ABS ECU up in smoke.

[ferg]

I have a 2003 1150GS with the servo brakes. My dad took it over to his house to take it in for an mot the next day. He phoned saying how well it was running. The next day he went to head off, started it and only had residual braking with not even a peep from the servo. He deposited it back to me and upon taking out the servo block and opening up the ecu it was clear to see, and smell, that there had been some kind of catastrophic electrical failure.
I plugged it back in with the mildest hope that the brake light areas may be undamaged but alas no. It's all scrap. Or toast. Burnt toast.
What are the chances of finding a secondhand ecu at an affordable price? Or am I resigned to buying the new brake switches and modifying the wiring?

 

[boatman]

I think I read on here that those bikes can be “ de servoed”

 

[Santa-2512]

Send it to Mend it Mark

see what he can do

 

[Wrigsby1]

A bike that has been de-servoed may not then have ABS but will have far more effective and useable brakes...

 

[DrFarkoff]

@ferg No Need to Buy switches

Follow the instructions as per THIS POST

If you cannot see it ??
The brake failure I had on holiday was terminal as I expected - fried circuit board in the ABS ECU.

Yesterday I performed a 'servoectomy' and have decided to post the procedures in case it helps anyone else in a similar situation.
The servo removal and reconnection of pipework and electrics was carried out using existing parts only - it has cost me absolutely nothing apart from time and a few consumables.

Start with removal of the servo system itself together with redundant metal pipework - been documented on here numerous times and is relatively straightforward.
Reconnect the rear brake hose directly to the top of the master cylinder using the domed hex head brake fitting

Remove both flexible hoses and both rigid metal pipes from the front distribution piece,
Remove distribution piece - you will notice a small 'tag' on the reverse which locates against the frame and effectively fixes the orientation of the bracket.
By grinding/filing off this tag it is possible to realign the distribution piece as per the attached photograph and connect the two flexible hoses together using the existing connectors in the top metal socket (the one with two holes the same size).

That's the brakes reconnected - now bleed and sort the electrics to give you a brake and tail light again.

This is a piece of proverbial despite what others may have written about it - you dont even need any extra parts !!

1) Remove the blue ABS relay from the fusebox. This will extinguish the 'Brake Failure' warning light on the dash and as a bonus can be used to operate the brake light !! (no need for new switches as in other methods )
2) Strip back the sheathing from the ABS multi pin connector - identify wires and connect as follows
a) Grey/White wire (tail light feed) Grey/Black wire (12v feed) cut both and join together - thats your tail light sorted.
b) White/Yellow wire (front brake switch) and Yellow/Green wire (rear brake switch). Cut these two wires and join them to link brake switches
Now the wiring to the redundant 4 pin ABS relay
c) Pin 1 - Connect white/blue wire
d) Pin 2 - connect the THIN solid brown wire in the loom to provide a ground ( careful here - there are several brown wires c/w coloured traces and a Thick brown wire)
e) Pin 3 - Find the Yellow/Black wire and the solid green wire. Cut and connect these together and then to pin 3 of the relay
f) Pin 4 - Connect grey/yellow (tail light feed) to this pin

That all there is to it - you now have working brakes and lights.

I tidied things up by cutting and isolating all remaing wires on the ABS plug.

I have located the relay on the back of the battery under the seat so it can easily be changed if needed,

May consider fitteng some braided steel lines in due course, but for now, the bike is up and running, without any cost or waiting for parts - this may just help someone 'in the field' in the future

Dave H





I already did this with a few bikes that had that catastrophic Internal BBQ

Be aware roxters and R1150R series Plus K 1200 and Hexhead onwards need the electronics box to supply speed data to the instruments

Many Thanks to DAve H whoever they may have been as I think they have moved on from BMs now

 

[DrFarkoff]

I think I read on here that those bikes can be “ de servoed”

Yes they can even better there is a second method when theres a fried board like that !

 

[ferg]

@DrFarkoff that's ace thank you. So the speedo isn't linked into the abs ecu on the GS? I'd read that it was elsewhere but that may not have been GS specific.
My dad didn't notice that the speedo wasn't working when he rode it back, we're running on the assumption that he would of... the brake lights definitely don't work

 

[JohnnyBoxer]

@DrFarkoff that's ace thank you. So the speedo isn't linked into the abs ecu on the GS? I'd read that it was elsewhere but that may not have been GS specific.
My dad didn't notice that the speedo wasn't working when he rode it back, we're running on the assumption that he would of... the brake lights definitely don't work

Speedo on 1100/1150’s runs from a cable drive from front wheel

 

[DrFarkoff]

@DrFarkoff that's ace thank you. So the speedo isn't linked into the abs ecu on the GS? I'd read that it was elsewhere but that may not have been GS specific.
My dad didn't notice that the speedo wasn't working when he rode it back, we're running on the assumption that he would of... the brake lights definitely don't work

Only the Roxster used the ABS ECU for the speed as there is no speedo drive on them

1150GS and GSA are cable driven But I have seen the drives unscrew at the top and fall out or strip the plastic gears down at the wheel drive

All easily replaced

 

[Riceburner]

Only the Roxster used the ABS ECU for the speed as there is no speedo drive on them

1150GS and GSA are cable driven But I have seen the drives unscrew at the top and fall out or strip the plastic gears down at the wheel drive

All easily replaced

I'm just in the process of de-abs-ing my Ed80 Rockster: would you happen to know which wheel sensor feed the speedo needs? (Front or rear). Obviously I'd like to remove the one that's not in use.

 

[DrFarkoff]

I'm just in the process of de-abs-ing my Ed80 Rockster: would you happen to know which wheel sensor feed the speedo needs? (Front or rear). Obviously I'd like to remove the one that's not in use.

@Riceburner I have been told but have not tried to verify that the rear is primary of the two sensors But If it fails then the front supplies the signal

You could just disconnect the front one at the connector and test ride

Its usually Just by the frame number on the headstock if I recall although it may be tucked away a little further back

 

[Colt]

H Ferg
I have a unit from a twin spark bike had 30k miles on with working abs.

 

[Riceburner]

@Riceburner I have been told but have not tried to verify that the rear is primary of the two sensors But If it fails then the front supplies the signal

You could just disconnect the front one at the connector and test ride

Its usually Just by the frame number on the headstock if I recall although it may be tucked away a little further back

Cheers, I'll have a play when i get to that stage and report for posterity. (Given that there isn't a specific R1150R/Rockster forum anymore)

 

[ferg]

Speedo on 1100/1150’s runs from a cable drive from front wheel

Of course it does That's the drive I've refitted every time I've had the front wheel off Sometimes there's too much 'online diagnosing' and too little poking metal in the garage and thinking for myself.

 

[DrFarkoff]

Of course it does That's the drive I've refitted every time I've had the front wheel off Sometimes there's too much 'online diagnosing' and too little poking metal in the garage and thinking for myself.

The drive legs can get bent and the plastic drive "screw" can get stripped

Easily diagnosed by dropping off the cable and spinning the wheel and watching the spindle turn