ABS ECU Faults

[scopeusa]

I had an ABS problem back in 2016 on my 2012 XT1200 when I kept getting fault 63, the front brake master cylinder pressure sensor come up. I tried everything and did get it to reset once which lasted about 30 miles. One odd thing was if I left the bike standing for a week or more the ABS light would go off and reappear anything after a few hundred yards to five miles. Because I had exhausted my options and being on a Caribbean Island I had no access to a dealer I decided I would ride without ABS and get around to fixing it. Well time flies and that was 18 months ago. Now not only the ABS light is on but the engine light turned on the traction control and the speedometer has quit.
I bit the bullet and purchased a new ABS controller. The install is not really difficult and the bleed seemed quite straight forward. The difficult or most treacherous part being the ABS ECU connector housed in a very tight space but with the hydraulic unit out of the mudguard section you can see exactly what you are doing and you have every confidence that the connectors are mating and aligned perfectly.
I connected the ABS test coupler and to my dismay the ABS light gave me two faults, 16 and 33. 16 being the rear wheel sensor, which did not surprise me as I guessed that may have been what caused the traction/control and speedometer fault; however 33 was not expected, it comes up as ABS motor defective or no power supplied to the ABS motor! I checked all three fuses, ABS motor, ABS Solenoid and ABS ECU and they are all good. I have measured ABS ECU voltage at the pins on the ABS ECU plug as detailed on page 8-130 of the Yamaha manual (2010) Positive BR/W Brown/White (1) and Negative B Black (2) and record 13.4 volts (lithium battery). The Brown/White shows up on my XT(1200Z(Z) 2010 as the going to the ABS solenoid fuse. I have just realized that that is not the ABS motor supply!
Does anyone have a full pin out of the ABS ECU connector? I am assuming the rear wheel sensor is responsible for the speedometer? Is there any way to test a wheel sensor? I have tried resetting the fault codes but I guess you cannot reset a fault code that is still there. I assume that the ABS fault codes are held on the ABS ECU and not the main ECU?
I guess it’s back to probing out the harness although everything I have checked/inspected looks as if it came off the production line yesterday not a hint of corrosion. Engine ground, frame grounds all look excellent.
Any help suggestions would be greatly appreciated. As far as I know not many bikes suffer from ABS Hydraulic unit failures. Cheers

 

[2daMax]

http://www.yamahasupertenere.com/index.php?topic=9361.0

Somewhat the front ABS sensor also will also cause the TCS to have problems. Check the cables for damage, if you have not done it.

 

[scopeusa]

After tracing out the abs motor circuit I discovered that whilst the fuse is good the connection between the hot terminal of the started solenoid module, which also routes the 30 amp hydraulic ABS motor fuse is bad. This is buried within the solenoid body. I made up a temporary bypass fused connection to the harness connector at the solenoid and turned on the main switch. I went into reset mode with the ABS test coupler installed and bingo the bad hyd motor/no power fault 33 disappeared. Now its just tracing out fault 16 which states a short circuit on the rear wheel sensor circuit. I disconnected the sensor at the connector under the seat and tried to clear the fault but it would not clear. I assumed that if you removed the short and the sensor was not installed it would register a different fault.

I will try and sort the sensor today although without a replacement on hand the best that I can hope for is to clear the short circuit and register another sensor fault. If its just the sensor and a new solenoid then the parts should not be much. I can put the bike back on the road and just wait two weeks for the parts to arrive. Fingers crossed, I guess there is no way to test a wheel sensor? Thanks

 

[stutrump]

Thanks for keeping us updated. Always interesting to see how these problems resolve. Good luck with the rear wheel sensor

 

[Thrasherg]

Could it mean the short in the rear sensor is still in the harness, between where you disconnected the sensor and the ecu? If the short was in the sensor and you unplugged the sensor and reset the ecu I would expect to see a different error message, but as you still see a short fault, I would suspect you have damage to your wiring loom that is shorting the rear sensor. I would still be trying to follow the wiring from the disconnected sensor plug back to the ecu and see if you can spot any obvious signs of damage. If not I hate to say it, but I would try cutting the wire that goes to the sensor, very close to the ecu (so you know there is no short and see if you still get the same error message after resetting the ecu again. if you do, then you know it’s an old error code that won’t clear until a new sensor is connected, but if the error does clear then you know for sure you have a short in your wiring harness between the ecu and the rear sensor plug that you disconnected. You would have to resolder the cut wire afterwards, but it would seem to be a good way to verify if you do have a short in the wiring loom or not. Only do this if you trust your soldering skills as the cut wire could be a possible issue in a few years time if the joint is not well done.

Gary

 

[TheBeast]

@scopeusa, I am also having “fault 63” with the exact same symptoms you described (see my reaction in your initial post http://www.yamahasupertenere.com/index.php?topic=18907.msg322125;topicseen#msg322125) so I would very much like to hear from you whether replacing the ABS unit made this error go away. If so, it means that the “front brake master cylinder pressure sensor” is located inside the ABS unit. Right?

 

[scopeusa]

Well the confusion was that fault 16 stated that it was a short circuit. When I turned the page of the manual I discovered the answer......... I checked the loom between the rear wheel sensor connector and the ABS ECU and it all metered out OK checking continuity and no short or ground faults. I then tried to clear what is shown as a short via the reset and no luck. I then turned over the page of the manual and realized that there was a follow on to fault code 16. It states that if you have metered out the wiring and there is no short that the fault requires a new rear wheel sensor and will only reset after it is installed. The wheel sensor is perfectly clean and the wiring undamaged. I have ordered a new starter solenoid and rear wheel sensor from Yamaha Sports Plaza. This will take around two to three weeks to get to the islands.

As to our friend who has fault 63 showing up I apologize for not answering his original post. I have been off the radar. The answer is that yes I replaced the ABS ECU and it cleared the front brake sensor fault immediately. To double check I unplugged the new unit and re plugged the old unit in. Sorry to be the bearer of bad news but the old ECU was working perfectly, it brought up the two faults that I had on the new unit, no power to the ABS motor and the short circuit on the rear sensor PLUS the fault code 63 front brake pressure sensor. Reverting to the new unit the fault code 63 cleared the first it was reset. When I first inquired there was zero stock of the ABS unit in the USA. There were only five in existence in Japan. Mine was special ordered in from Yamaha Sports Plaza. The cost from the dealer where I have a home in Florida was somewhere in the region of $1,300 I paid $900. I have been riding my bike without ABS for sometime. It was bugging the hell out of me so when it came time to change the rubber It stripped it down and used the opportunity to do a bunch of jobs that I was going to get around to. I will let you know the outcome when the wheel sensor arrives.

I would be interested to know if anyone out there has a rear brake light flasher installed. I have one on mine but I am wondering if the pulsing current could affect the ECU as I believe the brake light wiring feeds to the ABS ECU. Just a thought....

 

[Checkswrecks]

I separately tried an LED flasher on my 2012 and then LED tail light bulbs, and ended up back with stock. I didn't think to see if the ABS was functioning or not but both illuminated the light. Should have known better, as the bulbs (not the flasher) were from trying going LED on a 2007 FJR and having the same result.


Not saying that LED won't work, just that the versions I tried didn't play well with those two bikes. Since the bulbs I used would now be 10+ years old technology and the flasher 5+ years, maybe they were different and not as good as current ones.

 

[TheBeast]

<snip>
As to our friend who has fault 63 showing up I apologize for not answering his original post. I have been off the radar. The answer is that yes I replaced the ABS ECU and it cleared the front brake sensor fault immediately. To double check I unplugged the new unit and re plugged the old unit in. Sorry to be the bearer of bad news but the old ECU was working perfectly, it brought up the two faults that I had on the new unit, no power to the ABS motor and the short circuit on the rear sensor PLUS the fault code 63 front brake pressure sensor. Reverting to the new unit the fault code 63 cleared the first it was reset. When I first inquired there was zero stock of the ABS unit in the USA. There were only five in existence in Japan. Mine was special ordered in from Yamaha Sports Plaza. The cost from the dealer where I have a home in Florida was somewhere in the region of $1,300 I paid $900. I have been riding my bike without ABS for sometime. It was bugging the hell out of me so when it came time to change the rubber It stripped it down and used the opportunity to do a bunch of jobs that I was going to get around to. I will let you know the outcome when the wheel sensor arrives.

I would be interested to know if anyone out there has a rear brake light flasher installed. I have one on mine but I am wondering if the pulsing current could affect the ECU as I believe the brake light wiring feeds to the ABS ECU. Just a thought....

Thank you bringer of the bad news.

As for your flasher question: Last week I talked about the code 63 with a Yamaha Tech and he advised me to first check the brake light wiring and the brake switches before thinking about replacing the ABS unit.
He told me that the ABS unit also generates a code 63 when it detects that the brake light is activated without pressure being built in the brakeline. The truth? I don't know, but in my case the wiring and the switches do what they are supposed to do....
I was hoping that you found yet another (far) more affordable fix, but based on your write-up I now see a new ABS unit in my near future. :'(

What version did you buy, the original one or the latest, upgraded, version (23P-85930-19-00) ?

 

[scopeusa]

Finally after being delayed by a visit to the Yukon I arrived home to the Caribbean and my rear wheel sensor and starter relay had arrived. After installing both I took the bike off the table and rode it around the yard where upon the speedometer immediately came back and the check engine light went out without needing to go into the main ecu diagnostic reset. Back to the shop and connect the test lead, ignition on and kill switch off. A dozen or so jabs at the starter button and the abs light went into .5 second flash mode. Disconnect the test lead fire it up and ABS light and Traction Control cleared. I have ridden a couple of hundred miles and everything appears fine. On the bleed question, I had no problem with any air from just the first bleed. Yamaha do not have any specific procedures for purging the system and a second bleed after checking the ABS (initiating the pump test sequence) made no difference whatsoever and evidenced no change in the lever/pedal positions or pressure.