Fuel Tank Leak Test

FUEL TANK LEAK TEST

DESCRIPTION
The fuel tank leak test is used to locate any fuel or fuel vapor escaping the fuel tank area. Fuel vapors escaping above the fuel level will be detected when the EVAP leak diagnostic completes one test cycle. the MIL will illuminate after the EVAP leak diagnostic completes two test cycles only when a condition is detected.

DIAGNOSTIC AIDS
- Operate the vehicle under the condition of the customers concern. Under high temperature conditions fuel vapors may increase to the point of EVAP canister vapor saturation. Fuel vapors would then be released into the atmosphere. Once the engine is running and EVAP purge is enabled, all fuel vapor release would be eliminated.
- Movement of the EVAP pipes or fuel pipes may help find an intermittent condition.

TEST DESCRIPTION

Steps 1-4:

Steps 5-6:

Steps 7-8:

1. This step determines that no EVAP diagnostic DTC is present.
3. This step tests for location of fuel leakage in the fuel lines.
4. This step tests for fuel leaks below the fuel level in the fuel tank.
5. This step tests for a location of fuel vapors escaping above the fuel level in the fuel tank.