A faulty vapor leak detection pump will permit fuel vapors to escape into the atmosphere in and around your vehicle
that could lead to an explosive situation if a leak is present. This device is part of the evaporative emissions
control system that runs checks on the many different connections where fuel is present. When the vapor leak
detection pump is not working properly or not working at all, a vapor leak as big as the fuel cap being off to a
small pin hole leaking fuel will not be noticed by the onboard computer leading the improper amount of fuel being
dispensed to the fuel injectors.
The vapor leak detection pump became a mandatory component on vehicles in the US back in 1996. Its main purpose is to detect any vapor leak on the fuel system no matter how large or small it is. When a leak is detected an error code is sent to the onboard computer and the warning light on the dashboard will become illuminated. The vapor leak detection pump can also send an error code if one of the passageways for the fuel or fuel vapors becomes blocked. This device operates with a self-diagnosis program and is constantly checking for a vapor or fuel leak when the vehicle is being operated.
The vapor leak detection pump on most models located in the engine compartment and mounted near the charcoal canister used for trapping the vapors in the fuel system. The replacement procedure for the vapor leak detection pump requires that the battery be disconnected before it commences to reduce the chance of a fire. All of the lines must be removed from the pump before the mounting bolts are taken off and the pump replaced.