Check Engine Light

Discussion in 'Touring Models' started by 04 Ultra Classic, May 30, 2008.

  1. I have a 2004 Ultra Classic. Recently the Check Engine Light goes on and off intermittently at high speeds. No rhyme or reason as to why. I have since checked the diagnostic process and found code "P1356", "Rear Cylinder No Combustion EFI". Since I have cleared the code the Check Engine light has only come on once. Any help out there? Please and thank you.
     
    Last edited: May 30, 2008
  2. glider

    glider Veteran Member

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    Some things to check are the rear plug wire to see if it is on tight, the rear injector wire, give it a wiggle with the bike running at idle and see if it stumbles to see if you have the usual broken copper about an inch from the injector plug. They strapped the harness tight from the factory and with the rubber mounted engine, it damages the copper in the wire. The insulation is usually intact but the copper isn't inside. Lastly it could be an injector but this doesn't happen often.
     
  3. Hi Glider. Thank you for the info. I used your info on checking the codes and that saved me a sevice call. I have checked both plugs wires and they seem to be on tight. I will check out the rear injector wire to see if that might be the problem

    Thanks,
    04 U.C.
     
  4. glider

    glider Veteran Member

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    One other thing I forgot to mention, check the top of the spark plug where the wire snaps on to, they can loosen up and cause this problem also. It's threaded on do give it a twist to make sure it's tight.
     
  5. Hi Glider,

    I have already checked the plugs. I think I will also replace both spark plugs. Thank you.
     
  6. wildspirit97

    wildspirit97 Senior Member

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    I had the same thing I checked and changed the plugs,checked the wires 3 time and finally changed the wired and the problem was cured. I never would have imagined that plug wires would go bad after 5000 miles but thanks to Glider I changed them and fixed it.
    on mine the engine light would stay off while cruising at lower RPM's but when I hit the throttle the light would come on almost instantly.
     
  7. glider

    glider Veteran Member

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    This type of problem is usually in the secondary ignition circuits triggered by the ION sensing so it's relatively easy to find. Plug /wire or a coil connection to the plug wire is the possibilities.
     
  8. Thanks for the info. Going to get new plugs on Monday. See if that works first, then if not, I will probably replce the plug wires. Should I just use Harley replacement wires or do you have a better suggestion?

    Thank you
     
  9. glider

    glider Veteran Member

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    I say stick with the HD parts. They give you the least problems and work with the rest of the system with no problems.
     
  10. Thank you. I will let you know how I make out. All information is greatly appreciated.