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One person that's an expert on this is @Ed Ramberger . Hell get a notice for me tagging him.. He should have some info..
For this model, Historic trouble codes are not seen using check engine light diagnostics, they are only read with a scanalyzer.
At initial key on, if the CEL comes on for 4 seconds and goes off and stays off, it has no current codes - but may have historic codes
If it comes on for 4 seconds, goes off for 4, then on for eight, then off, there is a functional error - codes 52-55 and 56. It may have historic codes.
If it comes on for 4, off for 4, then comes on and stays on it had a current code/fault. It may have historic codes.
Last edited by Ed Ramberger; Oct 21, 2024 at 10:15 AM.
My 2002 FLHTCUI did that after high speed runs. Changed spark plugs and all was well.
The 02 has a Delphi system that uses the plug for ion sensing. The MM 2000 does not..
It does being up a thought tho.. I don't know if MM senses coil primary voltages injector drive voltages like the Delphi but maybe the coil promay or one of the injectors has increased resistance and the ECU senses the wrong voltage at higher Rs?
I'd start by checking wires / connectors on those locations.. Check resistance on the coils and injectors also. Tug on the wire going into the coil and injector connectors. If stretchy, they are likely broken inside.
The 02 has a Delphi system that uses the plug for ion sensing. The MM 2000 does not..
It does being up a thought tho.. I don't know if MM senses coil primary voltages injector drive voltages like the Delphi but maybe the coil promay or one of the injectors has increased resistance and the ECU senses the wrong voltage at higher Rs?
I'd start by checking wires / connectors on those locations.. Check resistance on the coils and injectors also. Tug on the wire going into the coil and injector connectors. If stretchy, they are likely broken inside.
on mm a coil fault will stay current until the system sees it exercised again and resolved. So if it faults and corrects light off.
To be sure and start OP may want to verify charging system if doesn not have a tuner or scanalyzer to read codes.
Last edited by Ed Ramberger; Oct 21, 2024 at 11:44 AM.
So if it were a loose connection or even higher resistance where it might show up with RPMs, it would correct itself as the RPMs dropped?
@Max Headflow It must go through a start sequence, so I do not interpret it as resolving while running. But that is my read on the language. I cannot say with 1000% certainty that it would not resolve while running but I doubt it.
Also if the bike has a powercommander on it, remove it and see if problem resolves - unless the build is so radical it would be unsafe for the engine to run it
Last edited by Ed Ramberger; Oct 21, 2024 at 02:39 PM.
For this model, Historic trouble codes are not seen using check engine light diagnostics, they are only read with a scanalyzer.
At initial key on, if the CEL comes on for 4 seconds and goes off and stays off, it has no current codes - but may have historic codes
If it comes on for 4 seconds, goes off for 4, then on for eight, then off, there is a functional error - codes 52-55 and 56. It may have historic codes.
If it comes on for 4, off for 4, then comes on and stays on it had a current code/fault. It may have historic codes.
Looks like I had a typo - the last line of this should read "If it comes on for 4, off for 4, then comes on and stays on it has a current code/fault. It may have historic codes."
That manual says you can use the check engine light for diagnostics.. It seems to say that codes are stored and can be dumped so you should get historic too..
Not correct..
If you have a historic code, the light don't stay on when ignition is turned on like you said, it goes out after 8 seconds.. IIRC it's pretty much the same as early delphi.
Last edited by Max Headflow; Oct 21, 2024 at 04:15 PM.
As I said in post 12, per the manual historic codes are only obtained through the scanalizer only. Last paragraph states this below. Not sure exactly the confusion but will gladly try to figure it out. Here is my take on it. A TP has a code. It is not resolved, the ECM sees it and keeps it as current which is readable through the scanalyzer or light. If it resolves and the ECM sees a start cycle, it goes historic and can only be read through the scanalyzer.
Last edited by Ed Ramberger; Oct 21, 2024 at 04:01 PM.
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It seems to say that codes are stored and can be dumped 
