ABS light on solid red: 2005, VFR800A

[kwharwood]

VFR Discussion group,

 

My 2005 VFR800A had been sitting in the garage covered for exactly a year. Today, I thought it would be a good time to

change the oil with zero miles on the oil (as I did last 4th of July). I thought my chief concern might be getting it started,

but it started instantly and ran smoothly. However, I notice the ABS light (red, constant, not blinking) is not going off the

way it use when I actually had time to ride it.  Does anyone have an explanation for this ABS light?

 

The bike has not been ridden in one year (tragedy) and everything worked when I put the cover over it in July of 2019.

The bike is extremely well maintained and I am the only one in the garage space.

 

Any and all help greatly appreciated,

Kevin

 

[Grum]

Hi Kevin.

Do you have the Service Manual? If not, you can download it from this site.

- Firstly make sure your Battery is good? Old or dying batteries can cause a whole host of strange issues.

- Make sure your Battery terminals are good and tight.

- Confirm all the ABS fuses are ok.

- Try disconecting the Battery for 10mins then reconnect.

ABS light should go out once speed is above 10 km/h (6mph).

The light constantly ON might mean a stored fault code. You may need to go through the "Retrieval" process as described in the Service Manual.

 

P.S. Kevin you've posted the same thing twice, you need to delete the other one!

[Cogswell]

I think Grum may have put his finger right on it - if you haven't ridden it in a year you may have forgotten how the light cycles off when the ECU sees a certain speed - it will stay on indefinitely if running and left stationary.  It's the only vehicle I've ever seen with that behavior, so is easy to forget. 

[TriumphTraitor]

10 hours ago, Cogswell said:

I think Grum may have put his finger right on it - if you haven't ridden it in a year you may have forgotten how the light cycles off when the ECU sees a certain speed - it will stay on indefinitely if running and left stationary.  It's the only vehicle I've ever seen with that behavior, so is easy to forget. 

It's certainly an odd self diagnostic feature I've seen on every bike with ABS that I've owned/ridden. From what I have been told, in order to keep the ABS module as small and cheap as possible they have a different type of self diagnostics from cars. Idk how true that is though. 

[kwharwood]

Grum, Cogswell, & Triumph Traitor,

 

I greatly appreciate your knowledgeable and informative replies! Yes, I have a Honda VFR shop manual.

I am not an uber mechanical guy, so I will attempt your non-technical advice first and then if needed move to the

more technical recommendations that utilize the shop manual.

 

If I had any idea how to delete my duplicate post, I would certainly do so. Sorry, about that!

 

I really appreciate your help as I have loved this bike for many years now (just get to admire it, but not ride it),

Kevin

 

[kwharwood]

VFR Owners,

I hate to ask such a simplistic question, but I am wondering if it's possible that my solid red, ABS light might

be attributed to the fact that the air pressure in my front or rear tires were extremely low (20 to 25 psi)? The

bike was not ridden and only pushed around in the garage. Currently, my back is not anything near 100%,

so I wanted to ask if there was any possible way this low tire pressure could be the cause of my ABS light.

If not, I will pursue the list of suggestions you have already given me.

Thanks,

Kevin

[Grum]

Hi Kevin.

Do I get this right, are you saying you haven't ridden the bike, you've only pushed it around and wondering why the ABS light is on?

Think you need to ride the bike once your back is ok, and as mentioned the ABS light should go out above 6mph. Service Manual does state that incorrect tire pressure could cause the ABS light to blink.

Good Luck.

[kwharwood]

Grum,

 

Thanks, for your replies as they and other replies have been a 'lifesaver' for me! Yes, the bike had been sitting in my garage

for one year covered, unmoved, and untouched. July 4th, I pushed it closer to the garage door (exhaust fumes) and started it to warm 

the oil prior to this oil change. This is when I noticed the ABS (constant, non-blinking) was not going off as anticipated.

 

Normally, if I put the bike, onto the centerstand,  into 1st gear, and allow the rear tire to exceed 6 mph the ABS normally

goes out immediately. However, when I attempt this process now, the ABS light does not go off. I noticed the tire pressures

were low (20-25 psi), so I aired them up.

 

Wouldn't the bike have to be ridden and both wheels turning for the ECU/computer to notice a discrepancy between the front and rear

wheel speeds to trigger a fault (or ABS light)? Hopefully, you can appreciate my current back situation and the fact that my driveway is extremely steep. 

I would like to do everything possible to keep from riding it (presently) and having to bend over to disconnect and re-connect everything to my battery terminals.

But, if need be and on a "better day," I will be glad to do so!

 

Thanks, for your help and understanding,

Kevin

[Terry]

It does not seem correct to me that the ABS would pass the self-check with just the rear wheel turning but not the front. The manual states that the wheels need to be turning at 6mph or more to trigger the self-check sequence that operates the control motor briefly and then switches the ABS light off. The two ABS circuits are independent I believe so each wheel speed sensor would need to pass the self-check to turn the light off. I think I would relax about this until you get a chance to actually ride the bike. 

[Grum]

Terry you are absolutely correct. The self test function and ABS light OFF at 6mph cannot happen without BOTH wheels turning at that speed.

Also with respect to tire pressures. The ABS is sensitive enough to detect changes to the tire circumference at low pressures which could cause the ABS light to blink. Might be a good way of detecting a puncture as well!

 

Good luck with that bad back, hope you're up to riding before your good weather runs out.

Hopefully, once riding, you might find there is nothing wrong with your ABS.

Cheers and Good Luck.

[Terry]

Graeme is that correct about the tyre pressures? I know that is how the TPS system works in VW and Skoda cars, and there is a reset procedure when you change the tyre pressures to "educate" the wheel speed monitor about what "normal" should feel like i.e. their speeds relative to each other. But do simple two-channel bike ABS systems look across the channels to determine relative speeds? I imagine some of the later systems that include traction control (so wheel spin can be determined) might but my guess is the early Honda systems possibly don't. I'm speaking from a point of ignorance here BTW. 

 

Sorry to hear about Vic being cut off from the rest of Oz. I guess now you know how it feels to be a Tasmanian! 

[Grum]

3 hours ago, Terry said:

Graeme is that correct about the tyre pressures? I know that is how the TPS system works in VW and Skoda cars, and there is a reset procedure when you change the tyre pressures to "educate" the wheel speed monitor about what "normal" should feel like i.e. their speeds relative to each other. But do simple two-channel bike ABS systems look across the channels to determine relative speeds? I imagine some of the later systems that include traction control (so wheel spin can be determined) might but my guess is the early Honda systems possibly don't. I'm speaking from a point of ignorance here BTW. 

 

Sorry to hear about Vic being cut off from the rest of Oz. I guess now you know how it feels to be a Tasmanian! 

Hi Terry.

I admit to being no ABS expert either. But based on the Service Manual it states "The ABS indicator might blink with incorrect tire pressure", the only way the ABS could detect this is the subtle changes to tire circumference thus producing a slight difference in rotational speed between the two wheels.

The system must be checking or comparing both channels and is no doubt the reason that just spinning up the rear wheel to above 6mph does not satisfy its self test to turn the light off.

I don't think you could call the 6gen ABS "just a simple two-channel bike ABS system" it's possibly as complex as your ECM, ABS having sensor inputs, motor controller outputs, failsafe, CPU, diagnostics etc.

 

On the 8gen, the front and rear wheel sensors are used by three separate systems. ABS, Traction Control, and Turn Signal Auto Cancelling, and also the rear wheel sensor is the main Speedo info (unlike the 6 gen speed sensor that's mounted onto the drive sprocket bolt head).

Traction Control just seems to be an extension of ABS and draws heavily on Front to Rear speed differential information for ECM torque control.

 

Thanks for your concern. STUFF IT as I write, just heard we are back to lockdown situation! We really are starting to see a classic runaway effect happening that might be getting out of hand. An example of how easy that restriction removals and quarantine violations can bring on a second wave. I am Serioulsy concerned for our American friends as their infection rates are extraordinary! Great job that NZ appear to have isolated the bug completely.

 

To ALL out there, PLEASE Keep Safe and be vigilant about hand cleanliness and social distancing, it might just save your life!

Cheers.

 

[raYzerman]

Thanks, Grum... similar sentiment here.

All ABS bikes I have had require seeing both signals when moving to turn the ABS light off (assuming everything is working correctly).  Completely normal.  Go ride and tell us all about it.