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VR sensor noise

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I have a VR sensor in a transmission that I monitor vehicle speed. It is a Tremec that uses a Ford-style VR sensor. It has performed without issue for 5,000 miles.

I recently needed to clean up the wiring on the vehicle and now I am seeing noise on the same circuit. The unit will spike from 30mph to 714mph and back in less than a second. (My car performs well, but it doesn't have this type acceleration ;-) )

Tried shielding the wire, checking all connections but can't find the noise source. Some Google searches suggest a 10k resistor across the poles of the sensor. Others suggest a .56mf capacitor across the poles. Understand the concepts but resistors and capacitors are two different things.

I can't easily change the sensor, requires the drivetrain be dropped to get to it. It could be the sensor but I suspect the noise is getting into the line. I've attached a file showing RPM and speed signal. I've determined it ONLY happens with the vehicle moving which might indicate the sensor but still looking at the signal, it looks like noise. The flat lines on the upper graph indicate the vehicle is sitting still. Notice no spikes in these areas. I see this same thing on all log files.

All of this is above my paygrade. Any ideas on how to minimize the noise, if that is what it is.

Hoping for any guidance from this brain trust

Paul

Just a shot in the dark:

Connect a 1kOhm resistor instead of the VR Sensor and log data during a test drive. Are there spikes or not?

Does your ECU have the ability to log the raw signal of the sensor, like its frequency? Or do you have access to an oscilloscope (like a picoscope) connected to the wiring at the ECU during a drive?

You could also connect the sensor via temporary wiring that would be isolated from the other wires and go for a test drive.

Finally, is there a setting for a voltage threshold / filter to adjust for the VSS for noise rejection?

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