A bit of a rough start
Discussion
Looking for some input and maybe confirmation of my findings.
I picked up an 07 DB9 with 10k miles on it... however its a flood car so, it has its own set of issues. When I got it, the car would not run, just crank and act like the battery was low or something was shorting. The instrument cluster had a CEL flickering and turning on and off with the sound of a relay(something?) clicking under the hood. Some of the interior worked but it was mostly in pieces. turn the key over, nothing, flickering red start light is about all I would get. No gear select lights or anything either.
SO... I get it home and begin to diag it. The previous owner had hacked the CEM up but.. all wires are properly sorted and going to the right connectors as far as I have been able to tell. I was getting a lot of CAN communication and short errors through my scan tool. Did continuity checks on the wires, ohm checks, and everything seemed to check out. Any time I turn the car to start, the throttle bodies start to hum and click. and that's all I really get from the motor. After countless hours of checking wires... everything seems fine with no shorts. Finally, I get an idea to check PCM by PCM... I pulled the relay for PCM A and BOOM, all the interior lights come on, CEL stop flickering and when I push start, it cranks normally! With that being said, I swapped the PCMs and success! The gear lights are on, the start button is steady red and looks like shes getting better. Except, the throttle bodies are still buzzing and clicking. The noises swapped sides with the PCM swap but they are still acting up. I decide... might as well try and see if it runs, After a few cycles of cranking she came to life.
Here is where I am at. She will start, go into gear, and otherwise seems okay other than the codes being thrown and zero response out of the pedal. There are some other issues like a leaking exhause gasket and a whining noise from the trans but... those are issues I will get to.
Does anyone have any input on what it could be that causing the TB to act the way they are? I suspect the PCM that was PCM A when it wasnt starting is bad due to swapping it to the other side and the car starting.
Happy to provide any additional information that I can that might help in getting this amazing car back on the road.
Codes are:
P2139: Throttle/pedal pos primary to secondary correlation (I did the checks, voltage seems okay)
P1656: CAN link PCM/PCM Circuit/Network ????
P0705: Transmission PRDN Request Invalid. CAN and Serial Line Invalid
P1797: CAN TCM/ECM Position Circuit Malfunction (will eventually clear)
P0863: Serial Backup Line Timeout
P1639: Veh ID block corrupted not programmed (this one will come and go)
I picked up an 07 DB9 with 10k miles on it... however its a flood car so, it has its own set of issues. When I got it, the car would not run, just crank and act like the battery was low or something was shorting. The instrument cluster had a CEL flickering and turning on and off with the sound of a relay(something?) clicking under the hood. Some of the interior worked but it was mostly in pieces. turn the key over, nothing, flickering red start light is about all I would get. No gear select lights or anything either.
SO... I get it home and begin to diag it. The previous owner had hacked the CEM up but.. all wires are properly sorted and going to the right connectors as far as I have been able to tell. I was getting a lot of CAN communication and short errors through my scan tool. Did continuity checks on the wires, ohm checks, and everything seemed to check out. Any time I turn the car to start, the throttle bodies start to hum and click. and that's all I really get from the motor. After countless hours of checking wires... everything seems fine with no shorts. Finally, I get an idea to check PCM by PCM... I pulled the relay for PCM A and BOOM, all the interior lights come on, CEL stop flickering and when I push start, it cranks normally! With that being said, I swapped the PCMs and success! The gear lights are on, the start button is steady red and looks like shes getting better. Except, the throttle bodies are still buzzing and clicking. The noises swapped sides with the PCM swap but they are still acting up. I decide... might as well try and see if it runs, After a few cycles of cranking she came to life.
Here is where I am at. She will start, go into gear, and otherwise seems okay other than the codes being thrown and zero response out of the pedal. There are some other issues like a leaking exhause gasket and a whining noise from the trans but... those are issues I will get to.
Does anyone have any input on what it could be that causing the TB to act the way they are? I suspect the PCM that was PCM A when it wasnt starting is bad due to swapping it to the other side and the car starting.
Happy to provide any additional information that I can that might help in getting this amazing car back on the road.
Codes are:
P2139: Throttle/pedal pos primary to secondary correlation (I did the checks, voltage seems okay)
P1656: CAN link PCM/PCM Circuit/Network ????
P0705: Transmission PRDN Request Invalid. CAN and Serial Line Invalid
P1797: CAN TCM/ECM Position Circuit Malfunction (will eventually clear)
P0863: Serial Backup Line Timeout
P1639: Veh ID block corrupted not programmed (this one will come and go)
Your a very brave man to take on a DB9 with flood damage, they have electrical niggles at the best of times!!
All depends on how high the water went to in the car, trouble is there are lots of computer modules scattered about and with the ZF gearbox i'm hoping your problems will not be too bad.
If the CAN bus system is getting corrupted signs from a faulty module you will get lots of problems.
I 100% recommend you contact Mike at Bamford Rose as he will help you alot on the fault codes and/or repairs required, he also has AMDS and can independently flash modules away from the dealer network to enable a module to hopefully work.
Fingers crossed and let us know how you get on.
All depends on how high the water went to in the car, trouble is there are lots of computer modules scattered about and with the ZF gearbox i'm hoping your problems will not be too bad.
If the CAN bus system is getting corrupted signs from a faulty module you will get lots of problems.
I 100% recommend you contact Mike at Bamford Rose as he will help you alot on the fault codes and/or repairs required, he also has AMDS and can independently flash modules away from the dealer network to enable a module to hopefully work.
Fingers crossed and let us know how you get on.
Nothing to do with me but I noticed this post in another thread and I’m guessing it was meant for you in this thread... so see below... as already mentioned seriously water damaged cars can be an ongoing nightmare, so I wish you luck in sorting things 
AM4884 said:
There is so little DIY data on these cars that it's mostly spitballing... I am an accomplished spitballer...
Having rebuilt the engine in a DB9, I have spent considerable time under my lift, under the dash, and around the car. There are lots of ground points, and lots of effort to remove ground errors (additional wiring as an example).
All of the ground points in the engine bay, and in the rear showed significant corrosion on my 2006 DB9. That would be the first place I would start, along with a fresh battery (some say pointing the car north will help. Others say Abelour....
There are 12 grounds on the firewall (6 on each side, 3 high, 3 low), plus the strap to the torque tube to the body. Similar in the rear. I would be sure to renew each of the ones that underwater. The upper 6 are protected - the lower ones not so much.
Oh, and if you are doing this in the US, then definitely point the car towards Frankfort, KY - worked for me...
Having rebuilt the engine in a DB9, I have spent considerable time under my lift, under the dash, and around the car. There are lots of ground points, and lots of effort to remove ground errors (additional wiring as an example).
All of the ground points in the engine bay, and in the rear showed significant corrosion on my 2006 DB9. That would be the first place I would start, along with a fresh battery (some say pointing the car north will help. Others say Abelour...
.There are 12 grounds on the firewall (6 on each side, 3 high, 3 low), plus the strap to the torque tube to the body. Similar in the rear. I would be sure to renew each of the ones that underwater. The upper 6 are protected - the lower ones not so much.
Oh, and if you are doing this in the US, then definitely point the car towards Frankfort, KY - worked for me...
P2139. In live data on the scan tool, key on and note the readings of the accelerator pedal. Is one at close to 5v and one close to 0v? Press the accelerator pedal slowly and one should drop evenly while the other rises at the same rate. At all times the total of the 2 readings will be very, very close to 5v.
You've probably already checked but the link may help.
https://www.dtcdecode.com/Ford/P2139
You've probably already checked but the link may help.
https://www.dtcdecode.com/Ford/P2139
Well, good news... Got the car started and idling with some additional issues. Changed out the PCM and my throttle body issue stopped. Now, it will run and idle just fine with one issue... Its very sluggish to respond to throttle input but the main issue I am having is that once it gets to about 4k RPM or I hold idle above 2k rpm it seems to start missing and losing cylinders. It will run very rough and eventually stall. I can get it to drive under its own power but too much load and it does the same thing, like its shutting down... I'm thinking it might be fuel but I don't see any drops in pressure.
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