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Harley Davidson Throttle Position Sensor Problems: Tips and More

Chase Manhattan Avatar

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Harley Davidson motorcycles are known for their power and performance, but even the most well-built machines can experience problems. One common issue that Harley riders face is related to the throttle position sensor (TPS). The TPS is a crucial component of the motorcycle’s fuel injection system, monitoring the throttle position and relaying that information to the engine control module (ECM). When the TPS malfunctions, it can cause a range of problems that affect the bike’s performance and drivability.

Some of the most common symptoms of Harley Davidson throttle position sensor problems include low speed, stiff throttle, hesitation or stalling, surging at certain throttle points, and a drop in gas mileage. In some cases, a failed TPS can even lead to engine failure. Riders who experience any of these issues should have their TPS inspected and repaired as soon as possible to avoid further damage to the bike.

Fortunately, there are several ways to diagnose and fix Harley Davidson throttle position sensor problems. Riders can check for wiring issues, inspect the TPS for damage or corrosion, and perform a TPS reset to recalibrate the sensor. In some cases, replacing the TPS may be necessary to fully resolve the issue. By understanding the symptoms and causes of TPS problems, Harley riders can take proactive steps to keep their bikes running smoothly and avoid costly repairs down the line.


Functionality of TPS

Throttle Position Sensor (TPS) is an essential component of a motorcycle’s fuel injection system. It monitors the position of the throttle and relays that information to the engine control module (ECM). The TPS is responsible for regulating the amount of air and fuel mixture that enters the engine, based on the rider’s throttle input. The TPS sends a signal to the ECM, which then adjusts the fuel injection and ignition timing accordingly.

The TPS works by using a potentiometer, which is a variable resistor that measures the voltage output based on the position of the throttle. The TPS is typically located on the throttle body or carburetor and is connected to the throttle shaft. When the rider twists the throttle, the TPS sends a signal to the ECM, which then adjusts the fuel and air mixture to provide the desired acceleration.

TPS in Harley-Davidson Motorcycles

Harley-Davidson motorcycles are equipped with electronic throttle control, which means that the TPS is responsible for regulating the amount of air and fuel mixture that enters the engine. The TPS is a critical component of the motorcycle’s engine management system and can cause various problems if it malfunctions.

One of the common problems with the TPS in Harley-Davidson motorcycles is a lack of power, hesitation, stalling, or even engine failure. These problems can arise due to various reasons, including wear and tear, damage, or incorrect adjustment. In some cases, the TPS may become dirty or contaminated, leading to inaccurate readings and improper fuel injection.

In conclusion, the Throttle Position Sensor is an essential component of a motorcycle’s fuel injection system, and it plays a critical role in regulating the amount of air and fuel mixture that enters the engine. Harley-Davidson motorcycles are equipped with electronic throttle control, which means that the TPS is responsible for regulating the engine’s performance. Understanding the TPS and its functionality is crucial for maintaining the motorcycle’s optimal performance.

When the throttle position sensor (TPS) in a Harley Davidson motorcycle starts to fail, it can cause a variety of symptoms that can be frustrating and potentially dangerous. Here are some of the most common symptoms of TPS issues:

Stalling and Hesitation

One of the most noticeable symptoms of a failing TPS is stalling and hesitation. This can happen at idle or when accelerating. The engine may also stall when coming to a stop. When the TPS fails, it can cause the engine to receive incorrect information about the throttle position, which can lead to stalling and hesitation.

Poor Engine Performance

Another symptom of TPS issues is poor engine performance. The engine may have limited performance, with reduced power and acceleration. The engine may also run rough and have poor fuel economy. When the TPS fails, it can cause the engine to receive incorrect information about the throttle position, which can lead to poor engine performance.

Check Engine Light Indicators

When the TPS fails, it can cause the check engine light to come on. This is because the engine control module (ECM) is receiving incorrect information from the TPS. The ECM uses the information from the TPS to control the fuel injection system, so when the TPS fails, it can cause a variety of engine problems that trigger the check engine light.

If you are experiencing any of these symptoms, it is important to have your Harley Davidson motorcycle inspected by a qualified mechanic. They can diagnose the problem and replace the TPS if necessary.

Diagnosing TPS Problems

When a Harley Davidson motorcycle is experiencing issues with the throttle position sensor (TPS), it can cause a number of problems with the fuel injection system, resulting in rough idling, engine misfires, and unusual or excessive exhaust emissions. Here are some methods to diagnose TPS problems:

Using a Multimeter

One way to diagnose TPS problems is to use a multimeter to measure the voltage output of the sensor. To do this, turn the ignition switch to on, connect the voltmeter across pin 30 (+) and pin 16 (grnd), and gradually open the throttle. The voltage should increase steadily with no spikes or low voltages. Observed voltages should be from 0.2 – 0.4 at idle, to 4.6 – 4.95 at wide open throttle.

Error Codes and ECM Diagnostics

Another way to diagnose TPS problems is to use an engine control module (ECM) diagnostic tool to check for error codes. The ECM monitors the TPS and other sensors for proper operation and will store error codes if a problem is detected. These error codes can be read using a diagnostic tool, such as a Harley Davidson Digital Technician II (DT II) or a Harley Davidson Diagnostic Scan Tool (DST).

If an error code is detected, the diagnostic tool can provide information on the specific problem with the TPS, such as a faulty sensor or wiring issue. The diagnostic tool can also be used to reset the TPS and clear any error codes that may be present.

In conclusion, diagnosing TPS problems on a Harley Davidson motorcycle can be done using a multimeter or an ECM diagnostic tool. By measuring the voltage output of the sensor or checking for error codes with a diagnostic tool, riders can identify and fix TPS problems before they cause serious issues with the fuel injection system.

Replacing a Faulty TPS

If the throttle position sensor (TPS) in your Harley Davidson is faulty, it will need to be replaced. This is a fairly straightforward task that can be completed by a qualified technician or an experienced DIYer. Here are the steps to follow:

  1. Obtain a replacement TPS that is compatible with your Harley Davidson model. You can find this information in your service manual or by consulting with a reputable Harley Davidson dealer.
  2. Locate the TPS on your motorcycle. It is usually located on or near the throttle body.
  3. Disconnect the wiring harness from the TPS. This may require the use of a small screwdriver or pliers to release the clip.
  4. Remove the mounting screws that hold the TPS in place. These screws may be located on the top or bottom of the TPS, depending on your model.
  5. Carefully remove the old TPS from the throttle body. Be sure to keep track of any gaskets or seals that may need to be replaced.
  6. Install the new TPS in the same location as the old one. Use the mounting screws to secure it in place.
  7. Reconnect the wiring harness to the new TPS. Be sure to double-check that the clip is securely in place.

How To Reset The Throttle Position Sensor On A Harley Davidson

Once you have replaced the TPS, you will need to calibrate and reset it. This is important to ensure that your motorcycle is running smoothly and efficiently. Here are the steps to follow:

  1. Turn off your motorcycle and remove the key from the ignition.
  2. Locate the TPS on your motorcycle. It is usually located on or near the throttle body.
  3. Loosen the mounting screws that hold the TPS in place. This will allow you to adjust the position of the TPS.
  4. Use a multimeter to check the voltage output of the TPS. This will help you determine the correct position for the TPS.
  5. Adjust the position of the TPS until the voltage output is within the correct range. This range can be found in your service manual or by consulting with a reputable Harley Davidson dealer.
  6. Tighten the mounting screws to secure the TPS in place.
  7. Turn on your motorcycle and let it idle for a few minutes. This will allow the TPS to adjust to the new position.
  8. Test ride your motorcycle to ensure that it is running smoothly and efficiently.

By following these repair and replacement procedures, you can ensure that your Harley Davidson throttle position sensor is working properly. If you are unsure about any of these steps, it is always best to consult with a qualified technician or a reputable Harley Davidson dealer.

Tips For Preventive Measures and Regular Maintenance

Regular maintenance is essential to ensure that the throttle position sensor (TPS) of a Harley Davidson motorcycle functions properly. The TPS 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 power and poor fuel economy. In this section, we will discuss the importance of regular checks and professional mechanic inspections to prevent TPS problems.

Importance of Regular Checks

Regular checks can help identify potential issues with the TPS before they become major problems. Harley Davidson recommends that owners perform regular maintenance on their motorcycles, including checking the TPS, as outlined in the service manual. The service manual provides detailed instructions on how to check the TPS, including how to measure the resistance of the sensor and how to adjust it if necessary.

In addition to following the service manual, owners should also pay attention to any changes in the performance of their motorcycle. If the motorcycle experiences any of the symptoms associated with TPS problems, such as sudden loss of power while accelerating or delayed throttle response, owners should have the TPS checked immediately.


What are the common symptoms indicating a failing throttle position sensor on a motorcycle?

A failing throttle position sensor (TPS) can cause a variety of symptoms on a motorcycle, including unstable idle, hesitation or stumbling during acceleration, poor fuel economy, and even stalling. In some cases, the engine may not start at all. These symptoms can be caused by a malfunctioning TPS that is not accurately measuring the position of the throttle.

How can you reset the throttle position sensor on a Harley Davidson bike?

To reset the throttle position sensor on a Harley Davidson bike, you first need to locate the sensor, which is usually located on or near the throttle body. On some models, the TPS may be integrated into the throttle body itself. Before attempting a reset, inspect the wiring and connections of the TPS for any signs of damage or corrosion. Ensure all connections are secure. Once you have checked the wiring and connections, you can reset the TPS by disconnecting the battery for a few minutes. Reconnect the battery and start the engine. The TPS should now be reset.

What steps should be taken to diagnose throttle position sensor issues on a Harley Davidson?

To diagnose throttle position sensor issues on a Harley Davidson, you should first check for any error codes using a diagnostic tool. If there are no error codes, you can test the TPS using a multimeter. With the ignition on and the engine off, connect the multimeter to the TPS and check the voltage. The voltage should increase smoothly as you open the throttle. If the voltage does not increase smoothly or does not change at all, the TPS may be faulty.

Are there any specific year models of Harley Davidson known for throttle position sensor failures?

Throttle position sensor failures can occur on any year model of Harley Davidson. However, some models may be more prone to TPS issues than others. It is important to follow the manufacturer’s recommended maintenance schedule and to address any issues as soon as they arise to prevent further damage.

What is the process for replacing a throttle position sensor on a Harley Davidson?

The process for replacing a throttle position sensor on a Harley Davidson can vary depending on the model. In general, the TPS is located on or near the throttle body and can be removed by unscrewing the mounting screws. Before replacing the TPS, inspect the wiring and connections for any signs of damage or corrosion. Ensure all connections are secure. Once you have installed the new TPS, reset it using the steps outlined above.

How does a malfunctioning throttle position sensor affect the performance of a Harley Davidson?

A malfunctioning throttle position sensor can cause a variety of performance issues on a Harley Davidson, including unstable idle, hesitation or stumbling during acceleration, poor fuel economy, and even stalling. In some cases, the engine may not start at all. It is important to address any TPS issues as soon as they arise to prevent further damage to the engine and to ensure safe operation of the motorcycle.