D3 Intermittent Start Fault

[woodpoleman]

Hi Mathew,

You have the correct relay i.e. grey 370. Mine showed no pitting of the contacts just some heat discolouration at the base of the large high voltage pins. For the sake of £14.75 + vat it's worth replacing. I was at a point where the car would not start and I'd have to wait an hour for the relay to cool down. I'm not an expert but guess the coil was breaking down.

Since being fixed I went into town 5 miles away and once in town started and stopped 5 times calling in at different stores and getting diesel. Car started every time no problem. Beforehand it was like playing roulette and I'd never get beyond three at the most.

Time will tell if it's fixed but it sure seems like it at the moment. Fingers crossed.

Good luck with yours. Peter

[MatthewH]

Thanks Peter. I have purchased a replacement relay for £6.50 including delivery (aftermarket German-made replacement).

Since cleaning the pins on my relay earlier in the week, I've not had the starting problem at all. I think this is just a coincidence as it seems to go in phases - it'll fail to start every morning for weeks and then it'll work fine for a few days.

I'll post an update when I've fitted my replacement - if it all works correctly I'll post the part number of the aftermarket relay I purchased.

[woodpoleman]

Just one last thought. Before changing the relays check your alternator output, battery condition and if a no start try jump leads. After enjoying the euphoria of stopping and starting with impunity I had two fail to starts on the same afternoon last week. The first recovered itself in 10 mins and for the second I called the breakdown service. Each occasion had been preceded by sitting waiting for about 45 mins with the radio on i.e. 2 x 45 min waits over three hours. The battery and alternator were new last year and the battery condition was showing 100% on the MMI - but with jump leads from the breakdown truck it fired up straight away. It's been ok since but for the time being carrying a spare battery and jump leads just in case.

[MatthewH]

Originally Posted by woodpoleman

Just one last thought. Before changing the relays check your alternator output, battery condition and if a no start try jump leads. After enjoying the euphoria of stopping and starting with impunity I had two fail to starts on the same afternoon last week. The first recovered itself in 10 mins and for the second I called the breakdown service. Each occasion had been preceded by sitting waiting for about 45 mins with the radio on i.e. 2 x 45 min waits over three hours. The battery and alternator were new last year and the battery condition was showing 100% on the MMI - but with jump leads from the breakdown truck it fired up straight away. It's been ok since but for the time being carrying a spare battery and jump leads just in case.

Hi Peter,

Yes, that's something I have also noticed (starts first time with jump starts), although I wasn't sure if it was just a coincidence.

I think my battery may also be at fault. It's only 12 months old but resting voltage is around 11.5V after leaving it overnight. It just seems strange that it does eventually start after 5 minutes of turning the key back and forward.

My replacement relay arrived today so I'll fit that and see how it goes. Planning to book my car into Halfords for a free battery load test to prove the battery is bad - if this is the case I can replace it under warranty.

[woodpoleman]

I had an A6 that knocked out 3 batteries in about 5 years. There was a constant low power drain on the battery but Audi never found out what caused it. Don't now know if this is something similar again?

[woodpoleman]

Here we are again not yet fixed despite all the (false) hopes.

To recap replaced Entry & Start Authorisation (J518), Ignition Switch plus battery and recode (Audi refused to recode J518 because non VW battery (Jun 16), Starter Relays J329 (370), J53 & J695 (both 381) Jan 17, Energy management Control Unit (J644) Apr 17, another battery (May 17). My garage say battery faulty Audi say battery ok.

Been limping along with spare battery and jump leads in the boot. Also on a no start (in a petrol station) turned ignition off and on continuously did manage to start. Fault has now become more prominent and jump leads not doing it. Had a couple of occasions on very hot days when wouldn't start from cold.

Away from home this last weekend. Very hot weather outbound journey no start after a pit stop jump start no good kept trying and started. Next day very hot car parked with front facing sun all day would not start at all until the evening when cooler. Moved the car into shade for next morning to come home started ok drove home 4 hours non stop. At home tried an immediate restart no joy.

Given that the front of the car was in the sun all day could this be more electronic rather than electro-mechanical maybe the Engine Control Unit, Electronics Box or Power Relay J271 all located in the plenum chamber?

Any help will be gratefully received. Thank you.

[North2007]

Did you get it fixed Woody?