If you own a Harley-Davidson motorcycle, you may have encountered trouble codes at some point. These codes are generated by the motorcycle’s onboard diagnostic system (OBD) when it detects one or more malfunction sensors, circuits, or components. One of the most common codes that Harley riders experience is code 81406, which indicates an invalid or missing EQ in the audio system.
When you see code 81406 on your Harley, it means that there is an issue with the equalizer (EQ) in your audio system. The EQ is responsible for adjusting the balance and tone of your music, and if it is not working properly, you may experience poor sound quality or no sound at all. This can be frustrating, especially if you enjoy listening to music while you ride.
Fortunately, there are ways to address this issue and get your audio system back up and running. In this article, we will explore what code 81406 means, what causes it, and how to fix it. Whether you are a seasoned Harley rider or a new owner, this guide will provide you with the information you need to troubleshoot and resolve this common issue.
Understanding Harley Code 81406
If you are a Harley-Davidson owner, you may have come across the DTC code 81406. This code is related to the audio system of your motorcycle and can cause some issues if left unaddressed. In this section, we will explain what this code means and what symptoms you may experience.
Significance of Code 81406
Code 81406 is an audio system DTC code that indicates an invalid or missing EQ. EQ stands for equalizer, which is a device that adjusts the balance between different frequencies in an audio signal. In simpler terms, the equalizer helps you adjust the bass, treble, and other sound settings to your liking.
When the ECM (Engine Control Module) detects an issue with the equalizer, it will trigger the 81406 code and turn on the check engine light. This code can be caused by a variety of issues, such as a loose connection, a faulty amplifier, or a damaged speaker.
Common Symptoms
If you see the 81406 code on your Harley-Davidson, you may experience the following symptoms:
- No sound from the audio system
- Poor sound quality
- Inability to adjust the equalizer settings
- Check engine light is on
If you experience any of these symptoms, it is recommended to take your motorcycle to a certified Harley-Davidson mechanic for diagnosis and repair. They will be able to use diagnostic tools to pinpoint the exact cause of the issue and provide a solution.
In conclusion, the 81406 code is related to the equalizer in your Harley-Davidson’s audio system. If you experience any symptoms related to this code, it is important to get it diagnosed and repaired by a professional mechanic.
Diagnostic Trouble Codes (DTCs) Explained
If you own a Harley-Davidson, you might have come across Diagnostic Trouble Codes (DTCs) at some point. DTCs are codes that are stored in your motorcycle’s onboard diagnostic system. They can help you identify issues with your bike and are essential for troubleshooting and repair. In this section, we’ll explain what DTCs are and how to read them.
Reading DTCs
To read DTCs on your Harley-Davidson, you need a diagnostic tool like the Digital Technician II (DTII) or the Harley-Davidson Smart Security System (H-DSSS). These tools can access your motorcycle’s onboard diagnostic system and retrieve the codes. Once you have the codes, you can use a Harley-Davidson Fault Code Chart to identify the issue.
DTCs and Harley Models
Different Harley-Davidson models have different DTCs. For example, the Harley-Davidson Touring models have DTCs like B1103, B1153, B1200, B2102, B2103, B2104, B2112, B2113, and B2114. These codes correspond to different issues with the bike’s sensors, circuits, or components.
It’s important to note that DTCs are not always accurate and can sometimes be triggered by a faulty sensor or wiring issue. Therefore, it’s essential to diagnose the issue accurately before attempting any repairs. If you’re not sure how to read or diagnose DTCs, it’s best to take your bike to a qualified Harley-Davidson technician.
In conclusion, DTCs are an essential tool for troubleshooting and repairing your Harley-Davidson. Reading and diagnosing DTCs can be challenging, but with the right tools and knowledge, you can identify and fix issues with your bike.
Electrical System Insights
Harley-Davidson motorcycles are known for their powerful engines, iconic style, and advanced electrical systems. However, even the most advanced electrical systems can experience issues from time to time. In this section, we’ll explore some common electrical system insights related to Harley code 81406.
Battery and Charging System
The battery and charging system are critical components of your Harley-Davidson motorcycle’s electrical system. If your battery is not charging properly, it can lead to a variety of issues, including poor performance, reduced fuel efficiency, and even stalling. To ensure that your battery and charging system are working properly, it’s important to perform regular maintenance and inspections.
One of the most common causes of battery and charging system issues is a faulty alternator. If your alternator is not working properly, it may not be able to provide enough power to keep your battery charged. Additionally, a faulty regulator can cause your battery to overcharge, which can lead to damage and reduced battery life.
ABS and Sensor Malfunctions
Another common electrical system issue that can cause Harley code 81406 is ABS and sensor malfunctions. The ABS system is designed to help prevent wheel lockup and skidding, which can be especially dangerous in wet or slippery conditions. However, if your ABS system is not working properly, it can lead to reduced braking performance and increased stopping distances.
One of the most common causes of ABS and sensor malfunctions is a faulty wheel speed sensor. If your wheel speed sensor is not working properly, it may not be able to accurately detect the speed of your wheels, which can cause your ABS system to malfunction. Additionally, a faulty ABS pump or motor can cause your ABS system to fail, which can lead to reduced braking performance and increased stopping distances.
In summary, if you’re experiencing Harley code 81406, it’s important to perform a thorough inspection of your battery, charging system, ABS system, and sensors. By identifying and addressing any issues early on, you can help ensure that your motorcycle is safe, reliable, and ready to ride.
Fuel Injection and Engine Management
If you encounter trouble with your Harley, the onboard diagnostic system will generate fault codes that can help identify the issue. One such code is 81406, which indicates an invalid or missing EQ in the audio system. In this section, we will discuss the fuel injection (FI) and engine management system of your Harley-Davidson motorcycle.
FI System Components
The FI system consists of various components that work together to ensure proper fuel delivery and engine performance. These components include the electronic control unit (ECU), engine coolant temperature (ECT) sensor, intake air temperature (IAT) sensor, throttle position sensor (TPS), manifold absolute pressure (TMAP) sensor, crankshaft position (CKP) sensor, heated oxygen sensor (HO2S), and twist grip sensor (TGS).
ECU Functions and Errors
The ECU is the brain of the FI system and is responsible for monitoring and adjusting various engine parameters. It receives input from the sensors and uses this data to determine the correct fuel delivery and ignition timing. If the ECU detects an issue with any of the sensors or components, it will generate a fault code.
Harley-Davidson motorcycles have a comprehensive onboard diagnostic system that can help identify issues with the FI system. If you encounter a fault code, consult your owner’s manual or take your motorcycle to a certified Harley-Davidson technician for diagnosis and repair.
In conclusion, the FI system and engine management system of your Harley-Davidson motorcycle are complex systems that require careful maintenance and attention to ensure proper performance. By understanding the various components and functions of these systems, you can better diagnose and repair any issues that may arise.
Handling System Errors
If you own a Harley Davidson, you may encounter system errors that can be frustrating to deal with. One of the error codes that you might come across is code 81406. This code is related to an EQ correlation error in the audio system. In this section, we will discuss how to handle system errors in general and specifically when dealing with LHCM and RHCM issues, as well as throttle and speed controls.
LHCM and RHCM Issues
LHCM and RHCM are acronyms for the Left and Right Hand Control Modules respectively. These modules are responsible for controlling various functions on your Harley, such as the turn signals, horn, and high beam. If you encounter an internal error with either the LHCM or RHCM, you may notice that certain functions are not working correctly.
If you have an LHCM internal error, you may experience issues with the up, center, or down buttons. These buttons may become stuck, making it difficult to use the turn signals or other functions. Similarly, if you have an RHCM internal error, you may experience issues with the info, up, or center buttons.
To resolve LHCM or RHCM issues, you may need to replace the faulty module. This can be done by a qualified technician at your local Harley Davidson dealership.
Throttle and Speed Controls
Another area where you may encounter system errors is with the throttle and speed controls. If you have a problem with the speedometer or VSS (Vehicle Speed Sensor), you may notice that your speedometer is not working correctly. This can be dangerous as it can make it difficult to know how fast you are going.
If you encounter a problem with the throttle, you may notice that your Harley is not accelerating as it should. This can be caused by a faulty throttle sensor or other issues with the throttle control.
To resolve throttle and speed control issues, you should take your Harley to a qualified technician. They will be able to diagnose the problem and recommend the appropriate solution.
In conclusion, system errors can be frustrating to deal with, but they can be resolved with the help of a qualified technician. If you encounter an error code like 81406, don’t panic. Instead, take your Harley to a dealership and let a professional handle the issue.
Audio and Accessory Circuit Issues
If you are experiencing issues with your Harley Davidson’s audio and accessory circuits, it can be frustrating. These issues can be caused by a variety of factors, including faulty speakers, switches, and overloaded accessory circuits. In this section, we will discuss some of the most common issues that can arise in these circuits and how to troubleshoot them.
Speaker and Switch Faults
If you notice that your front or rear left or right speaker is open, it could be due to a faulty connection or a blown speaker. To troubleshoot this issue, you can check the connections to the speakers and replace any that are damaged. You can also use a multimeter to test the resistance of the speakers and ensure that they are functioning correctly.
Another common issue with audio circuits is a faulty switch. If you notice that your audio system is not turning on or off properly, it could be due to a faulty switch. You can test the switch using a multimeter and replace it if necessary.
Accessory Circuit Overloads
If your accessory circuit is overloaded, it can cause issues with the operation of your Harley Davidson. This can be caused by a short circuit or an overloaded circuit. To troubleshoot this issue, you can use a multimeter to test the resistance of the circuit and ensure that it is functioning correctly.
If you notice that your accessory output is overloaded, you can try disconnecting some of the accessories to reduce the load on the circuit. You can also check the wiring of the circuit to ensure that it is not damaged or corroded.
In conclusion, audio and accessory circuit issues can be frustrating, but they can usually be resolved with some troubleshooting and basic knowledge of the circuits. By following the steps outlined in this section, you can diagnose and fix these issues and get back to enjoying your Harley Davidson.
Preventive Measures and Maintenance Tips
When it comes to Harley Code 81406, there are some preventive measures and maintenance tips you can take to ensure that your motorcycle is running smoothly. Here are some tips to help you avoid encountering this code and keep your Harley in top condition.
Regular Check-Ups
Regular check-ups are essential to keep your Harley in good condition. You should have your motorcycle checked by a professional mechanic at least once a year, or more frequently if you ride it frequently. During these check-ups, the mechanic will inspect your motorcycle’s vital components, including the throttle position sensor, and make any necessary repairs or replacements.
Upkeep of Critical Components
The upkeep of critical components is crucial to the health of your motorcycle. The throttle position sensor is a critical component of the fuel injection system, and any issues with it can lead to a range of problems, from rough idling and stalling to reduced fuel efficiency. Regular maintenance is essential to ensure that the throttle position sensor of your Harley Davidson motorcycle functions properly.
You should also regularly check your motorcycle’s VIN to ensure that it is up-to-date and accurate. The VIN is a unique identifier assigned to your motorcycle, and it contains information about the vehicle’s make, model, and year. Keeping your VIN up-to-date is essential for maintaining the vehicle’s health and ensuring that it is running optimally.
In addition to regular check-ups and upkeep of critical components, there are other maintenance tips you can follow to keep your motorcycle in top condition. These include:
- Checking your fuel level sender regularly for any signs of wear or damage, and replace it if needed.
- Keeping your motorcycle clean and free of debris, which can cause damage to critical components.
- Following the manufacturer’s recommended maintenance schedule, which includes regular oil changes, tire rotations, and other maintenance tasks.
By following these preventive measures and maintenance tips, you can avoid encountering Harley Code 81406 and keep your Harley Davidson motorcycle running smoothly for years to come.
Advanced Troubleshooting Techniques
When it comes to Harley codes, sometimes the standard troubleshooting techniques just won’t cut it. In these cases, it’s time to break out some advanced techniques to get to the root of the problem. Here are some techniques you can try when dealing with Harley code 81406:
Check the CAN bus: The Controller Area Network (CAN) bus is responsible for communication between different modules in your Harley, such as the Engine Control Module (ECM), Body Control Module (BCM), and Instrumentation Control Module (ICM). If there’s an issue with the CAN bus, it can cause a variety of codes to appear, including 81406. Check the wiring and connections in the CAN bus to ensure everything is working properly.
Test the ECM: The ECM is the brain of your Harley, responsible for controlling the fuel injection, ignition timing, and other essential functions. If there’s an issue with the ECM, it can cause code 81406 to appear. Use a diagnostic tool to test the ECM and ensure it’s functioning properly.
Check the radio: The radio in your Harley can also cause code 81406 to appear. If there’s an issue with the radio, it can cause a high voltage signal to be sent to the ECM, triggering the code. Check the wiring and connections in the radio system to ensure everything is working properly.
Inspect the ACC and ACR: The Accelerator Control Circuit (ACC) and Accelerator Control Relay (ACR) are responsible for ensuring the throttle operates correctly. If there’s an issue with either of these components, it can cause code 81406 to appear. Inspect both the ACC and ACR to ensure they’re functioning properly.
Check the BAS: The Bank Angle Sensor (BAS) is responsible for detecting when your Harley is leaning too far to one side. If there’s an issue with the BAS, it can cause code 81406 to appear. Check the wiring and connections in the BAS to ensure everything is working properly.
Inspect the LHCM: The Left Hand Control Module (LHCM) is responsible for controlling the turn signals, horn, and other functions on the left side of your Harley. If there’s an issue with the LHCM, it can cause code 81406 to appear. Inspect the LHCM to ensure it’s functioning properly.
Check the fuel signal: Code 81406 can also be caused by a high fuel signal. This can happen if there’s an issue with the fuel pump or fuel injector. Check the fuel system to ensure everything is working properly.
By using these advanced troubleshooting techniques, you can get to the root of the problem causing code 81406 on your Harley. Remember to always follow proper safety procedures when working on your motorcycle, and if you’re unsure about anything, consult a professional mechanic.