How to Check Harley Error Codes

How to Check Harley Error Codes

by Chris Rutter November 19, 2020

When your Harley isn't running right or a light on the dashboard flares up, you need to check out your Harley-Davidson diagnostic codes. These codes reveal where there may be a malfunction in different parts of your Harley and let you know what needs repairing. Keeping your bike in optimal condition starts with understanding how to check error codes and making a habit of doing so regularly to catch issues early.

To keep your Harley running at top condition and recognize times when parts of your bike need repair, you'll want to know how to check your Harley for its diagnostic codes. This guide can give you a hand.

Steps for Checking Harley-Davidson Diagnostic Codes

When your Harley seems off or you want to give it a quick check, you can access your bike's diagnostic trouble codes (DTCs). You can take a few simple steps to view the codes and see if anything is malfunctioning. Any biker can check these DTCs on their own, as the process is fairly simple.

Accessing your bike's diagnostic trouble codes (DTCs)

Learn more about how to check Harley codes below:

  1. Turn the ignition off: Ensure your ignition switch is flipped to the off position. Next, set your Run/Stop button to Run.
  2. Hold down the odometer reset button: Locate the odometer reset button, which should be on your bike's dash. If you can't find it, consult your owner's manual to find out where it is. If you have a 2014 model or older, the odometer will be on the left control mount and come in the form of a toggle switch. Once you've located the odometer reset button, hold it down.
  3. Release the button: Release the odometer reset button after you've switched the ignition switch to its Ignition position. Once you've released the odometer button, the indicator lamps should light up, the background should illuminate and the speedometer needle should cycle through its entire range, sweeping all the way. "Diag" text should also show up on the odometer. 
  4. Press the odometer button again: After you've seen the proper areas light up and the needle go through its full sweep, you can press the odometer reset button again. Instead of holding it down, just press the reset button one time. After you press this button, a menu should appear with the text "PSSPt." The initial P in PSSPt will be flashing. 
  5. Scan through the diagnostic modules: The letters in PSSPt refer to different parts of the diagnostics module. You can tell which part of the diagnostic module you're currently checking by looking at which letter is flashing. To move between letters, all you have to do is press the odometer reset button down once to go to the next letter. These letters are referred to as modules.
  6. Identify what each module means: To move forward in checking the diagnostic codes, you should know what each letter of PSSPt refers to. The P stands for the Electronic Control Module (ECM) and the Ignition Control Module (ICM). The first S refers to the Turn Signal (TSM) and the Turn Signal Security Module (TSSM). The SP stands for the bike's speedometer, and the lowercase T refers to the tachometer. If your bike doesn't have a tachometer, you'll see "No RSP" when you select the tachometer identifier module.
  7. Hold down the odometer button again: To check out the DTCs related to each of these modules, hold down the odometer button for five seconds before releasing it. If the word "none" appears on the screen, your diagnostics aren't picking up any issues. For times when the diagnostics have identified something is wrong, a DTC will appear. Keep pressing the odometer reset button to see any additional codes you may need to address.
  8. Record any DTCs: Record any codes you see so you can look them up to learn what they mean and what could be wrong.
  9. Display the module's part number: After cycling through any of the DTCs, you can push down on the odometer reset button and then release it. The module's part number will then be displayed.
  10. Distinguish between historic and current codes: For times when you want to clear the displayed code to see if it's historic or current, press and hold the odometer reset button for over five seconds until "clear" shows up. Once the "clear" text appears, release the reset button and turn off your bike's ignition switch. Next, fire up your bike again and then turn it off to recheck the DTCs, following the previous steps to do so. A historic code won't reappear, but a current code will.
  11. Check any other DTCs: To check the modules for other DTCs, push down on the odometer reset button and release it to move on.
  12. Switch the ignition off: Once you're done checking for DTCs, switch your ignition off to end the Harley code checking process. 

Understanding DTC Codes

You can identify the Harley diagnostic codes by checking whether they have a U, P, C or B designation. A "U" code signals modules that have a communication problem. A "P" code will let you know the issue likely comes from a component monitored by the ECM. A "C" code tells you there's an Anti-Lock Braking System issue. Finally, a "B" code indicates an issue with the Body Control Module, instruments and radio.

 How to find out what the codes mean

Depending on your Harley's model year, you may have different diagnostic codes. You can find out what these codes mean by looking them up in your owners' manual or searching for them online.

What to Do If You See a DTC?

If your bike shows a DTC code that's not historic, you don't want to let it go unresolved. While some handy bikers may be able to fix some codes themselves, it's often best to bring the bike to a professional for repairs.

After you see a code, the first thing you should do is get the issue fixed. Once the repair is finished, whether it's conducted by a professional or yourself, ensure you restore all connections. With connections restored, clear the DTCs off the bike. Start your Harley and go through several diagnostic code cycles to see if the code returns. If it does, you may need to conduct further repairs.

Contact Fat Head Cycles for Help With Maintenance Codes

At Fat Head Cycles, we know all things Harley and can help you fix any diagnostic codes you've identified. Our experienced Harley motorcycle specialists are proud to serve customers with various maintenance, repair and custom motorcycle services. For those looking to make repairs on their bike themselves, we have a full online store with tons of parts, kits and modifications to take your Harley to the next level. 

If you need assistance addressing the codes and repairing your bike, our in-shop services are here to help. Contact us today to speak with one of our representatives about any questions you may have about our services or products.

Contact Fat Head Cycles for help with maintenance codes.

Chris Rutter
Chris Rutter


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