EVAP System, Checking For Proper Seal

Diagnostic Procedures



EVAP System, Checking for Proper Seal

Function Test

- Select measuring value "Test ID 01: Tank leak test" and check whether specified value is attained => [ Diagnostic Mode 08 - Request Control of On-Board System, Test or Component ] Diagnostic Modes 01 - 09, Diagnostic mode 8: Tank leak test.

- Check specified value of tank leak test at idle. Specification: Test function active

• During tank leak test, "test function active" is limited to approx. 12 minutes.

• If the accelerator pedal is depressed during the test, the test will be aborted.

• To repeat the tank leak test, switch the ignition off, start the engine again, and let it run at idle for at least 15 minutes.

- End diagnosis and switch ignition off.

If a leak is detected:

Checking for Leaks

• Observe safety precautions => [ Safety Precautions ] Safety Precautions.

• Observe rules for cleanliness => [ Clean Working Conditions ] Clean Working Conditions.

If a small or large leak was recognized during the test of the EVAP canister system, proceed as follows.

- Disconnect connecting line from diagnostic pump for fuel system at EVAP canister and seal, EVAP canister system components, removing and installing.

• To disengage, compress the buttons at the hose coupling.

- Repeat function test.

If malfunction persists:

- Check connection lines and hoses between diagnostic pump for fuel system and EVAP canister for proper seal => [ EVAP System, Checking for Proper Seal ] , EVAP canister system components, removing and installing.

- Repeat function test.

If malfunction persists:

- Check whether fuel filler cap of fuel filler tube is completely closed or whether seal leaks; replace if necessary.

- Check whether fuel pump locking rings are tightened or if the sealing ring leaks; replace if necessary:

• Fuel delivery unit, Fuel level sensor and suction jet pump (right side), removing and installing.

• Fuel delivery unit, Fuel level sensor and suction jet pump (left side), 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 lines and hoses between EVAP canister and fuel filler tube or Evaporative Emission (EVAP) Canister Purge Regulator Valve 2 (N333), parts of EVAP canister system, removing and installing.

- 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 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09, Diagnostic mode 4: Reset/erase diagnostic data.

- Generate readiness code => [ Readiness Code, Generating ] Monitors, Trips, Drive Cycles and Readiness Codes.