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Our 3 Master Techs are well-prepared to serve our Vermont, New Hampshire and New York riders with Harley-Davidson trouble codes.  Harley-Davidson Diagnostic Trouble Codes (DTCs) and Fault Conditions

Retrieving Trouble Codes on Your Harley-Davidson Motorcycle

Odometer Self-Diagnostics

Diagnostic Mode

To enter diagnostic mode, press and hold the trip odometer trigger switch located on the left handlebar controls, while turning the IGN ON.

Note

The trip odometer trigger switch is located in the left-hand control module. The switch signal is sent to the speedometer over the CAN bus. If there is a problem with the CAN bus, the odometer self-diagnostic mode may not function.

1. Release the trip odometer trigger switch. "diag" will appear on the odometer display.
2. Press and release the trip odometer trigger switch. ECM will appear on the odometer display. It will have either a "Y" or an "N" after it, depending if there are any ECM codes or not.
3. Quickly press and release the trip odometer trigger switch to cycle through the modules. Modules include the BCM, SPDO, ABS, and RAD.
4. Once the desired module is displayed, press and hold the trip odometer trigger switch.
5. If any DTCs are stored in the module, the odometer will display the DTC. Quickly pressing and releasing the trip odometer trigger switch will cycle through stored DTCs.
6. When all DTCs have been cycled the odometer will display "end".
7. To clear all DTCs in that module press and hold the trip odometer trigger switch, while a DTC is displayed. If DTCs are not to be cleared, quickly press and release the trip odometer trigger switch. The part number of the module will be displayed.
8. Press and release the trip odometer trigger switch again to continue to the next module.
9. Make note of all DTCs. Clear all DTCs and operate the vehicle to verify that DTCs set and are current. Historic DTCs are not to be diagnosed unless the condition is reoccurring and intermittent.
10. Turn IGN OFF to exit diagnostic mode. If IGN is not turned off, the vehicle will exit diagnostics mode when the vehicle starts moving.

Harley Trouble Code Types

There are three types of DTCs: current, pending, and historic. The odometer self-diagnostics displays all codes and differentiates between current and historic with a letter designator.

• Odometer self-diagnostics will display both current and historic DTCs.
• Current DTCs reside in the memory of the ECM, BCM, instruments, radio, or ABS module (if equipped) until the DTC is resolved.
• A historic DTC can be cleared by use of odometer self-diagnostics or after a total of 40 error-free ignition cycles (start and run cycle) have elapsed.

Current DTCs are those that presently disrupt motorcycle operations and are set during the current ignition cycle. To determine whether current DTCs are present, clear the DTCs and operate the vehicle within the parameters for setting the DTC. See the appropriate diagnostic procedures for solutions.

Some DTCs require multiple occurrences or drive cycles to set. When these DTCs are first recognized but have not been repeated enough to be set as current DTCs, they are reported as pending DTCs.

If a particular problem happens to resolve itself, the active status problem is dropped and it becomes a historic DTC rather than a current DTC. DTCs will also lose their current status when the ignition is turned off. If the problem still exists when the ignition is turned on, the code will show as current.

Historic DTCs are stored for 40 ignition cycles to assist in the diagnosis of intermittent faults. On the 40th error-free cycle, the DTC will clear itself.

It is important to note that historic DTCs will exist whenever the system indicates the existence of a current fault. See Multiple Trouble Codes. if multiple DTCs are found.

Diagnostic procedures are designed for use with current DTCs. As a result, they frequently suggest part replacement. When diagnosing a historic DTC, the procedures can be helpful but should not lead to part replacement without verification that the part is faulty.

Emissions-related DTCs will illuminate the check engine lamp for three warm-up cycles after the DTC has transitioned from current to historic.

Multiple Trouble Codes

All DTCs are assigned a priority number to determine the order in which they should be diagnosed. If there are multiple DTCs present, always diagnose the highest priority first.

• Complete the repair.
• Restore connections.
• Clear DTCs.
• Start vehicle. Perform several cycles to verify a code did not return.
• Perform odometer self-diagnostics test to verify repair and DTCs have been cleared. If any DTCs are still present, refer to Diagnostics (Pages 1-2).

Clearing DTCs

Clear DTCs after any diagnostic or repair procedure. The odometer is capable of displaying and clearing ECM, BCM, instruments, radio, and ABS DTCs. Once DTCs are cleared perform a road test to verify DTCs do not return. It is important to perform a road test and not simply start the motorcycle since some DTCs may require vehicle speed or other inputs to validate repair.

Security Lamp

See Figure 1-1. The security lamp turns on when:

• Current DTCs are present in the BCM.
• Non-emission-related DTCs are present in the ECM.

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