Vanquish Idle Surge

Has he tried disconnecting the battery for a few hours (overnight) and then re-connect. Turn off all equipment (a/c, electrics), without touching the gas start the car and let it run for 5-10 min while the computer re-learns. Hopefully, it will help.

 

Same can be accomplished in the Vanquish using the battery disconnect in the trunk (upper right by the charging port) and the reset button behind the passenger seat. Make sure you move the passenger seat up BEFORE hitting the battery disconnect as otherwise the electric seat will be disabled and it's a ***** to get to the reset button.

Also ask if he has had ignition coils replaced on the car. They were a weak spot on Vanquishes and many people didn't replace them as they are $$$. The replacement units seem to be a good bit better. Both the parts and the labor cost for the swap is unpleasant but necessary.

There is also great advice on the Aston Martin Owner's Club forum if he wants - www.amoc.org. I have also had good luck just sending an e-mail to Aston Martin Works Service in England with questions. They take a day or so to get back to you but are very helpful with things to try.

 

If he needs help and is local have him call me