Sportshift ASM Relay Failure
The plating on the ASM relay contacts becomes pitted over time and will ultimately weld together causing the ASM pump to run continuously. You may never notice this while driving because you’ll be focused on the fantastic sound of the exhaust and never notice the ASM pump if you can hear it at all. Then the ASM pump will run for longer than the rated cycle time and burn out. Then next time you get ready to take the car out, you’ll get the dreaded “Unable to Shift” message.
Since the relay is switching an inductive DC load, there is silver-nickel plating transfer from one contact to the other every time the relay is cycled and there is a large fly-back current from the motor when the contact breaks. Eventually, the platting will be eroded and the contacts will weld together. Most circuits protect relay contacts with a flyback diode. For whatever reason, we don’t have this in the Vantage. That omission may be the cause for all ASM pump failures related to the relay. There may be one built into the ASM pump motor but I doubt it.
The solution is really simple. Buy several ASM relays at about $3.50 each and replace the one in the car every year or so. Takes all of a minute or two to change. Throw the old one out or mark it so you don’t re-use it.
If the ASM Pump is over-driven and fails, the repair bill can be quite a bit. Cole European does masterful work on Aston Martins but if you have time and are inclined to work on your own car, you can save a huge amount.
Page updated September 2020