Brake light stays on - not the common problems

Hi Gang, looking for some help here. Please read the whole thing before jumping to conclusions.

I have a 2006 US spec 1300A with a problem with the brake light staying on when the key is on.

The common problems have all been tested: switches, relay, lever and pedal return. Switches were removed from the circuit. The light was still on. Sounds like a short, right? I took it to the local Yamaha dealer.

They told me there were two open recalls on the bike (are there any others, and where do I find them?):

1) ground wire sub-harness. If that was burned or melted they would do:

2) full wiring harness.

There was no burning so they did #1. Light was still on.

Then replaced the relay. Light was still on.

No shorts were found.

Then they replaced the full harness (#2) as directed by Yamaha. Light was still on. Now they're scratching their heads.

Unplugged the entire front harness, just in case. No change.

Took a taillight from the shelf and plugged it in. No change, the light was on with the key on.

The next thing they are thinking is it could be the ABS ECU. I won't know until Wednesday this week if that fixes it. This could get expensive.

Please read on... could this be related?

I've read about "altitude sickness", but I'm near sea level, and ABS light coming on, and it was coming on (It wouldn't flash, just come on) but would go off when the key was turned off. Wouldn't come back on for several miles to a day or more. But THIS issue started shortly after I popped a front piston while bleeding the rear caliper. Yes, dumb, I know. But I bled it and it appeared to be OK. This was 2-3 weeks before I noticed the brake light issue.

I tipped the bike over in my steep driveway a week or so before I noticed the brake light on (yes, that was REALLY dumb), could there be any connection there?

Please help if you know something about the ABS ECU and the brake circuit. I'm at the dealer's mercy here. Any other theories or thoughts are welcome. By the way, the bike was running fine with no problems other than the brake light and ABS light. It has now been at the dealer for 5 weeks.

Thanks in advance, Pete

The service manual has the tests you can perform on the ABS system, need the ABS test coupler or can short out the wires to enable the test mode.

Could be something silly like the connector for the RHS switch block ?

A constant ABS light means that the fault is current / hard on, should be easy to diagnose in test mode.

Short in one of the tail-light bulb-holders?

First thing I'd do is find which circuit is sending power to the brake light circuit, pull fuses until the brake-lights go out.

The ABS unit monitors the brake light circuit, but I'd consider it unlikely it was sending power to the brake lights. The ABS unit can be unplugged, if that doesn't cure the problem, it definitely isn't the (extremely expensive) ABS unit.

This would have absolutely nothing to do with "altitude sickness." That was an air/fuel ratio issue. Nothing else.

I'd follow the advise above as a good starting point. You're sure the pin that is engaged by the brake lever is not stuck? Even if the lever is clean, but a lack of maintenance let that cylinder get very gummed up, it could stick. Not likely, but possible; especially if someone was lubing the thing with WD40. That could explain your flashing ABS light, but not your brake light.

The brake lights turn on by means of applying +12 volts to the brake filaments, so there has to be an unintended voltage source connected to the brake lights. Normally, the ECU turns on a relay letting the relay contacts supply the 12 volts. At the bottom of the list of suspects would be a relay with stuck contacts. Next up would be some left over farkle wiring from a previous owner, perhaps a brake light strobe gone wrong or trailer wiring. As unlikely as it may seem -- the world works in strange ways -- the tail light filament can break and drop down and short to the brake light filament causing the brake lights to be on 100% of the time. I know you checked one light by replacing it, you should try the other light too before doing anything else. If that doesn't resolve your problem you are looking for a 12 volt source supplying power. It's easier to get a short to ground, unintended +12 volts should be fairly easy to find.

Give any dealer your VIN and he can tell you what recalls were open for your model year FJR and also tell you which have been done by a dealer. There was the meter assembly replacement due to an instantaneous fuel mileage reading stuck at 17; this also resets the odometer back to 00000 miles. There was the altitude sickness recall which replaced the ECU. And, as you know, there was the ground harness recall.

The ABS flashing is a separate issue.

The brake light system on 2nd Gens and later is a bit more complex than earlier models. It is a "fail safe" system, meaning that almost any failure of the brake system will leave the brake lights in the "on" state Here's a description of how the brake lights work on a 2nd Gens:

The brake lights source their 12V power from the signaling system fuse (brown wire). That power is switched by the brake relay which goes off to the bulbs (yellow/green). This power goes through some Normally Closed (NC) contacts of that relay, which means you need to energize the relay to turn OFF the brake lights (counterintuitive).

The brake relay is normally energized (when you are not braking) by 12V signal fuse power (brown). From there it passes through coupler #5, then through the NC contacts of the front brake switch (becomes green/yellow), then through coupler #2, to the relay. The negative side of the relay coil (brown/black) goes through the rear brake switch's NC contacts to frame ground (black). An open circuit anywhere in this path will cause the relay to remain de-energized, and will leave the brake lights on at all times.

Now, on to the troubleshooting:

We know the signal fuse is good because the brake lights are on.

After passing thru coupler #5 the 12V signal power also goes to the windshield drive and horn , so if those two are working then coupler #5 is OK.

That leaves the front brake switch, the rear brake switch, the relay coil, or coupler #2 not having good continuity.

The ABS ECU monitors both the front and rear brake switch signals, so the ABS light would fault for either side of the relay (front switch side or rear switch side).

Since you say that you checked all of the switches and the brake relay already, my money is on the green/yellow wire where it passes thru coupler #2. Coupler #2 is an 8 pin connector in the front cowling area (somewhere) with wires of the following colors in it: Blue/Yellow, Black/Red, Red/Blue, Red/Green, Red/Black, Green/Yellow, Blue, and Black/Yellow. I am not positive of its location (I don't have a 2nd Gen) but maybe someone who has searched and found it can fill you in on that

ionbeam said:

...

The ABS flashing is a separate issue.

Click to expand...

Not so, the ABS controller will error if it sees a permanently-on brake light.

Found this out some time back, written up here (ignore the YCC-S stuff, that's not relevant to th OP).

^^^^^ Oh you Gen II guys (and now Gen III guy). My Gen I and some others that I have followed during EOM and NERDS rides have had their brake lights stuck on without the ABS light flashing. Well, good news for the OP, fixing the brake light may well fix the ABS light flashing too. A two fer one.

First, remove the Hazard Lighting fuse (10 amp) and see if the brake lights go off. This fuse powers the parking lights, license plate light, and turn signals. The brake lights are fed from another fuse but it's possible there is a short circuit somewhere in the rear lighting fixture or its associated wiring which might erroneously power the brake lights from the parking lights circuit.

Next, disconnect the brake light relay from its wiring harness connector. The brake lights should go out with the relay removed. If the lights remain on there's a wiring harness problem between the relay and the brake lights.

Power the relay coil and see if the normally closed contact opens with the coil energized.

Check the coil circuit and the two brake normally closed switches for problems.

Maybe the ground at the end of the coil circuit is open circuited due to problems in the grounding harness. If so, the relay coil can't be energized.

Should be an easy problem to solve once you've accessed the relay.

You guys are awesome! Thanks so much for this info, I have passed it on to the dealer. I'll post the end of the story when it happens.

Thanks again!

PeteyPete

It is a little bit sad when the owners know more about the bike than their dealerships do.

Good luck with your repair

Yes, and back up the line, it's sad when the dealerships know more than the manufacturer. But hey, nobody knows everything, and if we all help each other we can move forward a step.

I've never run into that situation: where a dealership or sales people know more about the product than the manufacturer or designers. Of course, being sales people they may tell you anything, but I think that is more likely than not baloney.

Fred, this NC relay looks like the thing. I and the dealer were both thinking Normally Open relay and switches. You'd think they would know, especially after they had several (long?) conversations with Yamaha. After that was all said and done, I was called last Friday and told it was the rear brake light switch - out of adjustment, and the bike would be ready Wednesday.

It is now Wednesday afternoon, the bike is back together and the ABS light was on. I was told they cleared the previous codes and it was still on, and the battery was a little over 11 volts, probably (duh!) from all the testing. He said the ABS system requires 12.8 volts to operate properly. That threshold sounds kinda high to me, but whatever. The battery is on a charger and now the bike should be ready in the morning. Fingers crossed! Tomorrow is 6 and 1/2 weeks.

PeteyPete said:

Fred, this NC relay looks like the thing. I and the dealer were both thinking Normally Open relay and switches. You'd think they would know, especially after they had several (long?) conversations with Yamaha. After that was all said and done, I was called last Friday and told it was the rear brake light switch - out of adjustment, and the bike would be ready Wednesday.
It is now Wednesday afternoon, the bike is back together and the ABS light was on. I was told they cleared the previous codes and it was still on, and the battery was a little over 11 volts, probably (duh!) from all the testing. He said the ABS system requires 12.8 volts to operate properly. That threshold sounds kinda high to me, but whatever. The battery is on a charger and now the bike should be ready in the morning. Fingers crossed! Tomorrow is 6 and 1/2 weeks.

Click to expand...

ABS light will only go out after riding a short distance (check your Owner's Manual). Haven't they done a test ride to check their "work"?
Over 6 week to find an adjustment of a switch? They should pay you for preventing you from using your bike.

mcatrophy said:

PeteyPete said:

Fred, this NC relay looks like the thing. I and the dealer were both thinking Normally Open relay and switches. You'd think they would know, especially after they had several (long?) conversations with Yamaha. After that was all said and done, I was called last Friday and told it was the rear brake light switch - out of adjustment, and the bike would be ready Wednesday.
It is now Wednesday afternoon, the bike is back together and the ABS light was on. I was told they cleared the previous codes and it was still on, and the battery was a little over 11 volts, probably (duh!) from all the testing. He said the ABS system requires 12.8 volts to operate properly. That threshold sounds kinda high to me, but whatever. The battery is on a charger and now the bike should be ready in the morning. Fingers crossed! Tomorrow is 6 and 1/2 weeks.

Click to expand...

ABS light will only go out after riding a short distance (check your Owner's Manual). Haven't they done a test ride to check their "work"?
Over 6 week to find an adjustment of a switch? They should pay you for preventing you from using your bike.

Click to expand...

Amen to that ... 6 weeks ? The thread mentions (NOT) a common problem ... Probably because the dealer had such a hard time isolating the actual issue. I would submit that this is likely the (MOST) obvious reason (at least is should be to a professional bike mechanic) ...

under an hour with a continuity tester/multimeter should have tracked this down ...

Glad you have it back and are happy but man !!, What a waste of your time in the middle of riding season ....

Just another example of why my bikes never see the inside of a dealership

IF this is on the 2006 listed in his profile, the ABS light should not be on beyond starting it. That ABS thing didn't start until the GENIII bikes. GENII bikes lose the light right after ignition on, unless there's a problem.

Unless something funky is going on, there is still a problem. Don't take it home until you're sure that light is off.

HotRodZilla said:

IF this is on the 2006 listed in his profile, the ABS light should not be on beyond starting it. That ABS thing didn't start until the GENIII bikes. GENII bikes lose the light right after ignition on, unless there's a problem.
Unless something funky is going on, there is still a problem. Don't take it home until you're sure that light is off.

Click to expand...

You mean, leave it at THAT dealer?