2003 FLHRC engine light on
Seasoned HDF Member
Joined: Sep 2008
Posts: 14,143
Likes: 11,214
From: San Diego, CA
that's a lot of good info but i am not having any luck with the data connector/jump wire procedure. i jumped pins 1 and 2 (which are not marked but apparently i picked the right ones) with a female spade connector. however, when the engine light should have been displaying flashes for the codes i got only a single flash and then the light stayed on until i turned the ignition switch off.
You mentioned that pins 1 & 2 aren't marked.
Ed was telling you that the wires to the data plug terminals are color-coded, and getting the correct terminal pins jumped is essential for reading the codes.
Look back to one of the pages I shared with you, "Check Engine Lamp Diagnostics 4.5". It will tell you the colors of the wires to terminal pins 1 & 2. Then try again, making sure you are jumping the correct pins..
Double check, but I believe Terminal 1 is a light green/red wire and Terminal 2 is a black wire...
Last edited by hattitude; Nov 24, 2025 at 03:08 PM.
Thread Starter
|
4th Gear
Joined: Nov 2025
Posts: 8
Likes: 1
you are correct about that and i was incorrect about the pins not being marked! today i examined the plug extremely closely with my reading glasses and darn if the plug case isn't marked with the numbers 1,2,3,and 4 embossed into the top end of the mold along with the brand name "Deutch" (sp). the green and black wires coordinated with the pin numbers as you guys pointed out. However, did not matter as when i redid the procedure i got nothing. no flashes after the initial on-off-on-off. engine light stayed off for three minutes until i gave up and turned things off. i even tried replacing the female electrical connector with alligator clips and wire making sure they did not touch to no avail. me thinks the road king wants me to spend money on it one way or another aside from enjoying the ride!!
Thread Starter
|
4th Gear
Joined: Nov 2025
Posts: 8
Likes: 1
after no luck with DIY engine codes i took it to a reputable shop for them to read. they tried a lot of different go-arounds after the ECM read "loss of historical data" including rebooting, reprogramming, etc. no luck getting the engine light to go off. finally found that something got damaged in the ECM that causes this problem and will not allow some data being read. Bike still runs fine but the ECM will not function to read codes in the future. since this is the first malfunction the bike has had in 22 years i'll just ride on!
side notes: cannot get a new ECM from Harley any more. have to get one from the used marketplace. $300
possible cause of this was jumpstarting a dead battery off my Ford F150 pickup
side notes: cannot get a new ECM from Harley any more. have to get one from the used marketplace. $300
possible cause of this was jumpstarting a dead battery off my Ford F150 pickup
after no luck with DIY engine codes i took it to a reputable shop for them to read. they tried a lot of different go-arounds after the ECM read "loss of historical data" including rebooting, reprogramming, etc. no luck getting the engine light to go off. finally found that something got damaged in the ECM that causes this problem and will not allow some data being read. Bike still runs fine but the ECM will not function to read codes in the future. since this is the first malfunction the bike has had in 22 years i'll just ride on!
side notes: cannot get a new ECM from Harley any more. have to get one from the used marketplace. $300
possible cause of this was jumpstarting a dead battery off my Ford F150 pickup
side notes: cannot get a new ECM from Harley any more. have to get one from the used marketplace. $300
possible cause of this was jumpstarting a dead battery off my Ford F150 pickup
Seasoned HDF Member
Joined: Sep 2008
Posts: 14,143
Likes: 11,214
From: San Diego, CA
after no luck with DIY engine codes i took it to a reputable shop for them to read. they tried a lot of different go-arounds after the ECM read "loss of historical data" including rebooting, reprogramming, etc. no luck getting the engine light to go off. finally found that something got damaged in the ECM that causes this problem and will not allow some data being read. Bike still runs fine but the ECM will not function to read codes in the future. since this is the first malfunction the bike has had in 22 years i'll just ride on!
side notes: cannot get a new ECM from Harley any more. have to get one from the used marketplace. $300
possible cause of this was jumpstarting a dead battery off my Ford F150 pickup
side notes: cannot get a new ECM from Harley any more. have to get one from the used marketplace. $300
possible cause of this was jumpstarting a dead battery off my Ford F150 pickup
Glad you got to the bottom of the issue... I hate electrical stuff, makes my head hurt.
Ed is a valuable source for information, and it appears also some obsolete parts..
Way to go Ed...!As to the jump starting, there are numerous reports of collateral damage caused by jump starting a Harley from a running vehicle... Those reports caused me to get a Norco jump pack for my bikes. It's also small enough to carry on a long multi-day trip, if I happen to be too cheap to replace an older battery before a trip..
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Glad you got to the bottom of the issue... I hate electrical stuff, makes my head hurt.
Ed is a valuable source for information, and it appears also some obsolete parts.. Way to go Ed...!
As to the jump starting, there are numerous reports of collateral damage caused by jump starting a Harley from a running vehicle... Those reports caused me to get a Norco jump pack for my bikes. It's also small enough to carry on a long multi-day trip, if I happen to be too cheap to replace an older battery before a trip..
Ed is a valuable source for information, and it appears also some obsolete parts..
Way to go Ed...!As to the jump starting, there are numerous reports of collateral damage caused by jump starting a Harley from a running vehicle... Those reports caused me to get a Norco jump pack for my bikes. It's also small enough to carry on a long multi-day trip, if I happen to be too cheap to replace an older battery before a trip..
Even then I am leery but at least that way you wont have a 100-200 amp auto/truck alternator going to town on a 40 amp bike. Your risks are much less that way.
Last edited by Ed Ramberger; Jan 14, 2026 at 06:19 PM.
Thread
Thread Starter
Forum
Replies
Last Post