ECU / Key not unlocking the car

[juddcampbell]

I am using the crystal key to lock the car and when I return a few hours later the remote will not unlock the car. I have changed the battery in the crystal key but it still would not unlock the car. I also attempted to use a valet key. it did not work either.

I had my wife drive the door key down to my work and it opened the door setting the alarm off. The crystal key and the valet key would drive the car without issue. Strangely only 10 min after driving the car I shut it down and it locked and unlocked the car just fine.

The car was parked in the sun from noon - 6pm and it was 90+ deg that day. The top was up.
Once the car was started the top went down and the gauges worked fine the entire time.

Today I drove the car again and this time I parked with the top down for 2 hours while I had lunch. I used the remote to lock it and when I returned it would not unlock the car. I had to use the mechanical key which set off the alarm then use the crystal key.

I am thinking I have an issue with something when the car overheats. any hints?

[Gday2]

If it happened at the same place look out for a radio controlled construction crane, it happened to me with an other car that the radio control of the crane jammed the remote of the car. If you parked on different locations it seems to be your guess of overheating of the receiver, see the friendly guy.
Cheers
Christian

[juddcampbell]

different location for each instance. also, I have been parking at work in the same spot for 4 months. this is the first time it has been an issue.
The dealer is 3 hours drive away. I will be attempting this repair myself.

[rovcallum]

It all sounds a bit random.... that could be the car battery then!
Something to think about.
Keep us posted when you get it resolved.

[juddcampbell]

Yes, the random bit concerns me. The battery tests fine. I will monitor the charge level as I suspect it could be the alternator. when I put the trickle charger on the car it always shows low. perhaps my alternator output is less than optimal.

[juddcampbell]

I took my car to my local indy mechanic this morning. He hooked the computer up to the car and found that there was a fault logged showing "Central module CAN low" with the key on and the engine not running it showed 6V going to it. The battery was outputting 12.1V at the time so I am thinking I have a loss along the way or the module is bad. Going to continue to investigate

[juddcampbell]

here is a link with more information about the CEM

https://www.6speedonline.com/forums/aston-martin/3...

I don't see a 2009 CEM listed for sale on Scuderiacarparts.com. I will have to call if that ends up being the issue.
https://www.scuderiacarparts.com/diagram/astonmart...

[yourtheguy]

Hi my 07 V8V played up on the locking and unlocking a while ago, turned out to be the battery in the alarm sounder.
New sounder fitted problem solved, about £140 for part and about an hour to fit.

[Dobie177]

Out of interest, when buying a used AM (I have a 2012 model in mind), should the car come with 1x or 2x the glass ECU keys. From what I've searched, im assuming 1 glass key and 2 plastics???

[rovcallum]

One glass ECU key plus one cheap ECU key, plus a regular key which only opens the doors.

[hashluck]

Though you could optionally purchase a 2nd glass key but certainly the below is that supplied as standard

[Dobie177]

Thanks gents - good to know.

[Gday2]

I don't know if this helps but I remember that there was a service bulletin about bad ground studs on the V8V. It affected VIN range C00001 - C00276 and was Powertrain to chassis earth lead integrity
Cheers
Christian

[juddcampbell]

Gday2 said:

I don't know if this helps but I remember that there was a service bulletin about bad ground studs on the V8V. It affected VIN range C00001 - C00276 and was Powertrain to chassis earth lead integrity
Cheers
Christian

Is there a handy list of ground locations for the DB9 Volante?

My car has one crystal key, two plastic valet keys, and one door key to manually unlock it. I hate that I now need to carry the door key and the fob.

[Gday2]

Sorry Iv'e only got all stuff from AM technet for my V8V, Anyhow technet is great and worth the money, If I remember correctly it was 70£ for a day.

[rovcallum]

I just downloaded a Workshop Manual 2005-16 (Issue 6) from fleabay for about £9. It was 115 Mb and seems to have loads of info I might possibly require. Page 760 has info on earths.

Worth a go, although I think AM techinfo with all the service bulletins and extra info will cover absolutely everything...... for £70 a day.

[juddcampbell]

Well, the car worked well for just over a week without giving issues. Once again I had locked the car and when I attempted to use the remote to unlock it there was no response. I had to use the manual door key again (which I now carry with the crystal key daily)
I will need to start checking those grounds