R1100S ABS Supply Voltage?

[Roddos]

Hi

I’ve been looking at a friend’s R1100S ABS system after he has been experiencing the ABS Warning light coming on and servo failure at low speed,
The fault codes showed several “Internal control unit error” these cleared and so far not returned however looking at the ABS Status its showing Supply Voltage approx. 2v below normal battery voltage in all conditions ie engine running , ignition on system operated etc, the charge rate at the battery is good approx. 14v and a carrying out a volt drop across the supplies  & earths shows less than 150mv under load,
Has anyone else noticed supply voltage low or come across this?
I’ve attached a PDF of the scan

Regards
Rod

[kobus]

Not sure about the supply voltage, but the warning light will come on because of the defective rear light error.

AFAIK on the R1100S the rear light bulb has 2 filaments, both should be working properly.
Fix the bulb first before looking for something else.

[Roddos]

Hi

Many thanks for your reply

The bulb was a separate issue and came on while testing, as you say it uses both filaments and 1 had a slightly high resistance, a new bulb cured that problem however the ECU voltage still shows below the normal battery voltage (although the measured supply and earths are normal)and still getting the Internal error faults, looks like it going to be a new ECU 

[Alexm1]

Hello, I have a situation that sounds exactly the same as what you describe except I have no error. I discovered a battery voltage problem when I took delivery of a new GS 911 and was scrolling through the various screens. See my post under general.
Alex.

[Alexm1]

Roddos, not sure if this is still an issue for you. Jughead took some readings on his unit and there was no voltage drop which suggests there is an issue. I have not followed it up yet as I am not getting any errors, just the low voltage; ABS and brakes work fine. You can see jughead s readings on my thread under general.