EPAS speed signal

Is there a way of over riding the speed signal requirement of the EPAS ECU.

Why you may ask? Simple, I have an EPAS column and ECU to fit in to my maestro which has a manual rack which can get quite heavy at low speeds.

Its possible to wire it so that its on or off..

But to make it speed sensitive? Now that sounds tricky..

I think you would have to find out what signal the ecu receives from the speed sensor and somehow simulate it. Haven't a scooby how though. :nonod: You would need an elektrikiry ekspurt. :dry:

I've got an electronic box of tricks especially for this very purpose, as I'm looking a fitting a spare MGF set up into my TR-7.
I'll need to have a dig in the shed to unearth it and then I can give you the part # and give you an idea where to get one.

Should be possible.

The 2 signals which are critical to stop the unit going into error mode (switching off the EPAS motor and disengaging the EPAS clutch) is the engine speed info from the engine ECU at plug C0159 wire 55 (this info also drives the tachometer in the display) and obviously the speed signal from the speed sensor at the gearbox.

The engine RPM has no effect on the steering but if the EPAS ECU receives an engine speed signal of over 2500 rpm for 30 seconds without any signal from the gearbox speed sensor the EPAS will go into error and disengage as it thinks there is a fault with either the engine speed sensor or gearbox speed sensor or related wiring.

Hopefully your Maestro should already have a digital tacho? So see if the signals are similar at the instrument cluster as the F/TF, the values don't have to be exact but just enough within a range to satisfy the EPAS ECU.

Regarding the speedo drive; I would imagine on your Maestro it's a cable drive? You could look to see the possibilities of fitting the speed sensor from an early MGF with EPAS that uses a cable drive for the speedo and see if you can adapt the sensor to fit your speedo cable.

The power feed cable to the EPAS also has to be large enough (3mm sq dia) as it draws quite a lot of current, if the cable area is too small the you will get a voltage drop at the unit and this will put the EPAS into error.

It’s a nice project, I am sure if you can get it to fit mechanical then the electrical issues above are all solvable, but I would be interested to see what Cobber has in his shed with his electronic box of tricks as there may be a simpler solution.

Brian.

Thanks Guys, especially Brian.

At the moment the speedo is cable driven but I suspect it will be going electric at some point.

I'll have to double check the column and ECU to see if they are mk1 or later.

James

Had a dig and found the digital pulse adjuster and the LCD hand controller
Although on the web page it doesn't mention that you can use it for power steering, it does say so on the packaging.
Now there is some assembly required as they are in kit form, so you do need to be handy with a soldering iron. I know a bloke that used the same kits to convert his Triumph TR-7 to EPAS, though he used an EPAS from something else (I can't remember which), I intend to use this on my TR-7 with MGF EPAS.
I might even get another for my MGF so as I can adjust the assistance more to my taste.

Here's a good omen......There's even a picture of an MGF on the packaging!

Jaycar ( the mob I got them from) will do international mail orders, but you may be able probably find the same stuff locally.

Thanks for posting that, it has given me some avenues to explore.

Soldering is no problem, I've built a ZX81!

Hi, I was just wondering if anyone has a part number and / or where I can buy it for the old type MGF speed sensor for EPAS. I mean the one with a speedo cable. I've been unable to source the part at all. Many thanks.

Google is your friend...

https://rimmerbros.com/Item--i-TXG100170