My 2003 Cabriolet starts with full battery power most of the times I start the car, but every now and then I turn the key and nothing happens. I will wait a minute or so, possibly less and it will start up with full battery power again. The battery has never seemed weak when starting the car. I am not sure if the other electrical functions work when the car won't start, but I think they are all fine.

This leads me to wonder if this car might have an automatic cut-off mechanism for the ignition that would be triggered by something else. I can't determine this, the first time it happened I checked my oil and it was slightly low. I topped it off and it started perfectly. As time has gone on and this happens every 20th start or so, I realize that this was likely a coincidence.

Please help me diagnose the intermittent ignition problems if you could. I would certainly appreciate hearing what others have done.

Thanks in advance for your help.

Kurt

 

Here are four quick thoughts on potential causes for occasionally not starting.

You probably know this, but the clutch needs to be COMPLETELY depressed before the car will start. If it is even 1/4" short of being completely depressed the car will not start.

It could be your ignition switch is starting to wear out. This is a common, well documented weak link on the 996.

Check the battery cables to make sure they are not loose.

Have the battery checked out at Autozone (or similar place). Most will do this for free.

Make sure yo let us know what the solution ends up being to the problem.

 

Thanks Tim. I will do that.

One item before I mess with the battery is the radio security code. I bought the car two years ago and didn't get the code. Is there a simple way I could retrieve this? Is it based on the serial number in some way? I hesitate disconnecting the battery until I have this security code handy.

Thanks for your time and I will let you know what I find.

Have a nice weekend.

Kurt

 

Kurt,

You do not need the radio code. It was programmed into the DME for the 2003 and 2004 model years. If you disconnect the battery you will lose the preset radio stations. I think you may also lose your memory seat condigurations if you have memory seats, but that is about it.

 

If you have the original battery...it is over...get a new one.

 

Yes, the battery is original.

Nice Cab Statman.

Kurt

 

I am having the same problems with my car, crank it and the starter doesn't seem to crank. My battery is new since december of 2008, it's a porsche OE battery. Anyways, how do I diagnose if the ignition switch is the problem?

 

Also would this be the part?
http://e-partssales.com/Merchant2/me...AUDI4A0905849B

 

When you say nothing happens, Does the dash light up and thecar not crank. I have changed alot of ign switchs and only seen one or two that caused a intermittent no start. 99.9999999% of the time its no head lights no ac and cluster doesnt shut off. Is your car a stick ot a tip?

To tsi, yes that is the old style switch, but if you have a new style lock housing that switch will not work, also you should consider changing the whole housing should prevent futher issues ( have seen very few failures of the new style housing)

 

99firehawk: my car is an 02 so I think that's the old switch no? my car has all dash light, the oil meter runs, radio runs hvac runs, so everything electrical runs but when I crank it to ignite with the key, the starter doesn't crank, there is no ticking noise indicating the battery is to low to crank the starter. My volt meter reads a little over 12 volts when this happens

 

tsi: Look under the dash on the drivers side, on the clucth pedal you will see a square grey switch with 2 individual wires going to, The next time the car will not start un plug these wires from the switch and install a 10 amp fuse between the wires. If the car starts you need a new clutch saftey switch (the grey square one) Its held in by 1 little phillps screw

 

Had intemittant start issue and turned out to be a bad key head/immobilizer (see my post in December 2008). Use your other key and see if problem disappears. If so, get a new head (for $130 + programming).

 

I have a similar problem, it always starts but sometimes after I shut the car off for about 5 mins (eg. to the bank machine) get in and try to start it again it give me a very weak start. Battery seems find, no problems on starting in the morning. Seems really strange to me.

 

jake, you would need to check the starter draw while hot, either a starter dieing or you have a battery cable (+ or -) that is loose or developing high resistance.

 

Any way to check key head if you only have one key? Dealer didnt have both keys for my car