Harley Cruise Control Diagnostics
Bob LaRosa & Mark DiPietroDescription
If your Harley cruise control has an issue, there is an interactive cruise diagnostic test that can be performed on the motorcycle without the need for any diagnostic service scan tools or computer.
The Harley cruise control function is governed by the motorcycle’s ECM (or engine control module). The ECM monitors the vehicle speed sensor (VSS) to establish the bike’s current speed. The ECM then modulates the throttle control actuator to maintain a constant vehicle speed. When cruise control is enabled, the orange cruise lamp will change to green. The ECM monitors the engine RPM and the output signal from the vehicle speed sensor. Then, the ECM signals the throttle control actuator to open or close the throttle to keep the speedometer output speed signal constant.
The ECM will automatically disengage an active Harley cruise control mode if it receives one of the following input signals:
- -Front brake is applied
- -Rear brake is applied
- -Throttle is rolled forward (throttle roll off/cruise disengage command)
- -Clutch lever is engaged
- -Wheel slip is detected (an ECM detected jump in RPM)
- -Pressing cruise switch
- -SET/- switch is held in until the motorcycle speed drops below thirty miles per hour
- -RESUME/+ switch is held in until motorcycle speed goes above ninety-three miles per hour.
Bob and Mark give us a sequence demonstration for entering and moving through the cruise diagnostic mode. The illuminated amber/orange cruise light changes to green for every tested function.
If your Harley cruise control is not functioning correctly, you may have one of the following conditions to pursue:
- -Throttle position faults P0120 & P0220
- -Vehicle Speed Sensor faults P0501 & P0502
- -Cruise control switch failure
- -Front or Rear brake switch failure
- -Throttle position error P2135
- -Flash memory error P0605
- -ETC limited performance mode
The most common reason for inoperative or intermittent cruise failure is from a broken or misaligned front brake switch. If your cruise is not working, look behind you. See if your brake light is stuck on. Could be an easy fix.
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13 Responses to “Harley Cruise Control Diagnostics”
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When I pressed the cruise control to set, it stays green. It does switch between amber and green going through the function test
Do you have an updated guide for M-8, specifically 2021? Thanks
My amber light wont even come on
Hello Rick I have a 2015 ultra classic, my cruise control light come on, but the cruise is not working, also the light that tells me what gear I am on, is not working. Any help please?
</strong> Vehicle Year / Make / Model: 2017 HD street glide special Is there a way to increase the top MPH in the cruise control? It seems that my speedometer was showing 93 mph top-out cruise control speed while everyone else's bike was set at 85 mph during a recent group road trip. I could never relax my throttle wrist because of this issue. Can anyone help?
I've got an 05 Ultra Classic Electra Glide. The cruise control switch powers the cc light, can't set cruise. Brake light does not flicker or stay on. What do I need to check next?
I have a P 1502 error code and a Jiffy Stand error going through my display. I can't engage cruise control.
My 05 rkc the set/res switch makes it green, nothing else does.. ideas?
RK I followed the video and all checks where good. But on my last ride I would set the cruise control lamp would go to green and hold for a few seconds the kick out and go to red. Any suggestions?
I have a 2013 Anniversary Road King. I was on a trip last year and the cruise disengaged while riding and has not worked since. Should the procedure you outline to show cruise trouble codes work on a 2013 Road King. The reason I ask is that I have tried them and they do not seem to work on my bike.