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 evaporative emission (EVAP) diagnostics complete one test cycle. The malfunction indicator lamp (MIL) will illuminate after the EVAP diagnostics complete two test cycles.
• | Operate the vehicle under the condition of the customer's concern. Under high temperature conditions the 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 the EVAP purge is enabled, all fuel vapor release would be eliminated. |
• | Movement of the EVAP pipes or the fuel pipes may help find an intermittent condition. |
The numbers below refer to the step numbers on the diagnostic table.
Perform this procedure in order to determine that no EVAP diagnostic trouble code (DTC) is present.
This test locates fuel leakage in the fuel pipes.
This tests for fuel leaks below the fuel tank fuel level.
This test locates fuel vapors escaping above the fuel level in the fuel tank .
Step | Action | Yes | No | ||||||
---|---|---|---|---|---|---|---|---|---|
Did you perform the Diagnostic System Check-Engine Controls? | Go to Step 2 | ||||||||
2 |
Caution: Gasoline or gasoline vapors are highly flammable. A fire could occur if an ignition source is present. Never drain or store gasoline or diesel fuel in an open container, due to the possibility of fire or explosion. Have a dry chemical (Class B) fire extinguisher nearby. Did you find fuel leaking from the fuel tank? | Go to Step 6 | Go to Step 3 | ||||||
Did you find fuel leaking from the fuel pipes? | Go to Step 7 | Go to Step 4 | |||||||
Important: Ensure that the vehicle underbody temperature is similar to the ambient temperature and allow the surrounding air to stabilize before starting the diagnostic procedure. System flow will be less with higher temperatures.
Important: The GE-41415-50 fuel cap adapter, may not be available for the start of production. Once the J41415-50 is available, start the diagnosis at the fuel fill cap.
Important : DO NOT exceed 15 inches H2O. Did fuel leak from the fuel tank? | Go to Step 6 | Go to Step 5 | |||||||
Important: Ensure that the vehicle underbody temperature is similar to the ambient temperature and allow the surrounding air to stabilize before starting the diagnostic procedure. System flow will be less with higher temperatures.
Important: The GE-41415-50 fuel cap adapter, may not be available for the start of production. Once the J41415-50 is available, start the diagnosis at the fuel fill cap.
Did you locate and repair a leak source? | Go to Step 8 | Go to Diagnostic Aids | |||||||
6 | Replace the fuel tank. Refer to Fuel Tank Replacement . Did you complete the replacement? | Go to Step 8 | -- | ||||||
7 | Replace the leaking fuel pipe. Refer to Fuel Hose/Pipes Replacement - Chassis . Did you complete the replacement? | Go to Step 8 | -- | ||||||
8 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |