Hi all,

I just got another db9 after selling my 06 with over 80k on it. Anyways the new 08 I got seems to sporadically pop up with a gear box error when shifting to park when the vehicle is completely stopped. I remember on my 06 this happend a few times as well and the dealer even told me the switch contacts sometimes cause this. A restart would always cure the error or just ignoring it would work. I ran the car from P R N D about 10 times after seeing the error and I was unable to reproduce it.

I was wondering if there is anything to be concerned about with this. Perhaps I will check the battery as it is original, it seems to crank strong but I know the canbus is very sensitive to low voltage.

Thanks!

 

I've had this show up on my '06 DB9 a few times, but usually when starting out. Then I read somewhere (AMOC I think) that you have to press the buttons firmly in the middle to get a solid contact.

I've since changed my habits. I always wait for the full system check to complete before hitting the start button, and I always hit the gear selector buttons smack-dab in the middle with some conviction. I also use the paddles more than the buttons. Haven't seen any faults since.

BTW: Just by turning the engine off it automatically selects "Park". You don't really have to press the button.

 

I found that I can replicate the fault by pressing any button lightly. I guess there is a problem with the internal contacts of each button. If use the paddle shifters there is no errors. But today after being in manual mode, I pressed D, (not hard enough) and the car went into neutral, said "GEARBOX FAULT NO DRIVE" so I had to coast and re engage drive . Has anyone heard of the buttons just going bad like this. The car has 13k miles, my 06 had 80k and wasn't this peculiar! I am about to take the center stack off tommorow.

 

Mine only ever happened in the garage. I'd be getting it properly checked if it failed at speed. Are you planning on shooting some contact spray in there once you've got it opened up? Have you checked on Pistonheads & AMOC for solutions?

I've promised myself that the next time I popped that panel off I'll swap the position of the buttons so they make sense for LHD (D N R P).

 

Yes, I would say a switch or wiring is at fault, mainly the "P" switch is the common, if you press the "P" lightly and this trans fault error msg ocurs..if it's a concern the switch would need to be diagnosed..I've also had the wiring at fault to the switch. This can be easily diagnosed by the dealer by looking at the switch voltage in datalog while being pressed lightly and firmly

 

Thanks for the responses. I am leaning towards thinking this is a wiring fault, because this actually occurs with every button P R N D if it is not pressed super firmly. Irish, is there a specific area where the wiring fault occurs?

 

Yvr, I checked on pistonheads and amoc as well. It seems there was only a few complaints on this topic essentially stating what you wrote here. I tried to squirt contact cleaner into the switches but that didn't seem to make a difference.

 

Don't be fooled, you can actually have all switchs go out on you, a nice voltage spike can fault the switchs..the voltage range is very tight and just a few mV's outside that range you will get the error msg and a fault stored for the switchs..

For the wiring, I have had 3 cars(early DB9's, 2005-2007) with the wiring issue, when you take out the center front ski slpoe you will see the harness turn behind the dash plastic frame section, harness on all 3 cars had chaffed on the edge of the plastic dash framed section, cut/soldered/glue filled shrink tubed damaged harness wires..never had a concern with the 3 cars again. **knock on wood*

 

hi,

can you help :-
i read your post and i wondered if you had a digital pic of the wiring damage ?...when you say "you will see the harness turn behind the dash plastic frame section, do you mean directly behind the switches ? or ?

the problem with mine is i cannot get it to come out of park, e.g press reverse or any of the other PRND Switches no response.

any help would be much appreciated

cheers

 

I don't have an image of it, you can't miss the harness though. When you remove the ski slope veneer for the switchs and center vents, you will see the harness loop behind the dash plastic frame and metal cast braces. The harness can get chaffed on the metal cast section, and can get pinched by the tie wrap clips that could cause to much resistance.

Can you use the paddles to shift into neutral or and of the drive gears? ..if you can't, might be another concern

 

thank you for the further info...yes the paddles switches engage gears ok...also the fault does not produce any error messages on the dash and is intermittent fault !.a further question. Should the LED in the reverse switch be a Red led as opposed to the Yellow in the other switches ?
many thanks for your advice on this.