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The check engine light on your Harley Davidson is part of the onboard diagnostic system, which monitors critical engine components such as sensors, wiring, and components that impact your motorcycle’s overall performance.
When a problem is detected, the light activates, and the corresponding trouble code is stored in the bike’s ECM.
Tools Needed to Check Engine Codes on Harley Davidson
You could find these two car scan tools on Ancel.
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OBD2 Scanner: For most modern Harley Davidson models, you will need an OBD2 scanner to access the ECM. Make sure to choose one that is compatible with Harley Davidson motorcycles.
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Diagnostic Bluetooth Scanner: Wireless Bluetooth OBD2 readers are also available, allowing you to check the engine codes from your smartphone or tablet.
Related Reading: Enhance Your Motorcycle Troubleshooting with the Ancel MT700 Motorcycle Code Reader
Check Engine Codes on Harley Davidson
Step 1: Locate the OBD2 Port
The OBD2 port on a Harley Davidson is typically located near the bike’s seat or under the left side of the dashboard. For some models, you may need to remove a panel to access the port. On certain Harley models, the port may be found beneath the left side panel, below the headlamp, or near the gas tank.
Step 2: Connect the OBD2 Scanner
Once the OBD2 port is located, connect your OBD2 scanner or Bluetooth OBD2 reader to the port. If you're using a Bluetooth scanner, make sure your device is paired with your smartphone or tablet and that you have the appropriate app installed.
Step 3: Turn the Key to the "On" Position
With the motorcycle scanner connected, turn the key to the “on” position (don’t start the engine yet). This will activate the ECM and allow the scanner to access the diagnostic data stored in the system.
Step 4: Read the Engine Codes
Using your scan tool, initiate a scan to retrieve the engine codes stored in the ECM. Depending on your scanner, you may need to follow specific prompts to begin the scan. The scanner will display the trouble codes, which can often be in the form of a combination of letters and numbers (e.g., P0301).
Step 5: Interpret the Engine Codes
Each Harley Davidson engine code corresponds to a specific problem or malfunction. Common engine codes on Harley Davidson bikes include:
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P0300-P0304: These codes refer to issues with misfires, often indicating a problem with the ignition system or fuel injectors.
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P0400-P0499: These codes are related to the exhaust system, including issues with the EGR valve or oxygen sensors.
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P0500-P0599: These codes usually point to problems with vehicle speed sensors or electrical components.
Step 6: Clear the Codes (If Necessary)
After addressing the engine issue, you can clear the trouble codes from the system. Most OBD2 scanners allow you to erase the stored codes, resetting the check engine light. It’s important to fix the underlying problem before clearing the codes to ensure the issue doesn’t recur.
Common Engine Code Issues on Harley Davidson Motorcycles
1. Fuel System Problems
Fuel system malfunctions, such as a clogged fuel injector or fuel pressure issues, can lead to engine misfires or poor performance. This often triggers codes related to the fuel system or ignition system.
2. Sensor Failures
A malfunctioning oxygen sensor or MAP sensor (Manifold Absolute Pressure sensor) can lead to inaccurate data being sent to the ECM, causing engine performance issues and triggering codes.
3. Electrical Issues
Loose or corroded wires, faulty connectors, or battery issues can cause voltage problems that the ECM will flag with codes. Always inspect the electrical components and wiring before diving into more complex repairs.
4. Exhaust Gas Recirculation (EGR) Problems
The EGR valve controls the recirculation of exhaust gases to reduce emissions. When it fails, it can cause poor engine performance and trigger specific codes related to emissions.
5. Ignition System Failures
Spark plug or ignition coil issues are common causes of engine misfires and can trigger codes related to the ignition system. Checking and replacing faulty ignition components can resolve these issues.
ANCEL Ultimate Motorcycle Diagnostic Tool You Need!
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The ANCEL MT700 harley davidson scan tool could be the solution you need.
Need to reset your oil lamp or perform a throttle valve adaptation?
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FAQs
Can I check engine codes on older Harley Davidson models?
Yes, older Harley Davidson models may not have an OBD2 port. However, many can still be diagnosed using aftermarket tools or through dealer-specific equipment, which may require more specialized knowledge and devices for code reading.
What should I do if the OBD2 scanner shows a code I don’t understand?
If you're unsure about a code, it's always best to consult the owner's manual or seek help from a professional mechanic. You can also research the specific code online, as many diagnostic tools will provide detailed descriptions of the issues associated with the code.
Can I reset the engine light myself after fixing the issue?
Yes, most OBD2 scanners allow you to clear the engine codes and reset the check engine light once you've addressed the issue. Simply use the scanner to reset the system, and the light should go off if no further issues are detected.
