I’ve heard of ISGs that were in need of replacement. Not too many though and I don’t recall the symptoms.

It does seem odd to me that Honda would use a customers bike as a donor for trouble shooting parts. A dealer has their own bikes they could use for that.

 

Earthdog I would check with Fred H or ssncob and see what they would charge to install the ISG.

Seems like there would be a bench test that could be run on the ISG after it's been pulled??????

 

... whacky stuff happened...

What do you mean by that?

 

When you depress the start button it fires up and runs for 1-2 second shuts off, on its own then restarts fires up and dies. The mechanic has confirmed that occasionally it does it a third fire up and shutdown. Then you can press the start button and it does the cycle again. Eventually you will kill the battery once a new battery is installed it will do the same thing when pressing the start button.

 

I doubt very much if Honda told the dealer to pull one from a donor bike. Sounds like the dealer has no idea how to test the ISG, if that is fact the problem' or just doesn't want to be bothered troubleshooting the system.
BTW, if I ever found out a dealer was using parts from my bike to test another one, there would be a nasty letter sent to mother Honda and have an attorney on hand.

 

I purchased a 2018 DCT and within 2 days it won't run. It was running fine parked it tried to start it and whacky stuff happened and trailed it to Dealer.(It has had the bolt recall done 5 months ago.)

The Dealer is telling me Honda told them to pull a known good ISG out of the next bike they get that needs the recall work and install into mine to confirm ISG is the issue.

1 Would Honda suggest this? I would be pissed if you were pulling parts of my bike to test in a problem bike.

2 Is the ISG failing common?

3 What causes the ISG to fail?

4 What are the symptoms of a failed ISG?

5 Where is the cheapest place to by a replacement? Right off the bat they are telling me it's a $2850ish part plus labor. They said I can buy the part elsewhere and bring the part to them.

6 I pushed hard that it seems like a bike with under 24k shouldn't have the issue and they gave me Hondas number. Is there a good tactic to use to attempt them to cover the cost?

I just find it shocking Honda would tell them to pull a part off another persons bike to test. They were straight up saying they weren't going to pull the part off one of their floor bikes to check it.

I would appreciate any thoughts as I have little confidence in the dealer.

Are you saying that you had only owned this bike for 2 days before this started happening? Did you buy your bike from this dealer? I too seriously doubt that Honda told them to use an ISG from a customer's bike to diagnose yours. I would run, not walk, away from that dealer. My first call would be to corporate Honda!

 

Correction 3 days and I had put 200 miles on it. I have owned 2 other wings and this one was in great shape.

I am only the messenger on what the dealer said. I thought it was crazy myself. I went down a few hours ago to talk directly to the mechanic instead of the service writer and he clearly said Honda directed him too. I am shocked there is not a testing method outside the chassis. Unfortunately I am not aware of a good trustworthy dealer in Metro Atlanta. I or my buddies have had poor experiences with them all.

 

ISG should set a code if it is the source of the problem. If there aren't any codes, then I'd probably guess a bad fuel pump.

I don't think I'd install an ISG from someone elses bike into another customers bike. What happens if the ISG from the other bike gets damaged during the process. I'd be really mad if I brought my bike in for a recall service and found out they pulled parts off it to troubleshoot some other bike. This is just wrong on so many levels.

 

ISG should set a code if it is the source of the problem. If there aren't any codes, then I'd probably guess a bad fuel pump.

I don't think I'd install an ISG from someone elses bike into another customers bike. What happens if the ISG from the other bike gets damaged during the process. I'd be really mad if I brought my bike in for a recall service and found out they pulled parts off it to troubleshoot some other bike. This is just wrong on so many levels.

@Fred H. They say there are no codes and tell me they have confirmed the Fuel Pump is good. If a bad ISG throws a code then that implies it's not the issue. IMHO but I don't understand in general.

 

I would appreciate any thoughts as I have little confidence in the dealer.

I would have zero confidence in that dealer, and would find a different one to take it to.

Replacing expensive parts only to find out they weren't the cause shows they really don't care about you or your bike. Find a dealer that will take the time to properly troubleshoot the problem. I'll bet you a box of doughnuts your ISG is just fine.

 

By the way, you might want to check the two fuses mounted below the fuse box. They have been known to get corrosion due to moisture intrusion in the fuse terminals and cause issues.

 

What would happen if by chance the sidestand switch went bad ? Could that cause the starting problem ?

 

It's rare, but it happens. I had an ISG go bad shortly after I bought my then-new 2018. There was only one symptom: The bike would not start or even turn over. The dealer tried everything he and Honda could think of until Honda finally authorized a new ISG which got the bike going again. Because no one knew what the problem was, Honda was initially reluctant to throw a very expensive part at an undiagnosed problem. The dealer had my new bike for months, but once every other trouble-shooting possibility was eliminated, Honda gave the go-ahead. As the mechanic relayed it to me, the ISG, which is a French-made part that Honda uses, has no diagnostic port, meaning there is no way to test it.

 

There is a guy here in the German Goldwing forum, who experienced a bad ISG and got this successfully repaired by his dealer.
His bike showed the symptom, which @gkarasik reported in post #14.

...There was only one symptom: The bike would not start or even turn over...

The dealer said: "...The coal holder was jammed..."

I asked the owner which code the dealer pulled but I haven't received an answer until now.

 

There was a rider here in the last few weeks that had a similar issue .. when he held his start switch down to start without releasing it his bike kept running normal. Once he released it his quit…. You might try that. He had a broken switch.

 

I'm sad to admit this, BUT with ALL the new problems the 2018 (and newer machines) are having, I've been quite hesitant to purchase a new bike, when my 2010 (with 80,000 (ish) miles bike, is running perfect....
I'm the only one to ever ride my bike, so I know that every mile has been babied, and never beat on, and of course you all know that clean fresh oil has always been splashing around in my motor since day one.. This is another reason that I'd never buy a used motorcycle.....

Ronnie
9/11/25

 

I'm sad to admit this, BUT with ALL the new problems the 2018 (and newer machines) are having,

What about those owners who've never had a problem with their 2018+? I know at least 3 with over 150,000 miles on a 2018 and never had an issue. I'm still sitting just under 80,000 with no issues. But yeah, " ALL the new problems the 2018 (and newer machines) are having"...PUH-LEEZE!

 

I looked at Partzilla once and it showed a new ISG would sell for around $2000US. I can see where nobody would keep one in stock, or even order one if they weren't sure it was bad.

 

I looked at them to get the part since the Honda Dealer wants MSRP for the part. The issue with them (as of yesterday) they don't have it and no eta from Honda.

 

As previously pointed out by others on this thread, it could be something as simple as a bad start switch. I'd probably also remove those two fuses I mentioned earlier and inspect the fuse holder contacts for corrosion or heat damage.

Smart mechanics always check the SIMPLE stuff FIRST before replacing expensive and labor intensive parts.

 

Smart mechanics always check the SIMPLE stuff FIRST before replacing expensive and labor intensive parts.

This is likely part of the problem. It seems these days dealership "mechanics" are more into "swaptronics" than actual detective work. If the computer can't tell them the problem and fix, they just start guessing.

 

Have you checked your grounds and battery connections.
These things do weird things when grounds start to fail.

 

If you're already checking the grounds and connections, you might as well take the time to clean those connections.
Just a thought..

 

The previous owner of my bike had to have the ISG replaced when it was relatively new. There have been no problems with it since and has over 51000 miles on it now. BTW, I had both bolts replaced during the primary bolt recall.

 

Deleted.

 

Some things can't logically diagnosed even with a scan tool, error codes ect. I suspect the ISG falls into this category. Sometimes part replacing is the only way. Replace and hope and pray, if it doesn't work replace next most logical part,sad but true unfortunately.
Zenith service manual on the first of the TVs that went digital procedure according to the service manual, "replace most logical item, if unsuccessful replace 2nd most logical, if unsuccessful replace 3rd ect". A dumb as crap way to repair anything, but the way things have gone. Complex crap, expect complex repair and a lot of trial and error.

 

Some things can't logically diagnosed even with a scan tool, error codes ect. I suspect the ISG falls into this category. Sometimes part replacing is the only way. Replace and hope and pray, if it doesn't work replace next most logical part,sad but true unfortunately.
Zenith service manual on the first of the TVs that went digital procedure according to the service manual, "replace most logical item, if unsuccessful replace 2nd most logical, if unsuccessful replace 3rd ect". A dumb as crap way to repair anything, but the way things have gone. Complex crap, expect complex repair and a lot of trial and error.

Yes, I believe that you're correct about this. I think we make a mistake by comparing trouble-shooting current-generation, electronics-laden parts with trouble-shooting older-generation, purely--or mostly--mechanical parts. There are very few Freds, Jerrys, Murfs, or Techdudes. (We have a highly unusual cluster here of hybrid mechanical/electronic engine whisperers, and I apologize if I've left anyone out). There aren't many motorcycle-mechanic-school grads who are going to be able to diagnose and repair complex electronics-laden parts and their CANBUS inter-relationships with other complex-electronics-laden parts. Unlike our resident geniuses who can--and who have the time to--track down cascading failures at the circuit-board level, "normal" moto-mechanics are limited to using diagnostic machines to ID bad sub-subsystems and swapping them out in order to get modern vehicles back on the road. Imagine what they'd hear from a customer if they handed him bill for umpteen thousands of dollars of diagnostic time in order to find and switch out a failed diode.

 

Back in the 90s, I had a chance to look at the service manuals for an IBM 4381 computer. Not the biggest they made but mainframe-sized. The troubleshooting section was nothing but "if this symptom is present, change this board. If still present, try this one". At the end of this rabbit hole, the last line read "Invoke your support structure."😑

 

Did this motorcycle ever get fixed?

 

Nope still at dealer waiting one a loaner ISG to test from Honda.

 

BTW: I replaced the battery that day in the parking lot with a new one.

This is the continuation of my other posts on my newly purchased 2018 DCT (with completed recall for Fuel Pump and UBS Bolt) prior to me. It worked flawlessly for the first few days. I was riding fine I parked the bike, went into my stop for an hour, came out, and this is what happens:

Ignition on all displays looks normal. Press Start/ Stop button.
Starter engages; attempts to start do not fire up.

If you hold down the start/stop button,
Starter engages; attempts to start acts like you removed your finger from the button and will engage the starter again and attempt to start 2-3 times before stopping as if you remove your finger from the button.

On all attempts no fire up from the engine.

Trailered bike to Dealer 1 month ago. Per Dealer and Honda Tech Line, they said it was the ISG. Well, today (1 month later they got an ISG to test), that was proven wrong. The The ISG did not make any difference.

The Tech/Dealer is stumped and will be calling Honda again later today. The Tech said he has no idea; maybe a PCM, but will see what Honda says.

I read somewhere previously that it could be the switches, but the dealer says it is not possible.

Any thoughts? It stinks having a new bike for 2 days (selling my 2005) and losing it to the dealer for a month.

I have set up an appointment at another dealer Southern Powersports on the 8th as they tout having 4 certified TRUE Honda Techs. I would prefer not to have to pull it out of my local dealer and trailer it 2 hours away, but I am not sure what else to do.

Any ideas would be great. I am going to try and get a video of the behavior from the dealer later today.

 

You mentioned that you changed the battery…check the connections to make sure they’re tight…I had a similar situation last month…thankfully the bike started…got it home…bought a new battery the next morning…when I went to install it, I discovered the positive terminal was loose…tightened it and all was well…and no issues since….good luck…ride safe…

Scoty

 

Why a new thread?

I think Admins should merge this thread with the original thread just to keep everything in one place.

I’m glad it wasn’t the ISG….

Has the fuel pressure been checked? …. I can’t remember the details in the other thread.