How to Reset the ABS on a K12RS

[lskbike]

Last Saturday, I lowsided my 98 K12RS. I lost the rear wheel on slick pavement around a curve at a very low speed. It was a "perfect" Dakar Taxi. Now it is not so "perfect"! I'm OK thanks to an Aerostitch suit. Unfortunately the bike is scratched up a bit.

 

My problem is that apparently the rear wheel stopped rotating when it lost traction and the front wheel continued to rotate which apparently caused the ABS system to default. The ABS lights now flash on and off...rotating one then the other. The ABS will not reset!

 

Will I need to take it to a dealer (closest one is one hour away!) to have the ABS reset or can someone on this list advise me how to do it? (lskbike@yahoo.com)

 

Any help would be appreciated.

 

Thanks

 

LSKbike

Southeastern Indiana

[rdfrantz]

I don't know of a "Magic Formula", as with the RT of "Pull fuse #29, squeeze the front handbrake, then deploy the side stand."

 

However, I know you won't hurt anything by removing the battery ground lead for the minute it might take the ABS to reset.

 

I'm not certain your estimation of why you have an ABS fault is on the mark. More likely the opposite may have occurred where the rear wheel overspeeded the front. But even that may not be the cause. If the fault will not clear by removing the battery cable, do check for damage to the sensor rings and pick-up, and I'd wish you'd head for the dealer.

 

Best wishes.

[Aluminum_Butt]

I'm not certain your estimation of why you have an ABS fault is on the mark

[Hijack] I was wondering the same thing. I've never assumed there was some link between the front and rear, except for whatever was happening at that moment - big difference in wheel speed = problem. But it seems like once the wheels quit spinning, that goes away - especially once the ignition has been turned off and back on. How could this be causing an ABS fault now? Any of you techies willing to explain how this works? I'd like to understand the system better. [/Hijack]

[bmwmick]

Dawg,

That was a common failure mode on the earlier ABS-I bikes. I caused a fault on my '93 K1100LT about a month after I got it. I tried bump starting it and slid the rear tire. That action set a fault that I had to get reset at the dealer. Now after all these years we know how to read out the faults and reset the ABS-I control unit 'most of the time'.

The ABS-II control units were much more tolerant of this mismatched wheel speed fault. I've never had a fault on my '96 R1100RT (ABS-II) that wasn't low voltage related.

 

Mick

[lskbike]

Prior to the posting of my original email about my low side and the ABS fault, I had actually checked the bike over very carefully. It was a very minor spill! There was no damage to anything other than the side panel and left bag. After the event, the flashing ABS lights would not go off when the bike was underway. Also, prior to posting my question, I had already disconnected the ground wire from the battery and left it disconnected overnight to see if that would reset the ABS. It did not.

 

The reason I asked if anyone knew how to reset the ABS on a K12RS is because two years ago the same thing happened to a friend of mine. He took his bike to a dealer. The mechanic told him something along the lines that... the flashing ABS warning lights indicated the system had defaulted probably because of his accident. The mechanic stated he had reset the ABS and all was fine. The mechanic explained that the way an ABS system worked was that a computer monitored the rotating wheels. When brakes are applied and one wheel rapidly starts to rotate slower than the other, indicating the start of brake lockup, the computer senses that and automatically releases the brakes on the slowing wheel and keeps it from locking up and sliding. This happens several times a second until the shortest stopping distance possible is achieved.

 

The mechanic continued to explain that what must have happened when the bike was on its side with the ignition on was that the front tire had stopped rotating but the rear tire was probably rotating since the bike was still running at idle. Since the front wheel was not rotating and the rear wheel was, he stated the computer tried to continuously monitor the brake system and tried to control the front wheel's slide. It will apparently cycle this way many times for a few seconds with no resolution. In this case, then the computer defaults, (shuts off!) This is why the ABS lights were flashing indicating the "default" mode meaning the ABS is not working. I understood him to say that he only had to reset the ABS to get it working and it was no big deal.

 

This seemed like a reasonable explanation to me! If anyone knows for sure I would definitely like to hear from them one way or the other! The dealership that provided this information to my friend is now closed but I plan on calling another to check into the ABS situation.

 

Thanks!

 

LSKbike

Southeastern Indiana

[Shaun]

I don't know for sure ... but the mechanics explanation seems reasonable to me. However, I'm a bit surprised that the ABS controller won't reset especially via battery disconnect and that it takes a dealers magic touch.

 

In my mind the persistent warning lights indicate that something is still not right in one, or both, of the ABS circuits. No matter how minor the incident, strange things can happen. In any case a dealer should be able to settle the matter in short order.

[bmwmick]

The mechanic continued to explain that what must have happened when the bike was on its side with the ignition on was that the front tire had stopped rotating but the rear tire was probably rotating since the bike was still running at idle. Since the front wheel was not rotating and the rear wheel was, he stated the computer tried to continuously monitor the brake system and tried to control the front wheel's slide. It will apparently cycle this way many times for a few seconds with no resolution. In this case, then the computer defaults, (shuts off!) This is why the ABS lights were flashing indicating the "default" mode meaning the ABS is not working. I understood him to say that he only had to reset the ABS to get it working and it was no big deal.

 

This seemed like a reasonable explanation to me! If anyone knows for sure I would definitely like to hear from them one way or the other! The dealership that provided this information to my friend is now closed but I plan on calling another to check into the ABS situation.

 

Yes,

But it's not a "DEFAULT" mode, it's the FAULT mode.

Since the ABS control unit could not control the imagined sliding of the front wheel, it sets a fault. The DEFAULT condition after a fault like that is NO ABS and they want the rider to know that. The error condition for this failure is latched and can only be reset by grounding the correct pins on the ABS control unit. Any dealer with a GT-1 diagnostic system can hook it up to your bike (round diagnostic connector) and test/reset the condition. They will probably charge you at least 1/2 hour at their going rate to do this.

The earlier ABS-II bikes had a momentary (ABS Cancel) switch on the dash that could be used to reset the 'latched' fault. You do not have that switch. I have spent a good bit of time going through the K12RS(ABS-II) wiring diagrams at my local dealer but I could NOT find a wire from the round diagnostic connector to pin #21 on the ABS control unit. It HAS to be there, otherwise they could not clear the faults with their GT-1 connected only to that connector.

The ABS cancel switch supplies a Ground signal on pin #21 of the ABS control unit. When the ABS control unit FAULTS like yours did, we can just depress that momentary switch to turn off the flashing of the ABS lights (this condition gets reset periodically by the self-test).

To reset my ABS-II, I have to attach a ground jumper on pin #2 of the handy little ABS Diagnostic connector (this is a 3-pin connector that you do not have) then turn on the ignition and hold the ABS cancel button down for 8-30 seconds. If you could access pin #21 on your ABS connector, you 'should' be able to ground that pin for 8-30 seconds while at the same time you have a ground jumper attached to pin #2 on your round diagnostic connector (brown wire with a blue stripe).

Here is a good place to do some reading: http://www.largiader.com/abs/absfault.html

 

Mick

[lskbike]

Thanks everyone for the input...especially you Mick!

 

If I can't find the correct pins and correct the fault, I still can relax knowing that a dealer should be able to do it next spring!

 

Happy Trails all! Have an excellent weekend!

 

LSKbike

Southeastern Indiana

02 KLR650 - GI JOE (The Smile Maker!)

98 K1200RS - Dakar Taxi! (Only slightly damaged!)

97 Ducati - 900SS/SP - Yellow Duck! (Daffy???)

 

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