m800 cb500 sync error

[benjamindp]

hi,

While cranking the engine, the diagnostic errors says "error sync signal".
But sync/ref synchronisation is OK.

Also I don't have ignition while cranking. But everything is working fine in test outputs.
We use the bosch module 0 227 100 211.

this is the capture of the ref and sync signal.

capture

refsync.jpg (269.4 KiB) Viewed 12763 times

these are my setups for ignition and ref/sync

ignition

ignition.jpg (207 KiB) Viewed 12761 times

refsync

ref sync setup.jpg (231.85 KiB) Viewed 12761 times

don't know why we don't have ignition while cranking and why we've got the sync signal error.

[Stephen Dean]

Hi,

Do you know why the Ref signal has a +5V offset? it is not that common to see such and offset on a Magnetic sensor. Your missing teeth are also showing up in the trace, this can lead to the tooth count being wrong and the sync position not being correctly calculated.

[benjamindp]

The offset is gone now. But we still got the sync signal error.

The weird thing is that it isn't always, last week we started the engine. But now it appears continuely so we can't start the engine. Nothing is wrong with the wiring and the setup is still the same.

also when we take a capture, both signals ( ref and sync ) are good.
But when we add an chart recorder in motec for the sync voltage, the peaks aren't comming at the same time.
Sometimes we can crank it 2mins without a peak and then we got 3-4 peaks in some seconds.

[AdamW]

I don't think 15 teeth is enough to use ref/sync mode 7. The help file for mode 7 says that the number of teeth will effect the minimum cranking RPM that is required to allow the engine to sync so I suspect you are below that threshold. The suggested minimum is 60 teeth for 100RPM so knowing a bike engine probably cranks at about 2 or 3 times that I would think want more like 24 or 36 teeth.