Evaporative Emission (EVAP) Canister System, Checking For Proper Seal

Evaporative Emission (EVAP) Canister System, Checking For Proper Seal

NOTE: For vehicles with engine code AEG, the test for "EVAP canister system, proper seal" is only possible as of model year 1999.

Function test
- Select measuring value 'Test-ID 01: Tank leak test" and check whether the specified value is being reached, Diagnostic mode 8: Tank leak test. Diagnostic Mode 8: Tank Leak Test
- Check specified value of tank leak test at idle.

Specified value: Test function active

NOTE:
- During tank leak test, Engine Control Module (ECM) limits "test function active" to 12 minutes.
- If the accelerator pedal is depressed during the test, the test will be aborted.
- To repeat the tank leak test, switch ignition off and start engine again and let run at idle.

- End diagnosis and switch ignition off.

If a leak is detected:

Checking proper seal
If a small or large leak was recognized during the test of the EVAP canister system, proceed as follows.
- Remove right rear wheelhousing liner.
- Disconnect connection hose from leak detection pump at EVAP canister and seal it.
- Repeat function test.

If malfunction persists:
- Check connection lines and hoses between leak detection pump and EVAP canister for proper seal. EVAP canister system components, removing and installing.
- Repeat function test.

If malfunction persists:
- Check whether fuel filler cap is completely closed or whether seal leaks, replace if necessary.
- Check whether union nut of Fuel Pump (FP) unit is tightened or whether sealing ring is leaking; replace if necessary. Fuel Pump (FP) unit, removing and installing.
- Repeat function test.

If malfunction persists:
- Remove EVAP canister and check for cracks and leaks, replace if necessary. EVAP canister system components, removing and installing.
- Check connecting lines and hoses between EVAP canister and fuel flap unit or Evaporative Emission (EVAP) canister purge regulator valve for proper seal.

EVAP canister system overview.
- Check hoses and hose clamps for secure seating.
- Repeat function test.

If malfunction is no longer present:
- Erase DTC memory of Engine Control Module (ECM). Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes