I'm working on a 2005 DB9 with a missing left ECM communication.
Key is not recognized either.

Anyone with a diagram or previous experience in a similar scenario?

Thanks!!

 

I have restored communication with BOTH ECM's... but still have a issue.

ERROR KEY and the temp gauge goes ALL THE WAY UP..

Any ideas??

Error codes are as follows:
BANK 1

B1600 No key code received
P0705 Transmission range sensor circuit malfunction
P1000 System Check not completed (its nothing..)
P1797 CAN transmission control modul to engine control module malfunction. (This one worries me..)

 

This looks like I'm talking to myself..

I have done some more test on this car.
I disconnected the transmission plug to check CAN lines. I find out that there is NOTHING on pin #2 (CAN L) and pin #6 (CAN H)
No voltage as expected (2.4 + V) or ohms reading..

Checked also pin #13 / 16 for ground Its OK

Checked pin #14 for POSITIVE (perm) its OK

So, my question is..... who's the module before TCM ? I want to check the transceiver output on that module.

Any one with this info?? thanks!

 

Engine control module is where it comes from. What is the story beforehand? Crash car? Or just some rodent damage from storage?

 

I don't know exactly the past story... Car was shipped to California from Florida with NO START condition.

I'll check the CAN at the ECM to see what's the readings. I disconnected LEFT (B) ECM, so I'm going to also ceck continuity from ECM to TCM pins.

Any sugestion?? Thanks

 

What did you find ?

 

Long time of radio silence, guessing it's not running and there's a story we shall never know.

 

This is my biggest worry with these cars. As things like ECUs start to fail, in order to pass emissions regulations we would need the same ECU. We couldn't just wire in a Motec or Haltech unit and drive the car legally in many places even if tail pipe emissions still passed.

 

We had an ECU issue on the Gen 1 Vanquishes. The team tracked the issue back to a failed processor. Long story but the failure was heat related so we froze the ECU (PTEC) then went round warming up chips until we saw which one had failed. Bought all the chips left -(Chip obsolescence is a big issue to worry about) and fitted them and reflashed. Problem solved.

We have managed to do the same on the Convertible Roof Modules and are working on the door modules currently.

In the car mentioned in this thread this is almost certainly a wiring issue. However, we have seen more than one car where an independent or amateur has used probe pins that are too large and have created disconnects that need to be fixed.

We have yet to see a failed DB9 ECU. Not saying they don't exist but the ECMs appear to be robust. CEMs less so.

 

The CRM is pretty cavalierly mounted over the left rear wheel in the DB9. There were earlier suggestions of potting the electronics to increase the robustness to vibration or relocating the module to inside the trunk. My ECM issues all trace back to the wiring harness hanging below the ECMs and having the wire distend from the connectors. Shoving the wires back in, and providing additional support has seemed to cure the issues where suddenly 4-5 different unrelated codes pop up. As a kit car owner/builder I sadly recognize some of the manufacturing techniques employed by Aston Martin... Look great outside, but where only your mechanic will see not so much. Akin to a Lamborghini and very much unlike a Acura NSX or Porsche.

 

The damage to the CRM units is not physical damage as in water or dislodged chips etc.
It is physical failure inside the silicon.
I don't think Potting the Board would make any difference.

 

Pretty standard in aerospace to pot the electronics to insulate the electronics from shock and vibration. It's exactly to prevent this type of failure that we pot up boards.

 

Would potting up prevent a microprocessor from failing due to temperature?
In the case of CRM modules they fail when hotter, work when colder.

 

Yeah, the issue you highlight is the difference in expansion rates of the boards/pads/solder. It causes the solder bonds to fail, both inside the chip (harder) and to the pads (easier). Potting it all makes it all work at one temperature and expand/contract together. The downside is that it's a PITA to dig the board out of the epoxy if you need to get back in.

 

Can the temperature above the L Rear wheel, which is where the CRM module is, get sufficient to cause this breakdown inside the silicon chip itself?