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Digital hall effect crank sensor reads position changed

MoTeC M1 Software Tutorial

Discussion and questions related to the course MoTeC M1 Software Tutorial

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Hi guys,

Just started to tune my car the other day and the motec m1 software has a large learning curve. None the less I ran into an issue regarding my crank sensor channel changing from OK to position changed around 3000-4000 rpm and the engine sputters which makes sense, but if I let off the throttle and get back on the throttle it seems to be OK. So the first thing I checked was my crank gear trigger wheel. It appears to be fine. What is the correct way to set up your hysteresis and denounce for digital hall effect crank ref and cam sync sensors. My threshold is set to 2v and set to falling edge. Hysteresis it's set to .8 all the way across. Thank you

Hi Luke,

What Reference Mode are you using? Do you have a input capture of the signals?

Normally what is happening is that the sync signal is moving around and the edge position is changing in relation to the sync point of the crank.

Hi Black Rex,

What do you mean what reference mode? Thank you.

Hi Luke,

The Engine Speed Reference Mode that is set in 2: Initial Setup | 3, Ref Sync that informs the M1 of the Ref and sync patterns to be used to obtain cycle lock.

Hi Blackrex,

I'm using multi tooth four stroke. 12 tooth trigger wheel. Offset is 430. Blank ratio is 10% wide pitch is 150% narrow pitch is 50%. I forgot to mention my denounce for cam and crank is 0 = 100 500=80 1000=80 2000=80 10000= 80.thank you



How close to the active Ref edge is the Sync edge? the reason that I ask is that with a multi tooth setup like that, as the Ref has not way for the M1 to recognise whereabouts in the cycle the crank is (due to no missed/additional teeth), that if the sync edge moves then the M1 can't recognise this occurring and it just re syncs on the next tooth after the sync position, so I would check using the input capture function that the Sync is not moving.

Also, with the Debounce, the higher the engine speed, the lower the Debounce values, I would start at 60 and then go down from there, try;

0 = 60

500 = 60

1000 = 40

2000 = 20

10000 = 10

If you are still getting errors try either halving or doubling the numbers in the region that you have the issue.


Thank you for your help. I'll let you know how it goes. I'm also going to post a ref sync capture. Soon.

What engine are you using LukeW?