EVAP System, Checking For Leaks
Diagnostic Procedures
EVAP System, Checking for Leaks
Special tools, testers and auxiliary items required
• Smoke tester.
• EVAP and Fuel Supply System Vacuum hose and line routing diagram.
• Secure all hose connections using hose clamps appropriate for the model type.
• Replace seals and gaskets when performing repair work.
Test procedure
- Observe safety precautions. Refer to => [ Safety Precautions ] Safety Precautions
- Observe Clean Working Conditions. Refer to => [ Clean Working Conditions ] Clean Working Conditions
- Perform a preliminary check to verify the customers complaint. Refer to => [ Preliminary Check ] Preliminary Check.
Leak checking
- Using a Smoke tester, check the Evaporative Emission (EVAP) canister system for leaks.
• Always follow the manufacturers directions for the proper installation and operation of the Smoke tester being used.
If a leak is detected:
- Check the fuel filler cap seal for damage and for proper installation. Replace if necessary.
- Check the seals under the locking flanges and the union nuts are properly tightened on the fuel tank.
- Check all hose connections of the fuel supply system and replace or repair any leaking lines.
- Check all hose connections of the EVAP system and replace or repair any leaking lines.
- Repair or replace any damaged component.
If no leaks are found in the EVAP and Fuel Supply System:
- Erase the DTC memory if a DTC was set. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09.
- Perform a road test to verify repair.
If a DTC was set and does not return:
Generate readiness code. Refer to => [ Readiness Code ] Monitors, Trips, Drive Cycles and Readiness Codes.
If a DTC does return and no leaks are found in the EVAP and Fuel Supply System:
- Check for any DTC codes pertaining to the EVAP and Fuel Supply Systems. If a DTC is stored, perform the diagnostic test procedure for the suspected component. Refer to => [ Diagnostic Mode 03 - Read DTC Memory ] Diagnostic Modes 01 - 09.