General information about testing the fuel tank system
The engine control module (ECM) has a built-in function to quickly check the tank system for leaks. Upon function activation, the control module determines whether the tank system and all of its components and hoses are fault-free or have leaks. Conditions for the test are:
- Engine speed < 3500 rpm.
- Engine temperature 30 °C.
- Normal battery voltage.
- Quantity of fuel in the tank < 60 liters.
- Height above sea level < 2500 m.
- Fuel evaporation is not too high (increased fuel evaporation increases pressure in the tank system).
The amount of fuel evaporation permitted varies depending on the leakage test. Higher fuel evaporation is permitted at 1.0 mm leakage test as compared to 0.5 mm leakage test.
HINT: Evaporation increases under warm conditions. It increases even more when winter fuel is used under warm conditions. Fuel evaporation can be reduced by allowing the fuel to cool. Speed cooling by spraying the fuel tank with cold water.
Other information
- For more information on tank system diagnostics: Leak diagnostics
- Canister purge (CP) valve
- EVAP canister
- EVAP canister shut-off valve
- Fuel tank pressure sensor
- Air cleaner (ACL)
Fig 1: Identifying Canister Purge (CP) Valve, EVAP Canister, Shut-Off Valve, Fuel Tank Pressure Sensor & Air Cleaner (ACL)
- Continue
Refer to Starting the quick test