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. |
• | Moving 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 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 | ||||||||||
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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 7 | Go to Step 3 | ||||||||||
Did fuel leak from the fuel pipes? | Go to Step 8 | Go to Step 4 | |||||||||||
Important : DO NOT exceed 15 inches H2O. Did fuel leak from the fuel tank? | Go to Step 7 | Go to Step 5 | |||||||||||
Important: The fuel tank may need to be partially lowered. Refer to Fuel Tank Replacement .
Did you locate a fuel or vapor leak? | Go to Step 6 | Go to Diagnostic Aids | |||||||||||
6 | Repair the system as necessary. Refer to Fuel Hoses/Pipes Replacement - Filter to Tank Did you complete the repair? | System OK | -- | ||||||||||
7 | Replace the fuel tank. Refer to Fuel Tank Replacement . Did you complete the replacement? | System OK | -- | ||||||||||
8 | Replace the leaking fuel pipe. Refer to Fuel Hoses/Pipes Replacement - Filter to Tank . Did you complete the replacement? | System OK | -- |