daveo90s4

Hi all,

A problem with my S4 that I'm hoping for some advice.

Today while driving the engine cut out. The digital dash displayed 'differential control - off' briefly, then 'ABS Control Off'. Car would not restart. Earlier today the car had lost power very briefly and then too the 'diff control off' warning flashed up briefly before all returned to normal.

In April this year the car would not start one day - we diagnosed no spark and no power to fuel pump (was not a fuel pump relay problem) and so we thought probably the factory alarm system at fault. Happened to have brand new 928 637 160 00 relay on hand, put it in and car started straight up.


So today on side of road, removed that relay, put it back in and car started straight up. Got home, engine ran great, then idling car cut out again with same digital dash messages again. Un-clipped the LH and EZK brains, clipped them in, started engine, ran briefly, then stopped. Same digital dash messages.

Pushed it into the shed.

Now, car still won't start.

This is not thrust bearing failure. Engine winds over freely, just won't fire. Have checked with a spare plug on one lead - no spark. Coil wires all connected. Also, unlike normal, I do not hear the fuel pump momentarily energizing with ignition on before crank turning, so once again I believe I have no spark and also no power to fuel pump.

Suggests alarm system maybe??

I have a spare 928 637 104 03 alarm control relay, maybe the original has died?

Any help much appreciated.

Dave

ROG100

Crank Position sensor connection at harness - check.

uncre8tv

Cleaned all your grounds recently? And I do mean all...

https://rennlist.com/forums/928-foru...-geniuses.html

GregBBRD

Check the small red power wires that attach at the positive post of the battery. With all of those different things going wrong, they could be loose and you could be loosing power to the relay board.

Very common.

daveo90s4

Ta Roger, will check that.

Yes, earths are all good, did Wally's check about a year ago.

Dave

daveo90s4

Thanks Greg, will do that too. Hope it's that simple.

Dave

daveo90s4

Thanks Greg.

I did as you suggested.

First tried starting the car - still no start. (Good, problem mittent rather than intermittent)

Then pulled **** to open hatch but hatch motor would not cycle. Aha, gotta to a broad spread low voltage problem.

Get to battery. All the red wires a firmly attached to their little bar, but the bar itself is a bit loose.

Tighten that, and then turn ignition key.

The fuel pump does its momentary whir and then with the next click it fires up immediately.

Seems like you nailed it Greg, thank you very much indeed. We've got a club day out today, so looks like I'll be able to make it after all. (I hope it stays fixed all day!).

Once again thanks Greg and thanks to all with their suggestions.

Dave

James Bailey

Sometimes it is the little simple things, the basics.
like when you misplace your car keys when you find them it is ALWAYS in the last place you looked

ROG100

Nice one Greg - master of all. We all need a "Ask Greg" app for our phones.

James Bailey

Good idea Roger ! Need to make it a club like, Good Sam but with $50 annual membership and Greg's normal billing rate of about $2 per minute..... But, But the internet is supposed to be FREE !

Sure is nice of Greg to help those people smart enough to accept it

daveo90s4

Back from a 300 km trip (that's 180 miles for you US bods) with lots of rest stops, coffee stops etc along the way, and the car started straight up every time. So very confident that the fix Greg suggested has done the job.

Great community and this use of the internet and human goodwill is a fantastic mix.

It's 11 pm in Brisbane, Australia. I've got a 7am departure the next day for a club day out. The car is dead in the garage, no spark, no fuel. No time to fix it. I send off a message to Rennliist and go to sleep.

Next morning 1st thing I do is check for any sage replies. Three very helpful replies from 1,000s of kms away (1,000s of miles too), two from persons I've never met, may never meet, and all from people who want nothing in return, but are just being good decent humans giving another human some help.

Then in a space of about five minutes the most simple of all suggestions is implemented and this complicated (to me) piece of machinery is back to life, at absolutely no cost. That meant my fiancee and I had a great social day out, rather than me being under the car trying to nut out the problem. And in addition I can catch the plane at 5am tomorrow morning not having to try to strategise how to get my car fixed in my absence.

I know this is a bit a bit gushy (quite unlike me I think), but the rapid response and assistance made a huge difference to how my day turned out. Thanks.

Dave

GregBBRD

Glad it worked.

Not all solutions are quite so simple, but glad we got lucky on this one and apparently helped make your day better.

I start with the most simple cause and start there. You had multiple things going wrong with one big thing in common.....they all had the same power source. Pretty simple to tell you where to check, first. (And the fact that I've seen this happen dozens of times makes it easier, too.)

Someday someone will need to know a little tidbit that you happen to know.....and you can "pay forward" then.

That's how this Forum works. A lot of really great people helping other great people.

Landseer

Plus in this case the advice came from ^^^the pentultimate 928 expert in the world today! Thanks for posting here Greg.

Mrmerlin

What Chris said^^^

GregBBRD

I think Stan knows more than I'll ever know!

The stuff he comes up with amazes me.