Fuel Tank Leak Detection Function
- The Fuel Tank Leak Detection Module -GX36- -1- is used to check the tank ventilation system -3- for the smallest leaks (less than 0.508 mm diameter) and small leaks (less than 1.016 mm diameter). It consists of an electric air pump, a change-over valve, and a reference leak with a diameter of 0.508 mm, which is only used for reference purposes.
- The fuel tank system is checked for leaks by comparing the actual current draw for the air pump with the current draw that is present when the system is operating with a standardized reference leak.
- For the reference measurement, the air pump is switched on briefly while the change-over valve is closed and the current draw of the air pump motor is measured while fresh air is pumped from the air filter -2- through the reference leak.
- Before starting diagnostics, the Fuel Tank Leak Detection Module -GX36- should be heated for a set period of time to prevent moisture from condensation.
If the fuel tank leak detection system has detected a leak, the fuel system must be checked for leaks. Refer to FUEL SYSTEM, CHECKING FOR LEAKS .