ABS Light stays on

[CraigRegs]

I'm working toward the edge of my abilities on this problem and could use some insight.

Symptom: 2007 A, ABS dash light comes on steady after a few minutes of riding. Shutting the bike off and restarting shuts the light off for only a minute or so. The problem first presented a month or so ago and was intermittent, and became increasingly persistent. Now the light's on within a couple of minutes of getting underway and stays on, steady.

Things I've checked:

ABS Fuse: ok

I performed both ABS hydraulic tests as outlined on page 4-60 of the FSM. ABS performed as described in the manual. Error codes: 11 - 15 - 24 - 25 - 26 - 41. I'm assuming this is a complete history of errors, not just errors related to the ABS light issue. FSM says codes are interpreted thusly:

• 11: Front wheel sensor signal is not received properly
• 15: No continuity in the front or rear wheel sensor circuits
• 24: Brake light is defective (I replaced the light several months ago and both work properly with lever and pedal application.)
• 25: No signal is received from the front wheel sensor when the vehicle starts moving.
• 26: Incorrect signal from the front (13/26) wheel sensor is detected. (Not sure how to read this. Does this code apply if I didn't get a "13", but only a "26"?)
• 41: Front wheel will not recover from the locking tendency even though the signal is continuously transmitted from the ABS ECU to release the hydraulic pressure.

After this test, I cleared the codes and performed the diagnosis a second time. Only code returned is 11.

I checked the front wheel sensor resistance per 4-20 of FSM. Reading of 1.38, within specs of 1.2-1.8.

Checked ABS motor relay per 8-223 of FSM. Reading of 99 ohms, within specs of 50-150.

Per the troubleshooting chart on 8-135, I'm working through step C-6, The ABS warning light remains on. I'm to the point now where I guess I need to start digging into the ECU couplers, wire harness, etc. My first question: Where the hell is the ECU? Is it that finned metal box in front of the rear shock and below the seat tray? (Told you I'm at the edge of my abilities.) If so, do you access by removing the tray below the seat?

Any other insights or tips would be greatly appreciated.

 

[JamesK]

The ECU is located near/next to the airbox, directly below the rider's seat. You'll see a big connector plugged into it, so it's hard to miss it once you know where to look. The "finned" thinggie is the Regulator, so totally unrelated to your ABS problem.

Based on the description of your testing it sounds like the ABS is working, despite the warning light being on, at least it passes the FSM tests. I think it is possible to trigger the ABS light if there is a wrong kind of load/tap running off of any of the brake wires. Have you connected any after market gadgets to the brake wires, e.g. brake flasher or even an extra brake light, depending on which kind of extra brake light can trigger the ABS light.

I would also re-do the front ABS sensor test while pulling and giggling the sensor wire as you mentioned this problem was previously intermittent...

If you're skilled/confident enough in your riding abilities you could always do a live test in some empty parking lot. The rear is no problem to do, and the front should be easy enough if you are confident in being able to release the front brake once the front wheel locks up. If the bike passed the real ABS test on both wheels than the light is not much of a concern and can be "fixed" with a small piece of black electrical tape

 

[Mihalis fjr]

Perhaps a corroded front or a rear wheel sensor coupler..?Also pull out the two sensors and have a look at them and their wires..

 

[Fred W]

Some of those errors are probably old / stale. Clear all the errors and see what new ones pop up. Then you can work on those. I suspect one of the sensors has been acting up.

 

[CraigRegs]

Think I may have found the source of the problem. When I initially pulled the front sensor, it had collected a significant amount of metal filings. Didn't think too much of it until today when I was changing the front tire and noticed the bearing on that side of the wheel was falling apart. At least a couple of ball bearings were missing and there were plenty of shavings from the bearing case collecting in the sensor housing. New bearings and seals on order. Hopefully that clears up the ABS light issue...and I feel fortunate the bearing lasted until I started this round of maintenance.

 

[Mihalis fjr]

Probably this was the problem!Let us know if your problem has solved..

 

[rPGoatBoy]

Think I may have found the source of the problem. When I initially pulled the front sensor, it had collected a significant amount of metal filings. Didn't think too much of it until today when I was changing the front tire and noticed the bearing on that side of the wheel was falling apart. At least a couple of ball bearings were missing and there were plenty of shavings from the bearing case collecting in the sensor housing. New bearings and seals on order. Hopefully that clears up the ABS light issue...and I feel fortunate the bearing lasted until I started this round of maintenance.

Um...pictures please? This is the kind of thing that's disconcerting for those of us who ride over the ton on occasion.

 

[CraigRegs]

Think I may have found the source of the problem. When I initially pulled the front sensor, it had collected a significant amount of metal filings. Didn't think too much of it until today when I was changing the front tire and noticed the bearing on that side of the wheel was falling apart. At least a couple of ball bearings were missing and there were plenty of shavings from the bearing case collecting in the sensor housing. New bearings and seals on order. Hopefully that clears up the ABS light issue...and I feel fortunate the bearing lasted until I started this round of maintenance.

Um...pictures please? This is the kind of thing that's disconcerting for those of us who ride over the ton on occasion.

Wish I had taken photos. The filings were just fine shavings sticking to the tip of the magnet of the sensor, like a little goatee beard (how's that for a picture?). The bearing damage was obvious. I could see the ball bearings (which you shouldn't be able to see), and a couple were missing. And disconcerting: I just got back from a 1300 mile trip through WY/CO with a few episodes above the ton. Someone's watching over me...

Final resolution: Replacing the front bearings has solved the issue.