VSS Sensor Spikes on Honda Civic

I’m currently troubleshooting an issue with my Honda Civic with a D16A6 engine and an ECUMASTER setup. Despite successfully obtaining speed readings from the Vehicle Speed Sensor (VSS), I’ve encountered persistent spikes in the value when the speed exceeds 50 km/h. Despite numerous attempts to adjust settings, the issue persists.
The VSS sensor, a Hall-type sensor, is powered by a 12V supply and features three wires.
I was wondering if you could provide guidance or perhaps share a template for Honda D or B series engines that could assist me in resolving this issue.

What kind of spikes are you having?
I`m also having a spikes problem just from when i have installed EMU Black (more than 2 years).
Same as you i have factory 3 wire VSS sensor.
In my case spikes are not related to speed, they can occur are low and high speeds and the spike can be negative and positive (it sometimes happens that when i just start rolling the speedometer goes to max for split second…).
Changing input filter and pull-up values does not have any effect on this issue.
Log attached.

11194836.zip (2.6 MB)

Yes, I had a spike like yours, but mine was even worse.
But yesterday I set the divider to 2 and the spike are nearly totally gone. I tried the car on a jack, and now I need to test it on the road.

this is my setup

i am useing EMU black on an Audi TT with 1.8T engine for 3 years now and have the same problem.
In my case the sensor is connected to the instrument cluster and the IC is generating the frequency signal for the other ECUs.
I use following settings:

Till now i thought i have a bad wiring somewhere or IC is faulty, but it seems to be a general or setting problem.
If someone finds the holy grail for this plz post it here. I will also start to go on playing with the settings.

is strange that you are using pull down normally most signals generated are to ground and pull up would be required

To this line several ECUs are connected and i think it is enough if just one is doing the pullup…and it seems an other ECU is doing the pullup here.
I think for a simple reading here the setting doesn’t matter, but u are right…probably it is better to set it to none or pullup.
Will try this.

I played a bit with my settings:

  • pullup, pulldown, none: doenst make any difference; identical signal+quality; issue still present
  • increased the freq devider to 8: issue still present
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I have swapped the vss signal wire to the FlexFuel input and selected “Sensor at FlexFuel input” in the options, no other changes. That fully fixed the problem. Tested on ~ 100km distance and not a single spike.

I have also tested the pull up,down, none (using FlexFuel input) and it did not make any difference, which is strange. The VSS sensor should be open drain so any thing other that pull up should turn off the signal.
I will check this signal on oscilloscope to have a better picture what is going on.

OK i have checked few things and here are my findings:

  1. Changing the pull-up/down/none is not working on the FlexFuel input. It has 10k pull-up no mater what we choose in the settings.
    Is this intentional or my ecu is broken? If intentional then the pull-up options should be grayed out when FlexFuel input is choosen.

  2. Honda VSS sensor (from Accord VI gen, can`t say for others) have build in pull-up to 5V already integrated. There is not external pull-up needed.

  3. I have checked the signal from VSS sensor and it is very nice 0-5 V square wave. No anomalies detected. I have the signal in both inputs - they are the same. In that case why if the signal is connected to VSS input the spikes are occurring and on the FlexFuel input they are not… This is very strange issue.
    Maybe Ecumaster team can assist on that?

Do you know from which Honda engine series that VSS is, is it from the h series?

Its from F series F23Z5 to be specific. Accord 98-02 EU.