Checking EVAP system for leaks
- Clamp off LDP outlet (EVAP side) - 1 - using special tool Hose Clamps Up to 25mm dia. 3094 or equivalent.
CAUTION:
Clamp only soft rubber lines when isolating a leak. To avoid risk of damage, never clamp hard plastic lines!
- Turn control valve from "Hold" to "Test".
- Allow fuel system to pressurize.
NOTE:
- Fuel system pressurization depends on volume of fuel system and amount of fuel in tank.
If fuel system pressurization does not stabilize:
- Verify that all fuel system outlets have been sealed before continuing.
NOTE:
- Any flow shown on flow meter indicates a leak. Flow below flow meter flag set at vehicle leak standard may indicate a sporadic DTC.
If flow meter on tester registers flow near or above pre-set pressure:
- Clamp off hose leading from EVAP canister purge regulator valve N80 to intake manifold.
If flow stops:
- Replace EVAP canister purge regulator valve N80 and repeat test before continuing.
If meter indicates no flow after test:
- Perform quality check and return vehicle to customer.
If flow continues:
- Use smoke generator trigger to charge fuel system with smoke again.
- Inspect complete EVAP system for escaping smoke.
NOTE:
- It may be necessary to move, twist, or wiggle EVAP components around to reproduce leak.
If leak cannot be found using smoke:
- Locate leak with ultrasonic tester.
- General search: tester only
- Localized search: tester with extension wand (left)
If leak cannot be located:
- Disconnect and plug or clamp shut EVAP lines to isolate fuel tank using special tool Hose Clamps Up to 25mm dia. 3094 or equivalent before continuing.
CAUTION:
Clamp only soft rubber lines when isolating a leak. To avoid risk of damage, never clamp hard plastic lines!
If flow stops:
- Reconnect EVAP lines and search area that was isolated.
When leak has been located:
- Repair leak and repeat EVAP system test.
NOTE:
- Because leak may be at top of fuel tank, it may not be possible to locate through fuel pump/sending unit access plate.
- Lower fuel tank if necessary to locate leak.
CAUTION:
Do not return vehicle to the customer without having performed a proper diagnosis and repair.