EPC - some do, some don't, what are the facts?

[neckarsulm]

I was reading the advert on ebay for the chap that fits OEM cruise kits to the S4 and how he states it can only be done on cars with EPC (electronic pedal control aka drive by wire) (turn ignition and if EPC light comes on you have it). I assumed all S4's had this and that he was just mentioning that because he does other models too but then I was reading the road test of an S reg S4 Avant in a 1999 Audi Driver magazine and there is a picture of the clocks with ignition on/engine off but no EPC light! But my 4/99 car does have an ECP warning lamp.

So am I right in thinking some S4s have a throttle cable or do all have EPC/drive by wire but the very early ones don't have a warning light? Having said that why would having no light mean you can't have cruise..hmm

Thanks.

[lemond]

Hmmm that Audi Technical Bulletin on 01/98 is all about the new 2.7 Biturbo and it reads as though it is a key feature on this motor...I asume they all have this EPC .... they call it Electronic Power Control...an interesting read

Or am I just a bit of a nerd.

I'm sure one of the specialists will know

Paul

[shineydave]

must admit, i thought it was power control too

[MCB]

I thought for cruise control to be fitted to your car it has to have the electronically operated throttle valve and I may be wrong (probably) but I thought not all S4B5’s had this???

[nickb834]

All S4's (B5's) have fly by wire throttle's, as in stepper motor driven throttle butterfly.

EPC means "Electronic Powertrain Control" It's got nothing to do with Pedal Control (thats YOU the drivers responsibilty

I'm sure of this but do correct me if I'm wrong.

You can do the cruise retrofit on all the B5 S4's AFAIK

Some cars don't have ESP, which is "Electronic Stability Programme" I beleive, my two prefacelifts don't / didn't have it for example.

[lemond]

According to Audi document EPC = Electronic Power Control.... that Tech Bulletin no. 198 is OK....

[S4TAN]

"Electronic Powertrain Control"

Bang on the money ...

( it's in the manual ... )

[lemond]

http://www.s4-mtm.com/images/Audi_S4_engine_english.pdf

Ah well it dunt really matter, but in this excellent tech guide, which I guess you have all seen already, written by Audi (hopefully) it says Electronic Power Control...

It is probably a translation and means 'Englischer Pilloken Checker' or 'Extreme Pedant Check'

There is a room full of Audi boffs monitoring the net and laughing (maybe) at the Audi fetishists tying themselves up (steady on) with their deliberately vague or changing terms.

Manual... bugger!... my car came with all little books (service etc.) apart from the handbook which the owner had lost! Ordered one and they got the Avant version.... so never unbagged it... I'm awaiting the saloon one now!

[lemond]

Any road up!

Do they all have EPC?

I just assume this tech doc is related to the engine and it was 'launched' with such features (que the Audi boffs laughing)

[SimonS4MTM]

All S4's have drive by wire.

[MCB]

So are we saying that all S4B5's can be retrofitted with cruise control?

[neckarsulm]

Not according to this (the chap that fits them for a living);

http://cgi.ebay.co.uk/AUDI-A4-CRUISE-CO ... dZViewItem

"AUDI S4 (1998-2000) ( NOT FOR NEW SHAPE) ONLY MODELS WITH EPC LIGHT "

[neckarsulm]

Nickb, have you read http://www.s4-mtm.com/images/Audi_S4_engine_english.pdf as on page 44 it draws clear links between EPC and the electronic throttle pedal, I agree it doesn't mean electronic pedal control but it still relates to the drive-by-wire feature which means the car doesn't have a throttle cable (I should have said I work in the motor trade and have diagnosed many EPC light issues using VAG COM and they all relate to the device which converts throttle pedal position into an electric signal used by the ECU to control enrichment).
If you think about the potential effects of a drive by wire problem, you can see why there is a need for a warning light!
The reason this relates to cruise control is that cruise control can be used to adjust the cars speed and this is much easier when there is no throttle cable, just an electronic signal.
That self-study guide (what a bloody useful document!) is dated 1/98 so it seems safe to assume all B5s have this but our Ebay cruise installer hints otherwise and that pic I have suggests this too.
Can anyone have their ignition on, engine off and not the EPC warning light showing?
When I can I'll photograph the Audi Driver pic and post it.

[neckarsulm]

I noticed today that my ECP light goes out after a bit with ignition on/engine off so the VW Driver mag car probably is the same as mine with an EPC light, so ignore that then.
That just leaves us with the Ebay cruise installer's comment - would you trust something said in an Ebay ad or something said in a document drawn up by the Ingolstadt boffins behind the S4..?

[GTMSpyder]

Slightly off-topic but has anyone replaced one of the earlier cylindrical EPC throttle sensors with a later type (black plastic mounted directly to the throttle pedal)?
,
If so is there a converter lead to change from the flat socket on the EPC box to the D shaped one on the loom?