Can Removing the ABS System Damage the ECU?

[Dirk_S]

Question for all of the "don't remove/disable it, you Luddite!" guys: Wouldn't the ABS go into "convulsions" when it doesn't see the signal(s) it expects from the tone rings on the (not original diameter) wheels? Wouldn't it need to be factory calibrated for the 21" front wheel in order work properly?

Good point. Although one *should* recalibrate the traction control system when fitting new wheels, I can’t A) recall if that’s also needed for the ABS, and B) if the recalibration is prepared for such a drastic change in diameter. Maybe I ought to finally fit this speed sensor back on sooner than later just to even find that out.

[DoubleGuzzi]

The manuals state that the ABS system shuts off in the event of a malfunction and allows the brakes to operate conventionally.

Presumably the warning light blinks constantly and there's a wee bit of black insulating tape, to stop it distracting you. 

[Dr. Enzo Toma]

If you're worried about the complexity of things and are dead set on removing the ABS, consider also removing the ECU and going with a simple aftermarket system like a MicroSquirt or MegaSquirt that is more open instead of being a black box.

[Kev m]

If you're worried about the complexity of things and are dead set on removing the ABS, consider also removing the ECU and going with a simple aftermarket system like a MicroSquirt or MegaSquirt that is more open instead of being a black box.

You know that would also require the replacement of the throttle body and a number of integral sensors on a 1TB smallblock V7 (before the new 25 models). Talk about adding complexity.

[n3303j]

Carbs and an electronic ignition that keys off the crankshaft and most of the complexity is gone

[rocker59]

Wouldn't the ABS go into "convulsions" when it doesn't see the signal(s) it expects from the tone rings on the (not original diameter) wheels? Wouldn't it need to be factory calibrated for the 21" front wheel in order work properly?

No.  ABS doesn't know what the wheel diameter is.  It is measuring changes in speed, not differences in wheel/tire diameter.  The system calibrates itself each time you start up and roll away.

[Dirk_S]

You know that would also require the replacement of the throttle body and a number of integral sensors on a 1TB smallblock V7 (before the new 25 models). Talk about adding complexity.

Adding complexity to the job, yes, but simplifying the bike. I’m not adverse to getting my hands dirty and putting in some time for a satisfying end product.

Like, when it was mentioned “do I want to go through all the time to remove the ABS pipes, module, make new hoses”, etc. Easy stuff. I’m single. I have the time.

[Kev m]

Adding complexity to the job, yes, but simplifying the bike. I’m not adverse to getting my hands dirty and putting in some time for a satisfying end product.

Like, when it was mentioned “do I want to go through all the time to remove the ABS pipes, module, make new hoses”, etc. Easy stuff. I’m single. I have the time.

How would that simplify the bike?

You would be replacing a single component with a half dozen or more, including a more sophisticated throttle body.

No.  ABS doesn't know what the wheel diameter is.  It is measuring changes in speed, not differences in wheel/tire diameter.  The system calibrates itself each time you start up and roll away.

I believe you are mistaken.

The ABS/TC system runs a self-test after each start up and speed reaches a certain point. It internally checks that it can pulse the modulator servos and that it is getting speed signals. But it doesn't calibrate for differences between the wheels. That action requires a manual signal to the module to actively measure and adjust its parameters which is supposed to be done after tire replacement.

[Perazzimx14]

How would that simplify the bike?

You would be replacing a single component with a half dozen or more, including a more sophisticated throttle body.


I believe you are mistaken.

The ABS/TC system runs a self-test after each start up and speed reaches a certain point. It internally checks that it can pulse the modulator servos and that it is getting speed signals. But it doesn't calibrate for differences between the wheels. That action requires a manual signal to the module to actively measure and adjust it's parameters which is supposed to be done after tire replacement.

Isn't the ABS looking at the tone ring and not the wheel diameter? I know on my R1200GS that came factory with a 19" front wheel I can put on a 17" front wheel from a R1200RT/R and and long as I have the right tone ring the bikes ABS, speedo or ECU is obvious to the change in wheel diameter. The tone ring is the constant not the wheel/tire.

[n3303j]

Thought ABS looked for an abnormal difference wheel rotation to cue that one wheel lost traction? Therefore it required a base differential in memory?

[Kev m]

Isn't the ABS looking at the tone ring and not the wheel diameter? I know on my R1200GS that came factory with a 19" front wheel I can put on a 17" front wheel from a R1200RT/R and and long as I have the right tone ring the bikes ABS, speedo or ECU is obvious to the change in wheel diameter. The tone ring is the constant not the wheel/tire.

Yes tone ring, but it's relation to actual distance the tire covers varies with tire diameter. Just like changing the size of your Jeep or truck tires changes the relationship between the driveline and how far you've traveled. So it memorizes tiny differences between what it expects to see at each tone ring before thinking one of them is starting to slide.

[Dirk_S]

Yes tone ring, but it's relation to actual distance the tire covers varies with tire diameter. Just like changing the size of your Jeep or truck tires changes the relationship between the driveline and how far you've traveled. So it memorizes tiny differences between what it expects to see at each tone ring before thinking one of them is starting to slide.

Revisiting the owners manual, I remembered the recalibration was needed for the traction control, which is mentioned in the literature. However, recalibration is not stated in the ABS section, just notes that the system recognizes lockups:

ABS system (02_36, 02_37, 02_38)
The vehicle is equipped with a locking «ABS» system on the rear and front wheel.

The ABS system is a hydraulic - electronic device that limits the pressure within the braking circuit when a sensor located on the wheels detects the tendency to lock up, increasing the stability of the vehicle in braking with respect to a traditional braking system in order to decrease the risk of falling.

[n3303j]

Unless there is a really good inertial sensor or GPS in the equation the ABS needs the "other wheel" as a reference to its rotational speed.

Not sure what happens if you could lock both in exact unison?

[Moparnut72]

Now that's a good question. It is now running through my brain searching for an answer. 
kk

[Dirk_S]

More from the service manual, if it’s at all helpful:

When the sensors (3) detect a significant speed difference between the rear and the front wheels (for example, when rearing up on the back wheel), the ABS system could take this as a dangerous situation.

In this case, two things may occur:

• The ABS system intervenes by releasing pressure from the calliper until the wheel turns again at the same speed of the other wheel. It is not possible to brake for an instant.
• if the speed difference lasts long, the system may detect an error and deactivate the ABS system. As a consequence, the system works like any regular braking system.

[Kev m]

Revisiting the owners manual, I remembered the recalibration was needed for the traction control, which is mentioned in the literature. However, recalibration is not stated in the ABS section, just notes that the system recognizes lockups:

They are related systems sharing data.

Again a self-test isn't a recalibration or vice versa.

[rocker59]

I believe you are mistaken.

The ABS/TC system runs a self-test after each start up and speed reaches a certain point. It internally checks that it can pulse the modulator servos and that it is getting speed signals. But it doesn't calibrate for differences between the wheels. That action requires a manual signal to the module to actively measure and adjust it's parameters which is supposed to be done after tire replacement.

Learn something new everyday.  I've got some reading to do. 

[Kiwi_Roy]

Just pull the 20 Amp fuse (49) if you must, I can't imagine why it would cause the ECU to fry.
https://www.thisoldtractor.com/guzzi007/schematics/2019_V7_III_E4_Anniversary_-_Racer_-_Special.gif
Like they say its your bike, you are entitled to spoil it.

[Dirk_S]

Just pull the 20 Amp fuse (49) if you must, I can't imagine why it would cause the ECU to fry.
https://www.thisoldtractor.com/guzzi007/schematics/2019_V7_III_E4_Anniversary_-_Racer_-_Special.gif
Like they say its your bike, you are entitled to spoil it.

As with the V7 II, pulling the ABS fuse disconnects the dash as well. No speedo, odo, tacho. The solution is to either pull the front wheel sensor off every time I desire no ABS, install an inline on/off switch, or remove the ABS module completely.

[Perazzimx14]

As with the V7 II, pulling the ABS fuse disconnects the dash as well. No speedo, odo, tacho. The solution is to either pull the front wheel sensor off every time I desire no ABS, install an inline on/off switch, or remove the ABS module completely.

Assuming the front ABS sensor is two wire installing an inline switch should not be too difficult. I have been using these handlebar switches for a while now and they make for a clean factory-esk installation, they are durable and reasonably priced at under $10. The come in on/off or on/off/on. The on/off/on version works a treat when installing dual color LED running lights. Flip the switch one way lights are white flip the other way lights are amber or in the middle position the lights are off.

[Dirk_S]

I'm guessing the ABS sensor is two wire and should be easy to install an inline o/off switch.

I have been using these switches off the Jungle for a little while now and am very happy with the durability and clean look. They also come in a on/off/on version and work a treat for dual color LED running lights.

I actually have the same switch sitting in a bin waiting to be installed should I finally get around to doing the inline switch job.

[aklawok]

 Wow, so many varied opinions!
I like the idea of a minimalist dual sport v7III ( this coming from someone who rides a CalVin in quite off-road conditions) I feel that there would be so many more capable bikes for this. Loosing a pound or two is nice but wouldn't you want to go all the way? Toss all the "dead weight" so to speak? All the lights fenders gauge panel, etc....?
As an aside, going to carbs is ok for an OHV. But would be an illegal modification of an imision control (as would non cat pipes...but not many care) depending on your state I.M. test, you may never be able to sell it, or register it as a road bike again.

[Perazzimx14]

Wow, so many varied opinions!
I like the idea of a minimalist dual sport v7III ( this coming from someone who rides a CalVin in quite off-road conditions) I feel that there would be so many more capable bikes for this. Loosing a pound or two is nice but wouldn't you want to go all the way? Toss all the "dead weight" so to speak? All the lights fenders gauge panel, etc....?
As an aside, going to carbs is ok for an OHV. But would be an illegal modification of an imision control (as would non cat pipes...but not many care) depending on your state I.M. test, you may never be able to sell it, or register it as a road bike again.

Easier to put a Mono Guzzi sticker on a DRZ400/DR650 and you'll have a minimalist bike that is road legal and 100 lbs lighter than the V7.

[Dirk_S]

Wow, so many varied opinions!
I like the idea of a minimalist dual sport v7III ( this coming from someone who rides a CalVin in quite off-road conditions) I feel that there would be so many more capable bikes for this. Loosing a pound or two is nice but wouldn't you want to go all the way? Toss all the "dead weight" so to speak? All the lights fenders gauge panel, etc....?
As an aside, going to carbs is ok for an OHV. But would be an illegal modification of an imision control (as would non cat pipes...but not many care) depending on your state I.M. test, you may never be able to sell it, or register it as a road bike again.

I’m not looking to create a dirtbike or lightweight enduro. But trimming some fat is a worthy endeavor for off-pavement/off-road. I still need lights and mudguards for street legality, and I’m already fairly minimalist in those areas. No need to ‘go all in’. The current KLR and the old R100 GS weigh about as much as this bike. A few pounds less is noticeable, especially as I pack on other weight like luggage and accessories that I want to take.

[Dukedesmo]

Surely a bike ABS only needs to see rotation or not (wheel locking), it cares not for the exact speed of rotation and as there's only 1 wheel per 'axle' it doesn't need the reference from the other wheel like a car would, If so then wheel size is irrelevant? Unless, the ABS sensor doubles up as the speed sensor, in which case then changing the ring or recalibrating the system would be required?


Traction control on the other hand would, presumably need reference to and from the speed of the front wheel to know by how much the rear wheel is spinning.



That said, I don't know any of this this as a fact and I don't have an ABS/TC equipped bike so might be talking complete bollox but it seems logical to me.


As for removing it, well I wouldn't do it but I don't see how it would damage the ECU, though something would probably need disabling to prevent warnings etc.

[Tom H]

As mentioned, TC needs to be calibrated to the set of tires.

If your just putting new tires on of the same size, then it does not NEED to be done. If your changing from a let's say 100/90 to a 100/100 or a 19" to a 21" wheel then I think it would be a good idea.

I helped work on a V7III with TC that would cough and cut out when tried to get moving, idled just fine and would rev just fine until you tried to move. Looked at everything, found nothing. Then we noticed the back tire was rather low on air. Filled tire and all the issues were gone. The TC was seeing the low tire as the wheel slipping since it didn't match the front wheel speed and was kicking on. How simple a fix??

Tom

[Kiwi_Roy]

As with the V7 II, pulling the ABS fuse disconnects the dash as well. No speedo, odo, tacho. The solution is to either pull the front wheel sensor off every time I desire no ABS, install an inline on/off switch, or remove the ABS module completely.

Thats not what the schematic shows (Do I have the correct schematic?) It shows Fuse G 20 Amp feeds only the ABS unit goodness knows where this fuse is hidden.
You could also switch the wire going to terminal 18 of the ABS unit if you can't find the fuse.
https://www.thisoldtractor.com/guzzi007/schematics/2019_V7_III_E4_Anniversary_-_Racer_-_Special.gif
The Dash is fed from switched 5 Amp fuse D.
You might also check out the +Key input to terminal 4 of the ABS unit, that might disable it also.

Disabling the ABS will also disable traction control, I have only experienced that cutting in once accelerating on a slippery wooden bridge.

Ooops, Sorry Dirk, both the wheel sensors are wired to the ABS box, that means the speedometer won't work if you pull the fuse, because the ABS communicates with the Dash and ECU via the twisted Canbus interface, I wonder if switching the wire to terminal 4 will also disable Canbus.
You might just have to rethink removal of ABS unless you can do it hydraulically e.g. swapping brake lines.
Another option switch just the front speed sensor, the speedometer usually uses the rear sensor I think, that should disable the ABS but it won't save much weight or simplify anything.
I will follow this thread with interest to see what you find.

[steven c]

When i had my VStrom I put in a switch to turn off the ABS in loose dirt, gravel. It was easy to do on that bike.

[Kiwi_Roy]

Well. I thought  would do as Dirk did and remove the front speed Sensor, tucked it in behind the brake line.
So then I got a pair of annoying lights Winking at me, but heres the part I don't understand.
The bike was powerless would barely do 30 kph at full throttle, I felt like I was going to get run over.
I suspect if the ABS is showing error codes the ECU plays it safe by dialing back the power.
Before I got a mile down the road I pulled over and bolted the sensor back restoring the good power as before.
You are welcome to take the ABS off but I know what I'm going to do,
if it ain't broke, don't fix it.
Roy

[TN Mark]

An airbag vest is nice to have. How many of y’all wear that? Full leg armor. A motorcycle with gyroscopic ability to keep you upright. Heck— Four wheels and a cage around you.

Less stuff for the computer to crap out on. This is my go-everywhere bike, and I’d prefer it lean toward the simpler R80 G/S way of living rather than the R1300 GS lifestyle.

I’m even considering going carbureted with this bike.

Sell the V7 III and get a Convert or a G5.
No electronics to worry you that way.