Evaporative Emissions System: Testing and Inspection: Diagnosis and Testing
Leak Detection Test, Performing
Special tools, testers and auxiliary items required
• Hose Clamps Up to 25 mm Dia. (3094)
Check the fuel tank lead diagnostic system in Guided Fault Finding using a vehicle diagnostic tester.
Checking the Fuel Supply and Fuel Tank Ventilation System for Leaks
• The following describes individual areas in the fuel supply and ventilation systems where leaks are possible. After repairing a possible leak, perform a leak test to ensure that leak was successfully repaired.
• Secure all hose connections with hose clamps of the same type as those equipped by the factory. Refer to the Electronic Parts Catalog (ETKA).
• Replace seals and gaskets when performing repair work.
- Turn off the ignition.
- Check whether the fuel filler cap of the fuel tank was completely sealed for the test.
- Check whether seal of fuel filler cap was damaged or crimped. Replace if necessary.
- Remove left seat cushion in 2nd row and right seat frame in 2nd row.
Risk of injury.
• Wear safety gloves.
- Cut the floor covering along the perforation - arrows - on the left and right sides with a carpet knife - 1 -.
- Fold the floor covering to the side - arrow -.
- Remove nuts - 1 to 4 - and remove right and left locking flange cover.
• Observe installation notes for locking flanges => [ Installing ] Suction Jet Pumps.
- Check whether seals under locking flanges are OK and lock rings are properly tightened on the fuel tank. Also check the fuel line connections.
- Visually check all wires and hose connections of fuel supply system and replace leaking lines, for example:
• Line from EVAP canister to Evaporative Emission (EVAP) canister purge regulator valve 1 (N80)
• Line from fuel tank to EVAP canister.
• Tank ventilation system lines.
• Seal between EVAP canister and Leak Detection Pump (LDP) (V144).
• Fuel line to engine.
• Leaks at lines and components of tank system can sometimes be located using a nonflammable, environmentally compliant leak detection spray. For this, initiate leak diagnostic several times in sequence to build up pressure in the system. At leaking areas, bubbles will form.
- Perform a visual inspection on the fuel system components and tank ventilation system:
• Fuel tank
• EVAP canister
• Leak detection pump
• EVAP canister purge regulator valve 1
• Due to the form or function of the components, leaking areas may not always be localized by spraying on leak detection spray. It may be necessary to clamp off the relevant component using (3094) and initiate tank leak detection diagnostic. If the leak is no longer indicated, the component that was clamped off is faulty. If clamped off directly at the leak detection pump and a leak is still indicated, the leak detection pump itself is leaking.