Fat Boy Engine light always ON

Discussion in 'Electrical' started by Burmie, Nov 1, 2010.

  1. Burmie

    Burmie Member

    Anyone, please shed some light on this problem. Red Engine light remains ON.
    Fat boy FLST 2001 model. 1450cc Fuel injected. Mileage 8 400km.
    Ign ON = Engine light ON for 4 sec. OFF for 4 sec. ON for 8 sec. Manual reflects this as Historical fault. Bike now has 20 000km on Speedo and done more than 50 starts.

    Problem. Engine light ON when running.

    Test I have done.

    • Linked pin 1 and 2 on diag plug.
    • Ign ON
    • Engine light flashes 6 times, 2 times 3 times, [23] flashes 3 times 2 times [32] 6 times, then 1 time ? and back to 2,3 and 3,2 then 6 etc (P0261,P0262,p0263, p0264)
    • Traced fault to FRONT injector, and Back injector. Bike done 8 400km tells me unlikely to have 2 injectors faulty. Harley Durban confirm this fault and want me to import 2 new injectors?
    • I carried out further tests.
    • Removed tank and injector plugs.
    • Measured resistance with 2 separate Fluke meters. Each injector measures 14,5 ohm. Spec is 13,7 to 15,2 ohm.
    • Observed wiring diagram and measured resistance between ECM (pins 21,19) and injectors. 0,3 ohm ea
    • Observed wiring diagram and measured resistance between ECM and ground. 0,3 ohm. (pins 10,28)
    • Measured battery voltage. 12,9 volts. standing.
    • Measured voltage at injectors plug for 2 seconds when ign On. Fuel pump fuse pulled = 12,6 volt on both injectors. 0,3 volt drop tells me all connections are clean and in good condition. Inspected all joints. Master relay clean and not showing volt drop across its contacts.

    Have done 50 starts by now, so expect historical fault to be cleared by now.

    My thoughts are now, as to whether the software in the ECM is compatible with the resistance of the injector coil. The ECM must measure the current drawn by the injectors, in a window, and if the resistance in the injector circuit changes due to coil failure or even a loose or dirty connection. A fault will be reported.
    My logic tells me the injectors are fine. Installing new ones I do not believe will sort out the problem.
    Can you advise?
  2. Hoople

    Hoople Account Removed

    See if the following method enables you to clear those codes. Don't know if it works but it came from HD themselves and it should work. Being able to clear codes and see how fast they re-appear will tell a lot of information as to "how strong" or dominant the errors really are.

    It would be very helpful to see a page or two of the bikes wiring. The basic ECM, injectors, main fuses, battery fuel pump etc. Your post count needs to be 5 in order for you to upload.

    See if the following works.

    To Clear Magnetti Morelli codes yourself.

    Disarm alarm if so equipped.
    Run/Off switch to OFF
    Ignition Key: ON,OFF,ON,OFF,ON (and leave ON)

    Press LEFT turn signal switch TWICE. Wait for 1 or 2 flashes..

    Press RIGHT turn signal switch ONCE => turn signal will flash 1 time

    Press RIGHT turn signal switch ONCE => turn signal flashes 2 times

    Press RIGHT turn Signal switch ONCE => turn signals flash 3 times


    TO CLEAR ANY CODES,,,=> PRESS & HOLD LEFT signal switch for 5 seconds. => turn
    signal will now flash twice to confirm memory is clear.

    Turn ignition OFF.

    See what happens!
  3. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

    Another quickie is to grab the injector wires about an inch from the connector and wiggle them while the engine is running (don't get burnt!). See if you have any change in the engine performance while you are doing this. Sometimes the injector wires can develop a stress fatigue that can be intermittent.

    Front Injector Problem (FL Models) - Harley Davidson Community

    It says FLs, but check it anyway.

  4. Burmie

    Burmie Member

    Thanks for your input. I ran the reset setup, which seemed to do all the correct flashing etc and then did the reset faults bit. However once i started the bike the red light came on for about 10 seconds them off for half a second and back on again. I have a new battery installed. I was wondering if when starting the bike the voltage gets pulled down and if the ECM is monitoring current drawn by the injectors, with the low voltage it will detect an out of spec injector for this short period, and latch in a fault. HD should have an initial start up monitoring delay, i would imagine.
    Got me stumped?
  5. Hoople

    Hoople Account Removed

    Get your post count up to 5 and then upload a couple of pages from the service manual showing the wiring diagrams of your ECM & injector wiring including the system relay.

    Have you made any changes to the wiring or injectors since this problem started. How are you checking the system relay contacts? Taking an ohm reading of them will not work.
  6. Burmie

    Burmie Member

    Thanks for your input. The light has been ON since day 1. As the machine was imported directly into South Africa and bypassed the dealer network (not sure if their was one here in 2002) the local Harley dealers are not over the moon to assist and we seem to have a lack of skilled technicians when it comes to the electronic side. All they want to do is replace parts at my cost. Kind of hit and miss.
    No changes to the wiring have been done and i assume the relay contacts are good based on the voltages measured at the injectors for the first few seconds when switching the ignition On.
    I have down loaded the full manual with all drawings from ebay and have been working with this info.
  7. Hoople

    Hoople Account Removed

    1) So the ONLY two codes you have ever seen and are presently dealing with are: DTC 23 & 32. Front injector open/low. Rear injector open/low.

    2) The clear fault error log procedure in entry point #2 of this thread DID in fact appear to work and did clear the codes. You were able to witness the LACK of the check engine light when the ignition was now turned on but the error codes re-appeared after 10 seconds of running time.

    3) If YES, Get your post count up to 5 in order to be able to post with attachments. Upload a couple of pages from your manual which show the fuses including the system relay, fuel pump, ignition switch, ECM and battery.

    4) As long as you can clear DTC's on demand using the posted procedure, the problem should not be too hard to resolve. It would be extremely difficult and time consuming to fix this problem yourself if you can not clear the codes "at will" and start with a new slate each time you make a simple test or change.

    5) **So we are SURE and can demonstrate to ourselves that we can clear the error log at will and before a 50 key cycle procedure.**
    Boot the bike WITHOUT starting it. Let the ECM finish it's boot. The "check engine" light does in-fact remain lit. Now clear the error log. Once again boot the ECM. The check engine light may now come ON, but will go OFF and remain off. Running the bike for 30 seconds re-logs a DTC of 23 & 32.