The fuel tank leak test is used in order 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 completes one test cycle. The malfunction indicator lamp (MIL) will illuminate after the EVAP diagnostics completes 2 test cycles.
• | Operate the vehicle under the condition of the customer's 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. |
• | Test for fuel leaking in the following locations: |
- | The fuel tank |
- | The fuel feed and return pipes |
• | Test for fuel vapor leaks in the following locations: |
- | The fuel tank, fill limiter vent valve and rollover valves |
- | The fuel fill pipe, hose, and fuel fill cap |
- | The fuel sender housing and seal |
- | The fuel tank pressure (FTP) sensor seal |
- | The EVAP vapor pipe |
• | Movement of the EVAP pipes or fuel pipes may help find an intermittent condition. |
Perform this procedure to determine that no EVAP diagnostic DTC is present.
This test is to locate fuel leakage in the fuel lines.
This tests for fuel leaks below the fuel tank fuel level.
This test is to locate 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 |
Important: Before performing this procedure, place a dry chemical (class B) fire extinguisher near the work area.
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 in H2O. Did fuel leak from the fuel tank? | Go to Step 7 | Go to Step 5 | |||||||||||
Important: You may need to partially lower the fuel tank. Refer to Fuel Tank Replacement .
Did you locate a fuel leak? | Go to Step 6 | Go to Diagnostic Aids | |||||||||||
6 | Repair the system as necessary. Did you complete the repair? | System OK | -- | ||||||||||
7 | Replace the fuel tank. Refer to Fuel Tank Replacement . Did you complete the repair? | System OK | -- | ||||||||||
8 | Replace the leaking fuel pipe. Refer to Fuel Hose/Pipes Assembly Replacement . Did you complete the replacement? | System OK | -- |