What Does The Red Key Light Mean On A Harley? In-Depth Overview

Red is widely accepted as something negative or stopping from doing anything. It may also mean there is possibly a danger happening soon. Similarly, most motorcycles, including Harley Davison (HD), have a red key light that flashes on the odometer. If it turns on, you should immediately stop riding the bike while turning it off. 

So, what does the red key light mean on a Harley?  In short, it is chiefly an indicator of Harley’s internal security system. It warns the rider whether the security system is compromised or not. If your motorcycle has any security issues, the light will remain stable.

So, it is essential to inspect faster why the light is on after turning off the vehicle.  Please, continue reading the post to learn why and how the red key light works in HD bikes. 

What Does The Red Key Light Mean On A Harley

What Does The Red Key Light Mean On A Harley? – You Should Know

What Does The Red Key Light Mean On A Harley - You Should Know

The red light key on Harley refers to the internal security of their motorbikes. If there’s any security compromise or unauthorized access to your Harley Davidson bike, the light will alert you. At this time, you need to inspect the security system and take necessary action. 

However, you must understand the working pattern of the red light and why it remains on to operate it properly. In the next sections, we will answer these queries. 

The Working Pattern of Harley Red Key Light

You may know it has a Check Engine Light (CEL) if you own a car. It performs as an invigilator that identifies any Diagnostic Trouble Code (DTC) that the Turn Signal (TSM or TSSM) or Security module sets. Hence, the red key light of Harley works with the same purpose. 

Usually, this light goes off when you turn on the engine of the HD bike. It refers to the disabling of the security system of the two-wheeler. But things will not remain the same if you see the light is on even after turning on the bike. This stable lighting means the bike has thrown a DTC. 

Why the Red Key Light Remains on After Turning the Bike Engine On?

Why the Red Key Light Remains on After Turning the Bike Engine On?

The main reason is any DTC in your Harley bike, indicated through the red key light. In general, it happens due to the error code in the TSSM of the bike. You should read the user manual and inspect the problem to fix any security system’s ECM code if it happens. 

Some other reasons for red key light remaining stable can be a faulty key, dead battery, defective control module, electrical interference, and broken signal wires. 

The Way Harley Davidson Security System Performs 

The Way Harley Davidson Security System Performs 

The security system works in two ways: arming and disarming the system under different conditions. 

Arming the Security System

When you park the motorbike in the parking lot after turning off the ignition switch, the Security System starts working automatically. It takes a maximum of 5 seconds to turn on. Once the system is on, the turn signals and an alarm (optional) will peep. Besides, you will see the key icon of the speedometer flashing after every 3 seconds while remaining armed. 

Disarming the Security System

The system deactivates when you turn on the ignition key to the IGNITION position if any fob is assigned. While the security system module is disarmed, you will hear the chirping of the optional siren. Also, you will experience the illumination of the key indicator for 4 seconds before it goes off. 

Activation of an HD Security System 

The system starts working when you turn off the ignition switch. If there is no motion nearby the parked bike, the system arms will turn on within 5 seconds. Once the arming activates, the siren I mentioned earlier will beep two times. Also, there will be a two-timing flash of turn signals. You can deactivate the system using the key fob after triggering it. 

Troubleshooting The Faults Of Harley Security System

Troubleshooting The Faults Of Harley Security System

The red key light is on after you turn on and move the Harley bike. Now, you understand there is a problem with the security system. What will you do to troubleshoot the security system in this situation?

Well, nothing to worry about as I am explaining the way to troubleshoot and maintain the health of the security system:

Bring The Battery Out

You can detach the battery by lifting the compartment top. After that, you should use an electronic cleaner spray to keep the area neat and clean. The spray duration can be 4-5 seconds. Then, install a new pair of batteries instead of the old ones. Lastly, cover the lid of the compartment to finish the job. 

Inspect The Sensor Module Of The Alarm 

Inspect The Sensor Module Of The Alarm 

You should arrange a spirit level module on the bike seat’s part. Then, ensure the bubbles remain in the two drawn lines’ midpoint and start moving the sensor module. If you want to reattach it to the hooking pad, you should press the module down. It will cling to it in the wire tracing. Finally, set the back end of the seat in the correct position. 

Tracing Of Wire

Usually, the placement of the sensor module is under the driving seat. Use a locking clamp to maintain the order of the loose wires while reaching the alarm system. The alarm system has its place close to the handlebars. If you want to make it strong or secure, you should use a flat spatula. Sometimes, a flat-edged screwdriver will do the job. Wire tracing is a repetitive job on the alarm sign. 

Why Do Harley Davidson Lights Flash?

Why do Harley Davidson Lights Flash

Suppose your very own Harley bike has a high-quality security system. Then, you will hear the alarm that the motion sensors trigger if you move near the bike. The flashing lights usually drain the battery after riding the bike for around 600 miles. 


The security of your Harley Davidson motorbike is always top-notch as the manufacturer is always ready to serve you the best riding experience. The red key light is an integral part of this security system. But the DTC enables the key light to turn on unnecessarily. 

If you have read the whole post, I hope you understand the meaning of the red key light. Also, you can troubleshoot the possible problems from now.

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