EPAS and PSCAN

Hi all, my name is Nigel and am new to this forum.
I don't own a MGF but I do have the EPAS from one and it's fitted to my classic car which works very well most of the time but does glitches now and then.
Could anybody tell me if error codes could be read from the stand alone EPAS box with PSCAN.
I have wired in a diagnostic socket, type j1962 with the pink wire (No16) from the EPAS unit to Pin7 on the J1962 plug, 12v to Pin 16 and ground to Pin 4 & 5 as per circuit diagrams but none of the readers I've tried have worked.
Would appreciate any thoughts.

Well I can’t answer your question, but I’d like to ask you one if I may, what are are you running it in?
Apart from my MGF I also have a Triumph TR-7 which I intend to fit a V8, I happen to have a spare Epas from a MGF, and I plan to fit it to the TR.

Hi Cobber

its fitted to a 1951 Citroen Light 15 which is tied in between original steering wheel and rack.

I can't answer your specific question, but I do know the EPAS pulls a lot of power and presume you have upgraded to an alternator and bigger battery to handle it?

Yes I agree they do pull a lot of current, mine is almost 30A if held on full lock, I've upgraded to a 70A alternator and using biggest battery I can get in space and the new wiring harness I made is well over engineered to carry rated requirements. I think the only realistic way I'm going to find the answer/error codes to my post is find a PSCAN module and try it

just did a quick google on battery capacity for F/TF couldn't find a definitive answer seems to be 45-60 AH with the EPAS cars needing the most, what size is yours (stop sniggering out there). I'm also pretty certain that on F/TF's the ECU needs a signal from a speed sensor to enable the EPAS this is (I think) to avoid battery drain when the car is stationary. If you have not replicated something similar in your installation perhaps it's draining the battery when on tick over/stationary leading to a lack of available power when needed. Your electrical knowledge seems much better than mine as I wouldn't have attempted what you have done so can you rig an ammeter into the circuit to see what it's pulling and when to discount my theory.
I know very little about pscan (got one but newbie) I wonder if it will wake up? without detecting an ECU etc. there is a dedicated pscan section on here you could try posting in there: Toolbar - Forums - Index - pscan diagnostics.

Hi and welcome to the forum Lexus

I can confirm that the pscan does connect to the EPAS ECU but I can't remember exactly what information it gives.
A regular OBD reader doesn't connect to the EPAS ECU because that isn't a requirement of the OBD2 regulations.

James

I've just looked at battery and it's a 70A battery so should be ok there, but perhaps as per you suggestion to putting an amp meter inline and monitoring the steering whilst driving rather than static may show something, if it is an overload issue the draw is either of short duration or lowish as the 40A fuse has not popped yet, I have a pico setup so can log the draw that.
As for speed signal, I have a module attached which produces two square waves, one at 82Hz, this feeds into the EPAS on Pin 15 and represents the engine running, the second signal is variable via a pot and is between 19Hz and 295Hz and feeds into Pin 7 of the EPAS and represents MPH, this pot allows for adjustment of assistance to the steering. I have also wired in a warning lamp as would be in the dash of the donor car but as yet have not seen this lit when fault occurs. Perhaps someone can confirm that the warning light is lit at ignition on position and goes out once started, I believe as the pulse generator I have attached to my EPAS start's as soon as ignition is on it doesn't have a reason to light my warning lamp.
Thank you for the feed back you guys are giving me.

I have to admit that I know very little about the EPAS on my 2004 MG TF other than the fact that it seems to work correctly.

I have just checked. The steering assist warning light on the dashboard illuminates when the ignition is switched on. It goes out once the engine is started.

I hope this helps.

Lexus - what do you use for pulse generator, I have wondering this for 15 years for when I put EPAS into my T16 Maestro.

For quickness at the time I purchased a unit off fleabay about 12 years ago for about £30 but unfortunately it didn't work as they'd wired it wrong but once we'd sorted that it worked OK and still does, it produces two square wave output frequencies, one to represent engine RPM and the other to represent MPH.
These frequencies can be generated using ready made 555 timer boards and adjusted to suit or purchase the few components needed and assemble yourself, I've not seen a ready made unit for quite some time but would assume they can still be found as I think it's a popular conversion to fit to kit cars etc so would need these inputs to the EPAS.

Here in Oz a mob called Jaycar sell them in kit form and also sell another kit for a controller which can be used to plug in and adjust the speed set points so as you can adjust when the assistance is applied and when it fades away