CEL coming on while riding, stays on for a few minutes then goes back off. May happen in a few miles other times not so often.
Checked for codes. Only thing that comes up is d01Clr, d02Clr through d09Clr
That tells me, no codes set.
What's going on, The bike runs great. Don't know of anything done to the bike except cams changed and I don't know if the new ones are stock or not. Original owner not available to ask. Could different cams cause this. Spark plugs was changed last year also. Running 89 gas.

 

Hard to say what's going on, could be many things.....

First, I'd suggest using premium gas (91 octane) as a hedge against detonation, since you have an unknown cam and an unknown tune.....

I'm sure it's happened, but I've never heard of someone changing cams, and putting OEM cams back in... what's the point? Unless something breaks, that damaged the OEM cams....?

As to the check engine light... The ICM (carbs) and ECM (EFI) changed several times in the early twin cam engines... some minor and subtle, up to the '07+ with O2 sensors and closed loop portions of the tune... There were differences between how codes were captured, checked, and cleared...

A check engine light should register immediately, then turn to a historical code if it self corrects. I have to admit I was always befuddled by the early twin cam code reading protocols.... I am unsure how the 2001 codes work, and how a historical code shows itself...

Be that as it may, it seems you are getting an intermittent code situation that is quickly self correcting.... In most cases, those types of issues will continue until the code becomes permanent...

You can try to see if there are historical codes, or wait until it becomes a permanent code.... until then, it's hard to "diagnose" a check engine light without a code, or an felt issue with the way it runs....

Sorry I can't help with your particular issue..

FWIW... the only similar situation I've encountered, was on my '03 Heritage (EFI), when I could see the check engine light go on, then quickly go off. In my case, there was a historical code when I checked... It was a "front cylinder, no combustion" code... It turned out I had a bad front spark plug wire.. so I knew where to look and it was an easy fix...

 

SPEEDOMETER TROUBLE CODES

CODE - TROUBLE - WIRE COLOR
d01 - speed sensor power output shorted low - red
d02 - speed sensor power output shorted high - red
d03 - not used
d04 - not used
d05 - speed sensor return shorted high - white
d06 - speed sensor return shorted low - white
d07 - not used
d08 - peedometer power overvoltage - orange/white
d09 - speed output shorted high - white/green
d10 - speed output shorted low or open - white/green
5 digit number - speedometer pulses per unit"

 

What you describe sounds like you may have a weak electrical connection in the numerous plugs and connections.

You would think if it comes on long enough while running that it would store a code so it would give you some idea what system to look at.

Problem is it's pretty primitive a system compared to a car OB2.

Try unplugging the base of the speedometer and ECM and look carefully at the pins. Not sure were your grounds are but all mine are under seat just back of tank. Check them with a volt ohm meter.

Could even be a mechanical connection like ignition switch. It's not bad enough that bike quits but the low voltage signal pops the light on from the poor signal to the ECM.

 

Don't be so cheap use 91 or better gas.

 

A 93 uses the resistance of the spark plugs for knock (ping , pre-ignition ect) settings. However, I don't think the system is smart enough to throw a code for that.

However, for it to work properly, you need Harley's low resistance plugs. They are unique especially made to Harley's specifications.

Don't use car sparkplugs or fancy stuff. If you do, you have to drive it gently, in flat country ect to manually control to keep it from pinging. Not the best method.

 

Thanks, first thing I'll try is gas. Probably ride this afternoon, suppose to be low 80's here, and I need gas.
Am I checking it right on my 02 with EFI,
Hold reset button and turn on ignition
Display says "diag"
press reset button and display says "d01Clr"
pressing reset button steps through "d02Clr" and on up
This from my Harley Service Manual

 

Thanks kojak for posting those trouble codes....

I think I get it now...

OP, your codes "d01Clr, d02Clr through d09Clr" with the "clr" after them probably means they are a historical code.... Clear them...

If all the "clr" codes were present, numbers 1 through 9....and they come back, I believe RIPSAW has your answer in post #4.....

If it's just the 3 codes you posted, and they come back, they are pointing you towards a VSS going bad...

Good luck with your repair....

 

You can't read engine codes through the speedometer on an 02 - all you are checking is speedometer codes. Speedometer Diagnostics (reading engine codes through it) started in 2004.
If you do not have a code reader or scan tool, you have to jump 2 specific pins in the ALDL connector (where the scan tool hooks up). Once jumpered the CEL will flash out the codes.

 

Think Ed has the answer. I assumed too much that you didn't have a stored code and your 02 FI had the same system as my 04 Softail.

And he may be right but I think like my 93 Jeep system, you can set it to blink like this.

Try this.



Your problem probably is just an old stored code. Clear it and your good for another 20 years.