as the engine speed changes.
- If the readings are outside the specified ranges, consider replacing the sensor. If the sensor appears faulty, further testing of the wiring may be needed.
- Reassemble the wiring harness securely. Ensure the connections are tight and free from dirt.
After inspection, clear any error codes using a diagnostic scanner to reset the system. Test drive the vehicle to ensure that the issue is resolved and observe if the check engine light reappears.
Testing Wiring and Connectors for the P0718 Code
Begin by visually inspecting the wiring and connectors associated with the input/turbine speed sensor. Look for signs of wear, damage, or corrosion that could interfere with signal transmission. Pay attention to frayed wires or loose connections.
Next, use a multimeter to check for continuity in the wiring. Disconnect the sensors and measure resistance. A reading below specifications indicates a short or break in the wire. Verify each connector pin for proper connection. Ensure that all pins are straight and free of debris.
After confirming continuity, check for proper voltage at the sensor connector with the ignition turned on. You should receive voltage readings according to the manufacturer’s specifications. If voltage is missing, trace the wiring back to the source to identify any breaks or shorts.
Also, examine the ground connection. A poor ground can cause intermittent issues that trigger the P0718 code. Measure voltage between the ground pin of the sensor and a known good ground; any significant voltage indicates a grounding problem.
Finally, reconnect the wiring and connectors securely before retesting the vehicle system. Clear the fault code and monitor for reoccurrence. If the code persists, further investigation into the sensor itself may be required.
Replacing a Faulty Input Speed Sensor
To replace a faulty input speed sensor, start by disconnecting the vehicle’s battery to ensure safety. Locate the sensor, typically positioned near the transmission or on the transmission housing. Use a socket wrench to remove any bolts securing the sensor in place.
Next, disconnect the electrical connector from the sensor. Inspect the wiring and connector for any signs of damage or corrosion. If they appear compromised, consider replacing them as well.
Installation Steps
Install the new input speed sensor by reversing the removal steps. Ensure the sensor is properly aligned and secured with bolts. Reconnect the electrical harness, making sure it clicks into place. Once everything is secured, reconnect the battery and start the vehicle.
Check for any warning lights on the dashboard. A diagnostic scan tool can confirm the sensor’s functionality and clear any related trouble codes.
Maintenance Tips
To enhance longevity, regularly inspect the sensor and wiring for wear and tear. Clean the area around the sensor to prevent debris accumulation, which can affect performance. Following these steps helps maintain optimal transmission function.
| Step | Action |
|---|---|
| 1 | Disconnect battery |
| 2 | Locate and remove the old sensor |
| 3 | Check and replace damaged connectors if necessary |
| 4 | Install the new sensor |
| 5 | Reconnect the battery |
| 6 | Check for warning lights and trouble codes |
How to Diagnose Transmission Control Module Issues
Start with checking for any trouble codes using an OBD-II scanner. Pay particular attention to codes like P0718, which indicates a possible issue with the Input/Turbine Speed Sensor Circuit. This could affect how the Transmission Control Module (TCM) manages shifting.
Perform a Visual Inspection
- Inspect the wiring harness connected to the TCM and related sensors for signs of damage or corrosion.
- Look for loose connections or signs of short circuits.
- Check for fluid leaks that may affect electrical components.
Test the Input/Turbine Speed Sensor
- Disconnect the sensor from the wiring harness.
- Use a multimeter to measure the resistance across the sensor terminals. Compare the readings to the manufacturer’s specifications.
- Reconnect the sensor and monitor its data using a scan tool while the vehicle is in motion.
If the readings are inconsistent or out of range, consider replacing the sensor. If the sensor tests fine, the next step is to inspect the performance of the TCM itself.
Monitor TCM Functionality
- Use the scan tool to observe live data from the TCM while driving. Look for irregularities in shift timings or RPMs.
- Evaluate the TCM’s response to throttle input. Any delays or erratic shifts can point to malfunction.
- Perform a TCM reset after addressing any issues to see if the problem persists.
If problems continue, a deeper analysis might involve checking the TCM ground and power supply circuits for reliability. Ensure that all connectors are secure and free from dirt or moisture. In some cases, software updates from the manufacturer may also resolve issues.
In complex situations, enlist a professional mechanic who can conduct advanced diagnostics and troubleshoot at the module level, ensuring all systems communicate effectively for optimal transmission performance.
Common Mistakes in Diagnosing P0718
One significant mistake is assuming the input/turbine speed sensor itself is always faulty. Before replacing it, test the wiring and connections leading to the sensor for wear or corrosion. A poor electrical connection can trigger the P0718 code without needing a part replacement.
Another common error is not checking for other trouble codes. P0718 can sometimes coincide with other transmission-related codes, helping to narrow down the issue. A comprehensive scan ensures you don’t overlook underlying problems.
Overlooking the transmission fluid condition is also a frequent error. Contaminated or low fluid can impact sensor performance and lead to erroneous readings. Regularly check fluid levels and quality as part of your diagnostic routine.
Failing to utilize a digital multimeter during tests can hinder accurate diagnoses. Measuring voltage and resistance in the sensor circuit provides critical insights into its functionality, helping to verify whether the sensor or wiring is at fault.
Relying solely on visual inspections can lead to missed issues. Perform continuity tests on the wiring harness to confirm that signals are transmitted properly. Hidden damage might not be visible, so electrical testing is crucial.
Lastly, jumping to conclusions about the control module can misdirect your troubleshooting efforts. While a faulty module can result in P0718, make sure it is the last component you consider replacing, as this can be a more complex and costly fix. Focus first on simpler, common issues before assuming module failure.
Understanding the Role of the Turbine Speed Sensor
The turbine speed sensor measures the rotational speed of the turbine within the transmission system. This data plays a critical role in optimizing vehicle performance, as it directly affects the transmission’s shifting points and engine load calculations. By relaying RPM data to the vehicle’s control unit, the sensor helps ensure smooth gear transitions and enhanced fuel efficiency.
How It Functions
The turbine speed sensor typically operates using either a Hall effect or magnetic induction method. It generates voltage signals based on the speed of the turbine, allowing the engine control module (ECM) to make real-time adjustments. This feedback is vital for maintaining optimal engine performance and preventing issues like slipping or overheating.
Common Issues and Diagnosis
Intermittent problems with the turbine speed sensor can trigger diagnostic trouble codes like P0718. Such issues may stem from wiring problems, sensor malfunction, or poor connections. Regular inspections of the sensor and its circuitry can help identify potential faults before they escalate. Utilize a multimeter to check voltage and continuity, ensuring reliable operation and accurate readings.
Resetting the Code After Repairs: How and When
To reset the P0718 code after repairing the input/turbine speed sensor circuit, use an OBD-II scanner. Connect the scanner to the vehicle’s diagnostic port. Navigate to the option for clearing or resetting fault codes. Confirm the action, and the scanner will erase the stored trouble codes, including P0718.
Perform the reset only after confirming that the repairs are complete and the issue has been addressed. Clear the code before conducting a test drive to ensure the transmission operates correctly. During the test drive, monitor the vehicle’s performance and watch for any recurrent issues.
Consider turning off the ignition for about 10 seconds after resetting the code. This action can help ensure that any temporary codes are also cleared from the system. After restarting the vehicle, double-check the scanner to verify that the P0718 code does not return.
If the code reappears after the reset, revisit the repairs made to ensure that all wiring connections, sensors, and components are functioning correctly. In some cases, additional tests for electrical continuity and voltage may be necessary.
Document all repairs and resets to keep an accurate history. This practice can be helpful for future diagnostics or maintenance checks. Regularly monitoring performance after repairs leads to a more reliable driving experience.
When to Seek Help for P0718 Code
Seek assistance immediately if you notice erratic transmission behavior, including slipping, harsh shifting, or unexpected shifts. These symptoms strongly suggest issues linked to the P0718 code, which indicates a problem with the Input/Turbine Speed Sensor Circuit.
If the check engine light appears or blinks, consult a mechanic promptly. Ignoring these alerts can lead to further damage, increasing repair costs. It’s wise to address the situation before it escalates.
Check for transmission fluid leaks. Low fluid levels can exacerbate the issues caused by a faulty Input/Turbine Speed Sensor. If fluid is low, recheck regularly to ensure it’s not leaking and seek professional help if you suspect a leak.
Analyze your vehicle’s performance. If you experience poor acceleration or decreased fuel efficiency, these can be related to the P0718 code and indicate a need for expert evaluation.
Consider your driving conditions. If you have been frequently driving in stop-and-go traffic or towing heavy loads, this could strain your transmission, worsening the scenario outlined by the P0718 code. It may be time to consult with a technician to inspect the transmission system thoroughly.
| Symptoms | Recommendation |
|---|---|
| Erratic transmission behavior | Consult a mechanic immediately. |
| Check engine light activated | Seek professional help without delay. |
| Low transmission fluid | Inspect for leaks; get help if needed. |
| Poor acceleration | Evaluate performance and schedule inspection. |
| Strained driving conditions | Consider a thorough inspection of transmission. |
Addressing these symptoms quickly can save time and money, ensuring your vehicle remains reliable. Don’t hesitate to reach out to a service professional for help with the P0718 code issues.
Preventative Measures to Avoid P0718 Issues
Regularly inspect and maintain transmission fluid levels. Low fluid can lead to sensor malfunction.
Keep the transmission system clean. Dirt and debris can cause sensor failure. Use appropriate transmission fluid and change it as recommended.
Check the wiring and connectors leading to the input/turbine speed sensor. Look for corrosion, fraying, or loose connections that could interrupt the circuit.
Monitor for any unusual sounds or sensations while driving. Early detection of transmission issues can prevent further damage.
Consider using high-quality replacement parts if repairs are needed. Inferior components may not perform reliably, leading to recurring issues.
- Implement periodic diagnostic scans to catch codes early.
- Stay informed about service intervals specific to your vehicle’s make and model.
- Engage a qualified mechanic for any transmission work to ensure proper installation and calibration.
Ensure your vehicle’s software is updated, as manufacturers may release updates that enhance sensor performance.
Pay attention to your vehicle’s warning lights. Addressing minor alerts promptly can prevent major problems down the line.
Cost of Repairs Related to the P0718 Code
The repair costs for the P0718 code vary significantly based on factors like the vehicle make and model, the location of the repair shop, and the extent of the issue. Generally, the total expense can range from $100 to $1,000. This range typically reflects the cost of both diagnostic services and necessary repairs or parts replacement.
Common Repair Scenarios
If the input/turbine speed sensor is faulty, replacing it usually costs between $150 and $400. Labor costs are often between $75 and $150 per hour, depending on the shop’s rates. Occasionally, the sensor malfunction is a symptom of a more significant issue, such as a failing transmission. In such cases, repairs could escalate significantly, anywhere from $500 to $2,500, including possible transmission rebuilding or replacement.
Cuts to Costs
To manage repair costs effectively, it is beneficial to have regular vehicle maintenance. Addressing minor issues early can prevent larger, more expensive repairs later. Seeking multiple quotes from repair shops will help identify competitive pricing, and using aftermarket parts can further reduce expenses. Keep in mind that diagnosing the problem accurately can save money in unnecessary repairs, enhancing reliability and performance in the long run.
Real-world Case Studies of P0718 Resolutions
A vehicle owner faced a P0718 code while driving a 2010 Honda Accord. The symptoms included erratic shifting and occasional loss of power. The technician inspected the Input/Turbine Speed Sensor and found it to be faulty. Replacing the sensor immediately resolved the issue, with no further codes appearing after a test drive.
In another case, a 2015 Ford F-150 revealed a P0718 after experiencing harsh shifting and stumbling during acceleration. Diagnostic testing showed intermittent voltage fluctuations from the sensor circuit. The technician traced the problem to a damaged wiring harness, which was repaired. Subsequent tests confirmed the circuit was stable, restoring normal function.
A 2007 Nissan Altima exhibited signs of slipping transmission paired with the P0718 code. The owner changed the transmission fluid as a first step, which improved performance slightly. However, the code persisted. Further investigation led to the discovery of a faulty connector at the speed sensor’s plug. After cleaning and securing the connection, the problem was resolved, and the transmission operated smoothly.
One more instance involved a 2012 Chrysler 300 presenting P0718 alongside a transmission that would occasionally go into limp mode. The technician utilized a multi-scan tool and identified a software glitch in the transmission control module (TCM). Updating the TCM software eliminated the error code and restored the correct sensor readings, allowing the vehicle to operate normally.
In a 2016 Chevrolet Malibu, intermittent signs of harsh shifting were linked to the P0718 code. The technician performed a complete inspection of the wiring and found corrosion in the connector. After cleaning the connector and applying dielectric grease, the transmission returned to normal operation without any further codes.
These cases illustrate that while the P0718 code can stem from various issues, timely diagnostics and a methodical approach to repairs frequently lead to successful resolutions. Regular maintenance and thorough inspections of wiring and connectors can prevent such problems in the future.
