K Line 1 Status: Stuck Low

[mferguson]

Trying to connect to 2004 1150GS for first time.
Old yellow 911 - used on other bike but not this bike)
911 indicated was not able to connect to controller
A scan results in an indication that K line 1 is stuck low.
I assume this is one of the communication lines on the bike and it may be grounded.
Does anyone know what this means?
(Bike runs fine - but am having ABS problems - hence the use of the GS911)

[WayneC]

The yellow GS911 diagnostics to the bike is via K-Line protocol, the R1150 has separate pins for Engine ECU & ABS & so one pin is stuck low (earth), since you have ABS issues it would suggest that is the ABS pin

I assume since you can do a scan that you see the Engine ECU details in the scan ?

What is odd though is K-Line 1 is Engine ECU & K-Line 2 ABS

10 pin Diagnostics Socket Pins
1   BMS K-Line1 Br/Sw
2   ABS K-Line2 Br/Bl
3
4   Earth Br
5
6   Bat+ Rt/Ge
7
8
9   Rect Bl
10   Ignition On Ge/Gr

[mferguson]

Thanks Wayne - I can’t see the engine ECU either.
The scan I did was under the setup menu.
The 911 was able to read the battery voltage (12.2V).
The ignition voltage reads as 0 and the 911 gives error that ignition is off (it is ON and the run switch is in run position.
I might have a clue - I read elsewhere in this forum that the sidestand being down could affect this.
I know that if in gear this would prevent engine from starting and might account for the 0 ign. voltage. The bike was on center stand but there is a good chance side stand was down during test - I plan to check this tomorrow.

[WayneC]

OK understood re your scan & lack of any ECU's

Not certain re side stand on the R115OGS, would have to look at a wiring diagram but on the 650GS single the side stand removes power from Engine ECU when it is down so perhaps it is the same on the R1150GS

[mferguson]

Thanks - I’ll test the side stand tomorrow and also unplug the ABS module to see what effect that has and report back.

[mferguson]

Reporting back on today’s experiment:
- side stand was not the comm issue (although did not test if it could cause comm issues)
- ignition voltage only shows up when bike is running - so that was nothing to be concerned about
- Unplugging the ABS unit solved the “K1 stuck low” condition - so clearly internal issue in ABS unit.
- can now communicate with engine ECU
- notes of interest:
     - ABS failed completely and suddenly mid ride - illuminating the “brake failure” light (solid on)        but no “!” Light. Was restricted to residual braking (this is the servo system)
     - regarding diagnostic lines - this bike does not appear to have a k2 line present - only k1 which further supports internal ABS failure
     - Pin-outs on this bike 04 dual plug, servo 1150gs:
           1: brown+black (k1?)
           2: none
           3: none
           4: brown (gnd?)
           5: none
           6: red+yellow (bat?)
           7: none
           8: none
           9: blue
           10: yellow+grey
Conclusion: looks like I need a new/used/rebuilt abs module. I like the servo brakes, so I will likely repair in one way or the other - I have a spare supposedly good used unit - will plug that into bike next and see what I have.

[WayneC]

Good to hear you worked out the cause of the K LIne held low, it seems like there is an error in my spreadsheet of diags pins on bike models or there was a change during production of the R1150GS of putting ABS onto K-Line1

There is information in threads on the forum by JugHead re rebuilding ABS units, may be worth reading

[mferguson]

Thanks Wayne. Studying wire diagrams and parts fiche it appears that the elimination of K2 on the 1150GS may correspond with the change to IABS and/or dual plug at the end of 2002. There was a new engine ECU that came with the dual spark in 12/02 per parts fiche. The IABS came in 9/02. Dual Plug wiring diagrams show a single K1 line used by both ECU and ABS. Single plug diagram shows K1 (ECU) and K2 (ABS).

I appreciate the help and will check out Jughead’s thread