Topic

Hi. I just did a live data log run with Pscan to gather EPAS info from my MGF.
Glancing at the laptop while driving, I could see the vehicle speed changing up to 100kmh but the log hasn't recorded any value above 0.6kmh.
Question 1: Does anyone know if the vehicle speed is calculated by Pscan from raw speed sensor outputs or has it been delivered directly to Pscan via the CAN bus?
Question 2: Might this indicate that my speed sensor is faulty?
Thanks in advance for any help.

if you are logged into the EPAS module then pscan is getting the data from the EPAS module.
My understanding is that the EPAS gets vehicle speed from the ABS, but pscan doesn't get involved in that.

I think you are saying that the speed from the EPAS live data is working when you display it on screen, but that when you use logging it doesn't.

Is that what you are saying?

That's what I'm saying thanks

Could you send me the log file, or attach it to a reply here please?

Hi. Please see attached file for details.

I know that this is off topic but there are currently two people (Notanumber and Me) who are currently or soon will be fitting MGF or TF EPAS into MGB's. I did quite a bit of research about this a couple of years ago and it seemed the EPAS got its speed signal from the speedo, the wiring diagram shows this. However I recently purchased a TF without ABS and it had one ABS sensor on the rear nearside driveshaft. After enquiring on the forum I was told that non ABS cars obtained a speed signal for the Engine ECU, if the EPAS gets the speed signal from that makes a huge difference to the number of pulses that we must give it.
According to this; https://www.the-t-bar.com/forum/9-mgf-tf-pitstop/96551-instruments-calibration-data the speedo receives 6600 pulses per minute at 100 mph, this calculates to 3996 pulses per mile however if it is derived from the ABS ring with maybe 45 teeth (I haven't counted them) and 880 tyre revolutions per mile would give 39600 pulses per mile almost exactly ten times what we are led to believe. If we go with the 3996 signal and the requirement is tenfold then the variable assistance will not exist until after 150 mph on the other hand vice versa the variable assistance would be non existent after 2 mph leading us (and many others who have tried this in other makes of car) thinking it doesn't work. Any help in this matter would be much appreciated

That is a very interesting observation & analysis, is it a coincidence that one figure is pretty well ten times the other?
The application of our EPAS system to other vehicles & the apparent failure could easily be associated with this disparity.
Thank you, that provides food for thought, not that I’m short of things to ponder & nor do I have anything in mind on which to apply that information.
M

kiwikk wrote:

File Attachment:

File Name: 5.xlsx
File Size:106 KB

Hi. Please see attached file for details.

I don't quite understand why it would show a road speed on screen but then not log them. I am going to need access to a running and driving MGF to get to the bottom of this one.

It would be great to understand. It seems unlikely they fitted different configuration EPAS ECUs for ABS and non ABS cars.