There can be various reasons why the engine light on a Harley-Davidson motorcycle may come on and off intermittently. The engine light, often referred to as the malfunction indicator lamp (MIL) or check engine light, is part of the onboard diagnostic (OBD) system and is designed to alert the rider of potential issues with the motorcycle's engine or emissions system.
Here are a few possible reasons why the engine light may illuminate intermittently:
Loose or faulty gas cap: A loose or faulty gas cap can cause the engine light to come on. This is a common issue and usually a simple fix. Ensure that the gas cap is properly tightened and functioning correctly.
Sensor issues: The engine light can be triggered by various sensors throughout the motorcycle's engine and emissions system. If a sensor is malfunctioning or providing intermittent readings, it can cause the engine light to illuminate and then turn off when the issue resolves temporarily. Examples of sensors include the oxygen sensor, throttle position sensor, or engine temperature sensor.
Emission system issues: Problems within the motorcycle's emission control system, such as a faulty catalytic converter or a malfunctioning exhaust gas recirculation (EGR) valve, can trigger the engine light to come on. If the issue is intermittent, the light may turn off when the system operates within normal parameters temporarily.
Wiring or connection issues: Faulty or loose wiring connections, damaged wiring harnesses, or corrosion in electrical connections can disrupt the signals from various engine components. This can lead to intermittent illumination of the engine light.
Software or computer issues: In some cases, glitches or software errors within the motorcycle's engine control unit (ECU) or powertrain control module (PCM) can cause the engine light to turn on and off intermittently. Software updates or resetting the ECU/PCM may be required to address the issue.
It's important to note that the engine light should not be ignored, even if it turns off. If the engine light illuminates frequently or stays on continuously, it is advisable to have the motorcycle diagnosed by a qualified technician or Harley-Davidson dealer. They can use diagnostic tools to retrieve error codes stored in the ECU/PCM and perform further troubleshooting to identify the specific cause of the intermittent engine light.