MoTeC Global Forum

Hi,

Currently, I am working on diesel engine tuning with an MoTeC diesel M142 ECU. I completed wiring and installation part. But ECU is unable to cycle lock. It requires so many cranking for hitting the cycle lock. Because of, some problems like: ECU is indicating “noise” and "missed tooth" in the engine speed reference diagnostic. I changed the narrow pitch threshold to the minimum (40%), less than 40%, its indicting "invalid narrow pitch threshold".

After so many crank, some time hit the cycle lock. But in running condition, ECU is continuously showing "rejected pulse" in engine speed pin diagnostics. I tried my best, but problem is not resolved yet.

Please find related files in the link below.

https://drive.google.com/open?id=1GIU9T ... f6oyb-R0Pp

I request you to help me in sorting out this critical problem.

Thanks in advance.

To debug this you should be using an oscilloscope (Digital Storage Scope is best) on the input signals. If you don't have that, then the next best is to use the Input Capture feature to see what the signals are looking like. Your problem may be configuration, but it's likely to be a wiring and/or sensor/trigger issue (ie, gap incorrect, runnout in the trigger wheel, sensor not mounted perpendicular to the trigger teeth).

Hi David,

Thanks for your quick response. I am attaching ref/sync capture and parameter snap. Please suggest what is the main cause.

Thanks.

You have a Mag sensor for the Engine Speed Pin, so the Engine Speed Pin Pullup Control should be set to Off. Reduce your Wide Pitch Threshold to 150%.

You also have a voltage offset on the Engine Speed pin of around +1.1V, this needs to be compensated for with the Engine Speed Pin Threshold if you can't get the signal to cross at 0.0V.

I replied to your similar post on the HP Academy forum, but just for completeness sake I will add to Stephens reply here too, your input capture is also showing a Rising edge signal on the crank so you need to change your engine speed pin active edge to rising.

SDean wrote:You also have a voltage offset on the Engine Speed pin of around +1.1V, this needs to be compensated for with the Engine Speed Pin Threshold if you can't get the signal to cross at 0.0V.

I reckon that will just be due to the pull-up being on, with a bit of luck that will come right on its own once he turns it off.