V12V throttle pedal on and off

[chrzesm]

My colleague owns Vantage V12 MY 2017 and he experiences weird throttle issue. Very often, when he starts engine, the throttle does not work at all. After several restarts the throttle pedal starts working and it works until he shuts the engine off. When driving all is fine. The car does not have OEM tracker/immobilizer. All connectors double checked and they are ok. Any suggestions more than welcome. Thank you!

[Ex Boy Racer]

Is it a manual?

[leman600]

OBD reader could assist with throttle pot reading. Should see that with ignition on and moving throttle.
No expert here but has he tried sport mode as this gives a little more of a clue to think on. (different map) Also try starting with throttle fully depressed. (won't start then throttle active) That could show if the throttle is live on the network at that point.
Good luck.

[Emilio Largo]

leman600 said:

Also try starting with throttle fully depressed. (won't start then throttle active)

No ignition inhibit feature on the V12 Vantage S. If throttle pedal DOES work, this will do the engine no good.

[phumy]

Emilio Largo said:

leman600 said:

Also try starting with throttle fully depressed. (won't start then throttle active)

No ignition inhibit feature on the V12 Vantage S. If throttle pedal DOES work, this will do the engine no good.

If it has the later Bosch ECU the throttle pedal to the floor will not inhibit the engine from starting, as Emilio says above (V12 VantageS)

[leman600]

Sorry for the duff throttle fully depressed suggestion. I thought that was standard.
Certainly sounds a strange one.
What has been checked already apart from connections?

[chrzesm]

It is Sportshift and yes, it is Bosch. Slave ECU reports vehicle communication bus B error. Hmm, it seems to be a connection related issue (dry contact in ECU)? Could be difficult to diagnose...

[leman600]

Like you say could be difficult.
The dry joint isnt a different joint once running and reliable but has your friend mentioned if it exhibits the fault once stopped and still warm or if he returned to the car after some time.
Does your obd reader see the pot moving each time power is cycled?
A dealer could have a field day with this one or it could be easily sorted with experience of similar.
Good luck.

[chrzesm]

leman600 said:

Like you say could be difficult.
The dry joint isnt a different joint once running and reliable but has your friend mentioned if it exhibits the fault once stopped and still warm or if he returned to the car after some time.

The fault exhibits only when the car is cold :-( When warmed up, all works fine. I think ECU swap is the way to go. I sense ECU replacement will be required :-(.