ECU/WIRING LOOM 5th generation

Hi all.

My Vfr 1998 model is playing up.

The power was dropping when head lights were on and the FI was flashing.

Luckily I had a 3mth warranty on the bike so returned to dealership.

They ordered a new ECU unit and they tested it but when bike heats up FI light show’s up again.

They still have the bike and are now ordering a new wire loom to see if that’s the problem.

Has anyone experienced same problem on 5th generation Vfr.

Thanks for your help.

Cheers.

This sounds like a typical earth block problem to me. There is a common earth point in a block taped into the loom on the left side below the seat, if this gets some corrosion then weird things happen to the electrics. If cleaning the block doesn't fix it, then soldering all the green earth wires together and connecting these to the frame has been a permanent solution. A new wiring harness would also be a fix if money was no object!

Another problem causer on top of what Terry has mentioned. Is your Main Fuse B 30amp.

The fuse and its wiring can suffer badly from overheating and burnt connections. Both your headlights and all ECM power comes from Main Fuse B on a 5gen. So have a good look at this fuse and wiring. Its located next to your starter relay, not the one thats in it.

Good luck.

Hi all thanks for your reply and help .

The bike is still with dealer and they are ordering a new wire loom .

As their mechanic ie Honda training still cannot find the source off fault.

I may have to pass on your information to him.

Cheers

Paul

Yipes - that sounds like a lot of parts and labor for something they hope will fix the issue.   When it comes to electrical systems,  I'm not sure technicians get the training they should.  A power probe should be in every tech's toolbox.  I've gotten away with a digital voltmeter, but should bite the bullet and get one myself. 

Throwing parts at bikes seems to be today’s MO for motorcycle repair, instead of actually diagnosing issues. Why? There are fewer actual technicians in shops, these days. 

15 hours ago, zanshen

Hi all thanks for your reply and help .

The bike is still with dealer and they are ordering a new wire loom .

As their mechanic ie Honda training still cannot find the source off fault.

I may have to pass on your information to him.

Cheers

Paul

That's surprising coming from a Honda dealership. Your fault is not an uncommon one, and there are so many things the require checking prior to concluding the ECM is at fault, would also be surprised that it needs a whole new wiring loom, very doubtful. All relevant Grounds and Power sources need to be confirmed from the Battery to your ECM, before even thinking of replacing the entire loom, or ECM.

Given the complexity of an ECM its amazing that it is probably the most reliable device on your bike.

As ducnut states, simply throwing parts at a bike is a very poor, time and money wasting, fault finding technique. I would have expected better support from a Honda dealership. Lucky its a warranty issue and hopefully you're not out of pocket. You never know, if they keep fitting new parts for you, you may end up with a new bike!

Good luck and keep us posted.

Ah, the warranty - was it supplied by the dealer from their resources or a 3rd party vendor?  If the latter that may account for the shotgun approach to the repairs.   The other odd thing is no mention of whether they checked for any stored codes as the cause of the FI light.  Or did they?   Even techs make the mistake of presuming two separate phenomena are related.  They could be, but it is illogical to conclude so without proper  diagnosis. 

To answer the OP's question about whether this has happened to anyone else on here, maybe an easier way to phrase it would be "who has it not happened to?"  Electrical problems on this forum are only slightly less common than social diseases in a brothel!   

Hi thanks for your help.

The mechanic is Honda trained but it’s not a Honda dealership.

They have checked the electrics as I have been told that is why they have ordered the ECM and loom.

Its no cost to me ,if they cannot rectify it then a refund I will seek.

 Thanks again 

 Paul 

Throwing parts at problems isn’t isolated to this market, it just seems to be the way it goes at many levels. What’s worse even for good techs is when trying to keep cost low, parts & labor is high and having to explain to a customer that you’ve fixed a problem just to uncover another problem sucks….. I work in a field dealing with this all the time and it can be stressful. But like Cogswell said, if the warranty is covering then the dealer will continue to reload the shotgun as long as there’s no push-back. 

Yes mate,

I popped in to the dealer yesterday and they have  new wire loom ready to install.

I asked them did they try any the solutions that was advised  on here and they confirmed they did 😏.

So they if that doesn’t work then it looks like a refund or they source me another 5th generation.

 Thanks 

Paul

zanshen, 9/12/2021 at 8:00 PM

Yes mate,

I popped in to the dealer yesterday and they have  new wire loom ready to install.

I asked them did they try any the solutions that was advised  on here and they confirmed they did 😏.

So they if that doesn’t work then it looks like a refund or they source me another 5th generation.

 Thanks 

Paul

Most unusual for the problem you have that the whole wiring harness should need replacing! However, as its a warranty issue, who cares? As long as they fix it for you. I suspect that any of the suggestions you may have made from the info here, they most certainly would say "yeah we've checked that" to save face!

Keep us posted.

Cheers.

10 minutes ago, Grum

Most unusual for the problem you have that the whole wiring harness should need replacing! However, as its a warranty issue, who cares? As long as they fix it for you. I suspect that any of the suggestions you may have made from the info here, they most certainly would say "yeah we've checked that" to save face!

Keep us posted.

Cheers.

Yes mate exactly .

Hi all hope you’re well .

Got bike back and all is running well.

They replaced the wiring loom and that seems to have been the problem.

On another note does anyone know  where I can source this Allen bolt for my 1998 mirror.

Thanks again.

Paul

any corner hardware store should have them. Also bicycle shoppe

Can also order them from here: 

https://www.mcmaster.com/screws/rounded-head-screws/hex-drive-rounded-head-screws/metric-alloy-steel-button-head-hex-drive-screws/

4 hours ago, DannoXYZ

any corner hardware store should have them. Also bicycle shoppe

Can also order them from here: 

https://www.mcmaster.com/screws/rounded-head-screws/hex-drive-rounded-head-screws/metric-alloy-steel-button-head-hex-drive-screws/

Thanks mate 

23 hours ago, zanshen

Hi all hope you’re well .

Got bike back and all is running well.

They replaced the wiring loom and that seems to have been the problem.

Good news you have it sorted. Having the loom replaced to fix your issue pretty well confirms what Terry suggested about the earth block, a junction point of 12  ground seeking wires built into the loom, then with 2 wires going to a frame ground. Many issues, including yours, are caused by problems with the earth block. Simply soldering all these wires together permanently fixes the issue......or you could replace the whole loom!

Hope the bike gives you no further headaches a well cared for 5th gen is a ripper bike. :wheel:

If anybody is wondering where to find the ground block, it is here, wrapped in black tape from the factory. 

17 hours ago, Grum

Good news you have it sorted. Having the loom replaced to fix your issue pretty well confirms what Terry suggested about the earth block, a junction point of 12  ground seeking wires built into the loom, then with 2 wires going to a frame ground. Many issues, including yours, are caused by problems with the earth block. Simply soldering all these wires together permanently fixes the issue......or you could replace the whole loom!

Hope the bike gives you no further headaches a well cared for 5th gen is a ripper bike. :wheel:

Thanks again mate 

zanshen, 9/19/2021 at 1:48 PM

Hi all hope you’re well .

Got bike back and all is running well.

They replaced the wiring loom and that seems to have been the problem.

On another note does anyone know  where I can source this Allen bolt for my 1998 mirror.

Thanks again.

Paul

[image: 730A5544-CB93-4A3A-B7BD-DB205C3E7F11.jpeg]

The problem is probably more than the rounded bolt head.  It probably got rounded because someone was trying to tighten it around an increasingly slipping mirror shaft.  

FYI, you can directly swap the mirrors from the Y2k-01 model onto your '98; those mirrors don't have the "condoms" and generally work better.  You can also get aftermarket Y2k mirrors, but I've never found any non-OEM versions with the same quality as OEM.

Ciao,

JZH

1 hour ago, JZH

The problem is probably more than the rounded bolt head.  It probably got rounded because someone was trying to tighten it around an increasingly slipping mirror shaft.  

FYI, you can directly swap the mirrors from the Y2k-01 model onto your '98; those mirrors don't have the "condoms" and generally work better.  You can also get aftermarket Y2k mirrors, but I've never found any non-OEM versions with the same quality as OEM.

Ciao,

JZH

Thanks again mate.

So the Yk2 bolt straight on then.

37 minutes ago, zanshen

Thanks again mate.

So the Yk2 bolt straight on then.

You’ll need 2 of these, as the ‘98-‘99 base is a different shape from the ‘00-‘01. 

ducnut, 9/20/2021 at 11:49 PM

If anybody is wondering where to find the ground block, it is here, wrapped in black tape from the factory. 

[image: 7BACC6E7-C9E3-4C89-B4BD-80FDE7DE6790.jpeg]

+1 And on a 5gen its located just above the chain guard.

[image: IMG_0638.JPG]