If you own a Harley-Davidson motorcycle and have encountered the P2138 error code, you may be wondering what it means and how to fix it. This error code typically indicates a problem with the throttle position sensor (TPS) or the throttle body itself. The TPS is responsible for sending signals to the engine control module (ECM) to regulate the throttle position, which affects the amount of air and fuel that enters the engine.
When the TPS or throttle body malfunctions, the ECM may not receive accurate signals, resulting in the P2138 error code. This can cause a number of issues with your motorcycle’s performance, including reduced power, poor acceleration, and even stalling. It’s important to address this issue as soon as possible to prevent further damage to your motorcycle and ensure your safety on the road.
Fortunately, there are a few steps you can take to diagnose and fix the P2138 error code. These may include checking the wiring connections to the TPS, cleaning the throttle body, or replacing the TPS altogether. It’s important to consult your owner’s manual or a qualified mechanic for guidance on how to properly address this issue.
Understanding Code P2138
If you own a Harley Davidson motorcycle, you may have come across the code P2138. This code is related to the throttle position sensor and can cause your bike to go into limp mode or reduced power mode. In this section, we will discuss the symptoms of P2138 and the causes behind it.
Symptoms of P2138
The most common symptom of P2138 is the check engine light (CEL) coming on. This can be accompanied by the bike going into limp mode or reduced power mode. You may also experience stalling or a lack of power when accelerating.
Causes Behind P2138
There are several causes behind P2138, including:
- A faulty throttle position sensor (TPS)
- A damaged or corroded TPS wiring harness
- A problem with the electronic control module (ECM)
- A loose or damaged connector in the TPS circuit
If you suspect that your bike is experiencing P2138, it is important to have it diagnosed by a qualified technician. They will be able to determine the root cause of the problem and provide the necessary repairs.
In conclusion, P2138 is a common code that can cause your Harley Davidson to go into limp mode or reduced power mode. By understanding the symptoms and causes behind this code, you can take the necessary steps to keep your bike running smoothly.
Throttle and Sensor Basics
If you’re experiencing issues with code P2138 on your Harley Davidson motorcycle, it’s important to understand the basics of the throttle and sensor systems. The throttle system is responsible for regulating the amount of air and fuel that enters the engine, while the sensor system helps to monitor and adjust the throttle as needed.
Throttle Position Sensor (TPS)
The Throttle Position Sensor (TPS) is a critical component of the throttle system. It measures the position of the throttle plate and sends that information to the Engine Control Module (ECM). The ECM then uses that information to adjust the fuel and air mixture to the engine. If the TPS is not functioning properly, the ECM may not be able to adjust the fuel and air mixture correctly, resulting in poor engine performance and the P2138 code.
Twist Grip Sensor (TGS)
The Twist Grip Sensor (TGS) is another important component of the throttle system. It measures the position of the twist grip on the handlebars and sends that information to the ECM. The ECM uses this information to adjust the throttle position as needed. If the TGS is not functioning properly, the ECM may not be able to adjust the throttle position correctly, resulting in poor engine performance and the P2138 code.
It’s important to note that the TPS and TGS work together to ensure that the throttle system is functioning properly. If one of these sensors is not working correctly, it can cause issues with the other sensor and the overall performance of the throttle system.
In addition to the TPS and TGS, there is also a Throttle/Pedal Position Sensor/Switch (TPS) that is responsible for determining how much the driver is pressing on the gas pedal. This sensor is most commonly found in vehicles with electronic throttle control systems.
Overall, understanding the basics of the throttle and sensor systems can help you diagnose and fix issues with code P2138 on your Harley Davidson motorcycle. By ensuring that the TPS and TGS are functioning properly, you can help to ensure that your motorcycle is running smoothly and efficiently.
Electrical System Inspection
When your Harley-Davidson motorcycle is throwing the P2138 code, it can be frustrating. However, with a little bit of knowledge and some basic tools, you can diagnose and fix the issue. Here are some steps you can take to inspect your electrical system and hopefully find the source of the problem.
Wiring and Connectors
The first thing you should check when you encounter the P2138 code is your wiring and connectors. Make sure all of your connectors are clean and free of corrosion. Pinched wires can cause issues, so check for any areas where your wiring may be pinched or damaged. If you find any issues, repair or replace the affected components as needed.
Voltage and Circuit Checks
Next, you should perform some voltage and circuit checks. Using a multimeter, check the voltage at the throttle position sensor (TPS) and the twist grip sensor (TGS). Make sure the voltage readings are within the manufacturer’s specifications. If the voltage readings are not within the specified range, you may need to replace the affected sensor.
You should also check the circuits between the TPS and TGS. Make sure the circuits are not shorted or open. If you find any issues with the circuits, repair or replace the affected components as needed.
Applying dielectric grease to your connectors can also help prevent issues with corrosion and improve the longevity of your electrical system. Make sure to use the appropriate type of dielectric grease for your connectors.
By following these steps, you can inspect your electrical system and hopefully find the source of the P2138 code. Remember to always refer to your Harley-Davidson service manual for specific instructions and specifications.
Diagnostic Procedures
If you are experiencing Harley code P2138, there are a few diagnostic procedures you can try to determine the root cause of the issue. Here are two methods you can use:
Using a Scan Tool
One of the first things you can do is to use a scan tool to diagnose the problem. Start by connecting the scan tool to your bike’s OBD-II port. Once connected, use the tool to read the trouble codes. If you see P2138, this means there is a problem with the throttle position sensors. The scan tool can also be used to read data and determine which sensor is causing the issue.
Manual Testing
Another method to diagnose the problem is to test the sensors manually. Start by disconnecting the throttle position sensor connector. Then, using a multimeter, check the resistance between the pins on the sensor. The resistance should be within the range specified in your bike’s service manual. If the resistance is not within the specified range, the sensor may need to be replaced.
You can also test the wiring between the sensor and the ECM. Check for continuity between the sensor connector and the ECM connector. If there is a break in the wiring, this could be causing the issue.
By using these diagnostic procedures, you can troubleshoot and diagnose the problem with your Harley code P2138.
Repair and Replacement
If you have diagnosed the P2138 code as a problem with the Throttle Pedal Position Sensor and Throttle Grip Sensor, you will need to replace them. It’s important to note that you should not attempt to repair the sensors themselves, as they are not serviceable components.
Replacing TPS and TGS
To replace the Throttle Pedal Position Sensor and Throttle Grip Sensor, you will need to remove the throttle body from the engine. This is a delicate procedure, so it’s important to follow the manufacturer’s instructions carefully. Once you have removed the throttle body, you can remove the old sensors and install the new ones.
Before you install the new sensors, make sure that the connectors are clean and free of debris. You can use a contact cleaner to remove any dirt or corrosion that may have accumulated on the connectors. Once the connectors are clean, you can install the new sensors and reassemble the throttle body.
Connector and Wiring Repair
If you have determined that the problem is with the wiring or connectors, you will need to repair or replace them. Start by inspecting the connectors for damage or corrosion. If the connectors are damaged, you will need to replace them.
To repair damaged wiring, you will need to cut out the damaged section and splice in a new section of wire. It’s important to use the correct gauge wire and to make sure that the connections are secure. You can use a soldering iron or crimp connectors to make the connections.
If you are not comfortable with repairing wiring or connectors, it’s best to take your motorcycle to a qualified mechanic. They will have the expertise and tools necessary to diagnose and repair the problem.
Additional Considerations
Handlebar and Accessory Impact
If you have recently swapped your handlebars or installed any accessories, it is possible that the wiring or connections have been impacted. This can lead to the P2138 code being triggered. Make sure to check all wiring and connections for damage or looseness. Additionally, if you have installed heated grips, make sure that they are properly installed and wired.
ECM and Cruise Control
The P2138 code can also be triggered by issues with the ECM or cruise control system. If you suspect that this may be the case, it is important to have your motorcycle diagnosed by a qualified technician. They will be able to determine if there are any issues with the ECM or cruise control system, and make the necessary repairs.
It is important to note that the P2138 code can also be accompanied by other codes such as TGS2 low/open, TGS correlation error, and P2127. If you are experiencing any of these codes in addition to P2138, it may be an indication of a more serious issue. In this case, it is highly recommended that you seek the assistance of a qualified technician.
Overall, it is important to take the P2138 code seriously and address it promptly. Ignoring the code can lead to further damage to your motorcycle and potentially dangerous riding conditions. By following the steps outlined in this article and seeking the assistance of a qualified technician when necessary, you can ensure that your motorcycle is running at its best.
Harley Community Insights
When it comes to Harley Davidson motorcycles, there is a vibrant community of riders who are always willing to help each other out. If you are experiencing code P2138, you can turn to this community for advice and support. Here are some insights from the Harley community that can help you understand this code and how to deal with it.
Forums and Expert Advice
One of the best places to turn for advice on Harley codes is the online forums. There are several forums dedicated to Harley Davidson motorcycles where you can find expert advice on everything from air cleaners to engine control modules. Some popular forums include Harley Davidson Forums, V-Twin Forum, and Harley Riders USA.
If you are experiencing code P2138, you can post a question on one of these forums and get advice from other riders who have experienced the same issue. You can also search the forums for previous posts on this code to see what others have done to fix it.
Common Modifications and Effects
Many Harley riders like to modify their bikes to improve performance or customize their look. While these modifications can be fun and exciting, they can also have unintended effects on your bike’s performance. For example, if you have installed an aftermarket air cleaner or exhaust system, this can affect the air/fuel ratio and cause code P2138 to appear.
If you are experiencing this code, it is important to consider any modifications you have made to your bike and how they might be affecting its performance. You should also check the accelerator pedal position sensor and gas pedal to make sure they are functioning properly.
If you are in limited performance mode or experiencing reduced engine power, it is important to address this issue as soon as possible. Ignoring this code can lead to further damage to your bike and potentially dangerous situations on the road.