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As some of you will know, I have an intermittent starting problem, the crank shaft sensor thing has now been changed and its not that. The garage seem to think its one of the relays underneath the ecu or ecm what ever its called.

Now on the RS4 it has 3 relays and some fuses, when the garage looked it up on there scanner / web site thing it showed a different layout and an extra relay and fuses in a different place so this has not really helped.

My question is out of the 3 relays, does anyone know which one is the ecu / ecm power relay ? its at least a start at solving the issue as the car wouldn't start again today when I collected the car on a different unrelated job (new clutch) the garage removed the ecu and there was 3 relays, I pushed them in and the car started up? BUT remember the car does start and not start so it doesn't mean this was the issue but as I say the garage has said why not at least replace it as it was showing up on his snap on fault machine.

For the effort to get at them, just replace them all.

Some good info here, the last time it was discussed. There are also some others under the dash as well, if the problem persists.

viewtopic.php?f=35&t=118912

yes I guess that makes sense to replace them all, wasn't sure if they cost a lot of money though hence thought id replace the one only. Where can I buy these or are they audi stealer only ?

TPS sells them, about £17 off the top my head.

cant see them on there, and have no idea what im buying either other than I think the ECM engine control relay, but don't know which of the 3 it is, cant find anything online to help either or on you tube lol, trust us all to have a car with lack of online help

I had same problem with mine started 9 times out of 10 but that one time would be at a busy filling station
Annoying

I changed all my relays £15 each
Clutch switch
Start button
Only item cured it was the starter motor it’s self
Around £350 - £400 fitted can’t exactly remember




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Edit

WRS4 wrote: ↑

Mon Jan 07, 2019 6:39 pm

cant see them on there, and have no idea what im buying either other than I think the ECM engine control relay, but don't know which of the 3 it is, cant find anything online to help either or on you tube lol, trust us all to have a car with lack of online help

Part numbers are in the thread I linked earlier, read it


Good point Andy, I always forget the starter motor can cause the same issue.

Surrey Sam wrote: ↑

Mon Jan 07, 2019 7:12 pm

WRS4 wrote: ↑

Mon Jan 07, 2019 6:39 pm

cant see them on there, and have no idea what im buying either other than I think the ECM engine control relay, but don't know which of the 3 it is, cant find anything online to help either or on you tube lol, trust us all to have a car with lack of online help

Part numbers are in the thread I linked earlier, read it


Good point Andy, I always forget the starter motor can cause the same issue.

I did read it but its not pinpointing the correct relay, plus the numbers given are not the numbers showing on the top of my relays for some reason, as for starter surely the car wouldn't turn over at all ? mine turns over very strongly just doesn't fire up on the odd occasion which as Andy said, it does it at an annoying time such as a petrol station

just going to see if I can get a picture, may help

If the problem is the fact that it’s turning over and just not starting that will be something un related to the starter then .

No EML showing ?


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so I am assuming these are the ones that need replacing, and the man at the garage thinks the same too as they are directly underneath the ecu/ecm under the scuttle panel drivers side. two of them show 614 and the other 373, anyone know which is the actual engine power relay / module ?

To an extent, they both are.

The tallest 614 relay (J271 - location 2) is known as the Motronic current supply relay.
The lower 641 relay (J757 - location 3) is known as the Engine component current supply relay

The part number was 8E0 951 253, but the relay has been superceeded by relay 644 4H0 951 253, it may have been superceeded again but I don't have any more upto date catalogues. I can't be clearer than that, as I said earlier just replace both.

Surrey Sam wrote: ↑

Mon Jan 07, 2019 8:33 pm

To an extent, they both are.

The tallest 614 relay (J271 - location 2) is known as the Motronic current supply relay.
The lower 641 relay (J757 - location 3) is known as the Engine component current supply relay

The part number was 8E0 951 253, but the relay has been superceeded by relay 644 4H0 951 253, it may have been superceeded again but I don't have any more upto date catalogues. I can't be clearer than that, as I said earlier just replace both.

Your a star thanks fella, much appreciated

This is getting beyond a joke now, so according to Audi, non of these relays are actually the one I need ??? here is the email I got.

The Relays are as follows :

Marked 614 is a Fuel Pump Relay £20.68
“ 373 is a Heater Relay £20.6

There are few more Relays in the same location they will all have a Audi Number stamped on them..

Starter Relay is £41.28
Servotronic Relay is £151.55

Unfortunately there do not list an Engine Power Relay, but there is on On-Board Control unit underneath which the relays sit on that is £356.28.

Kind Regards

So the garage is telling me one thing, Audi another, and I have no idea who is saying what and which advice to take. Surely someone knows ? all I need to know is exactly what relay to buy and which from the picture I have supplied should I change, yes I get I could replace all 3 but from what Audi say non of these are actually the one I need to change anyway or they don't have anything listed regards the one I need to change so WTF