Electrical & Lights Adaptive Cruise Control (ACC) problem

Discussion in '8th Generation (2008-2015) [Acura TSX]' started by julekasMobilek, Friday 28th Jun, 2019.

  1. julekasMobilek Senior Member ★ ★ ☆ ☆ ☆

    Lithuania Julius Vilnius
    Hello fellas,

    I have encountered odd ACC problem, i cannot set current speed and/or resume to last used speed limit.

    Here is the video itself:

    Its kinda self explanatory.
    Tried to turn off and on again, as you can see LKAS recognizes lanes quickly (so camera working), but then i tried to set current speed limit, I got "error" ACC off. As you can see in brief moment the speed limit appears in about 0,09sec trough 0,11sec of the video, but after that immediately ACC cancels it.

    How to fix this?
  2. honda_saj Club Veteran ★ ★ ★ ★ ★

    United Kingdom saj east london
    honda HDS will be quickest way, possible causes can be brake or clutch switch faulty or incorrectly aligned
    MattBeardless likes this.
  3. MattBeardless Service Team H-Tune Staff

    United Kingdom Matt Derby
    As @honda_saj said. That looks to me like the clutch or brake switch is either faulty or incorrectly placed (so that it's constantly telling the system that your clutch is engaged, which'll disengage ACC).

    It's reasonably simple to diagnose for the brakes though, as your brake lights run from the same system. Please check that your brake lights aren't permanently on. If they're not, it's likely your clutch switch.

    Please let us know how you get on,

  4. julekasMobilek Senior Member ★ ★ ☆ ☆ ☆

    Lithuania Julius Vilnius
    Thank you guys for your opinions.
    The minor problem is that, that ACC is about 95% in working state :Smile:. To this day, I didn't encountered any problems after that video have been released.
    Although, I went underneath the brake pedal to look around, and a little bit fiddled the switch.
    Didn't do anything major, just disconnected the plug, pushed the brake pedal and saw how switches shaft is moving.
    My original intent was to take it out, and test by honda service manual, but I couldn't figure it out how to take it off, so i left it :Smile:


    on the other hand, clutch switch (i think) does not work with ACC system directly, because i can change my gears with clutch, while ACC is engaged and speed limit is set. While i'm changing the gear, ACC waits for gear to be changed and after that, it resumes to the speed limit.