Here's an update following another test run.
In the first test, I used the fast idle to get the engine up to temperature quickly but the graph showed the ‘Idle switch’ turning on and not turning off again.
I ran this test specifically to test whether the ‘Idle switch’ was working correctly and got a completely different graph!
https://drive.google.com/file/d/187Un1_JSCnUjVkPXQtLOAh4izD9A_d8d/viewFrom the very start, the GS-911 recorded the fast idle being turned on and off. I’d noticed this at the very start of my first test but when the engine was up to temperature in that test the ‘Idle switch’ remained on.
In the second test the ‘Lambda closed loop control’ remained off until the engine temperature reached about 58 C, when it flickered briefly. When the engine temperature reached about 64 C it remained mostly on, which means, if I’ve understood things correctly, that the ECU is using the Lambda/O2 sensor in its calculations.
At about the same point, the ‘Lambda sensor voltage’ is seen to drop and then follow its expected pattern of jumping between high and low voltages. Whilst this is much, much closer to the expected pattern, I’m uncertain whether it’s actually responding quickly or slowly when compared to other published graphs out there.
Interestingly, as the engine temperature continues to rise, the ECU switches back to open-loop and the ‘Lambda sensor voltage’ goes back up to the 870mv range seen on the first run. I suspect that the ECU is running a rich mixture in an attempt to control the engine temperature.
It seems that my first test was invalidated by keeping the fast idle switched on for so long during warm-up, which may have caused the ECU to remain in open loop, especially as the engine temperature continued to rise. It’s all down to the programming, and since we don’t have access to the spec or the code, all we can do is monitor the behaviour and comment, possibly speculatively.
Given that I’ve been able to observe a more normal ‘Lambda sensor voltage’ graph I’m going to leave it at that for now.
For the benefit of others who may come across this post:
My bike is a European spec R1100S manufactured in December 1998. It does not have a Cat Code Plug (CCP) fitted. I checked this out with an independent BMW business here in the UK, motorworks.co.uk, who confirmed that EC models were not fitted with a CCP. The GS-911 ECU readout shows the ‘Motorcycle Variant’ as ‘R1100 S ECE-Kat’. That reads like ‘EC model with catalytic converter’ to me, and I believe that this also refers to the set of maps that the ECU is using (please refer to
http://forums.bmwmoa.org/showthread.php?58495-Coding-Plugs-R1100-R1150-Decoded&p=994823&viewfull=1#post994823 for R1100 & R1150 CCP variations).