Fuel System, Checking For Leaks: Notes
Special tools and workshop equipment required
- Evaporative Emissions Tester KLI9210
- Evaporative Emissions Tester - Adapter 55KLI9210/55-1
- Hose Clamps - Up To 25 mm 3094
The coupling must audibly engage when locking.
Note the color coding when installing the coupling, refer to Coupling Allocation !
Pull on the coupling to make sure it is secure.
Disconnecting the coupling, refer to COUPLING, DISCONNECTING .
The couplings for the fuel, vacuum and ventilation lines are color coded. There is either a colored dot on the connection or the release button is the corresponding color.
| Connector | Color marking on the connector |
|---|---|
| Fuel supply | Black |
| Fuel Return Line | Blue |
| Ventilation | White beige |
| Vacuum | Green |
Test Conditions
- The Leak Detection Pump -V144- detected a leak.
- Perform "Guided Fault Finding" using the Vehicle Diagnostic Tester.
Evaporative Emissions Tester KLI9210 Preparation:
Depending on the version, the appearance of the Evaporative Emissions Tester KLI9210 may vary.
-- Check the Evaporative Emissions Tester KLI9210 to make sure there is enough fluid in the smoke generator.
-- Set the valve -D- to "Hold".
-- Open the nitrogen bottle -H-.
-- Connect the measuring hose -G- to the self-test connection -B-.
-- Set the valve -D- to "Test".
-- Use the pressure reducer -J- to adjust the pressure to 10 in. H2O (25 mbar).
-- Set the valve -D- to "Hold".
-- The pressure must now be maintained a minimum of two minutes. If the pressure does not hold, check the tester.
Fuel System, Checking For Leaks:
-- Connect the Evaporative Emissions Tester - Adapter 55KLI9210/55-1 to the vent line -A- (color identification: white).
-- Connect the measuring hose -G- from the Evaporative Emissions Tester KLI9210 to the Evaporative Emissions Tester - Adapter 55KLI9210/55-1.
-- Set the valve -D- to "Hold".
-- Connect the Vehicle Diagnostic Tester -1- to the vehicle.
-- Start the engine and let it run in idle.
-- Select the type of operation for Guided Functions on the Vehicle Diagnostic Tester.
-- Select the "Check tank ventilation system for leaks".
-- Activate the test.
-- Watch the pressure gauge on the Evaporative Emissions Tester KLI9210 while the test is running.
- The leak detection pump must pump the fuel system up to a minimum of 7 in. H2O (18 mbar).
If the minimum pressure is not reached, but the pressure reached does not decrease:
-- Turn off the ignition and perform a pressure retention test, refer to Pressure Retention Test . If there is no decrease in pressure: Check the vacuum supply for the leak detection pump, refer to LEAK DETECTION PUMP VACUUM SUPPLY, CHECKING .
The minimum pressure is not reached and the pressure reached decreases immediately:
-- Clamp off the hose to the EVAP canister purge regulator valve 1 using a Hose Clamps - Up To 25 mm 3094 -arrow-.
-- Repeat the test. If the minimum pressure is not reached: Replace the EVAP canister purge regulator valve 1.
If the minimum pressure is not reached again and the pressure reached decreases immediately:
-- There is a leak in the fuel system: Perform the "Fuel System Leak Test", refer to FUEL SYSTEM LEAK TEST .
If the minimum pressure is reached, turn off the ignition.
The valve in the leak detection pump is now closed and the pressure is maintained.
-- Observe the pressure gauge:
If the pressure does not decrease, perform a pressure retention test to locate any possible pinhole leaks, refer to Pressure Retention Test .
If the pressure drops, clamp off the hose to the EVAP canister purge regulator valve 1 using a Hose Clamps - Up To 25 mm 3094 -arrow-.
-- If the pressure stops dropping, replace the EVAP canister purge regulator valve 1.
If the pressure continues to drop, perform the "fuel system leak test", refer to FUEL SYSTEM LEAK TEST .