Small Leak. Permanent Fault
Special tools: 999 5646Checking cables and terminals
Check that the fuel tank filler cap is on properly and that its seal is intact.
Check hoses and hose connectors at the EVAP canister, EVAP canister shut-off valve and fuel tank.
Were any faults detected?
Yes:
^ Proceed to Verification section below.
No:
^ Proceed to next step below.
Checking fuel tank pressure sensor
- Start the engine and idle it.
When the canister purge (CP) valve opens the pressure in the fuel tank should drop.
Does the fuel tank pressure drop?
Yes:
^ Proceed to next step below.
No:
^ Proceed to Checking fuel tank pressure sensor hose section below.
Test pressurization of the fuel tank system
- Max 30 liters (7.92 US.gal.) of fuel in the fuel tank.
- Ignition off.
- Clamp hose between EVAP canister shut-off valve and EVAP canister with a hose clip to seal it off.
- Carefully disconnect the EVAP canister hose from the canister purge (CP) valve.
Connect manometer 999 5648 to hose and pressure regulator 999 5544 to manometer.
Set pressure to 7 kPa (1 psi) (manometer on 999 5648). Cock at right angles to the hoses.
Warning! Max 10 kPa (1.4 psi).
Let the pressure build up for 5 minutes. Close the cock (pressure may drop to 1-2 kPa (0.14-0.18 psi) before stabilizing) and read off pressure. EVAP canister hose cock.
Wait for 10 minutes.
Warning! Never leave the car unattended with its system pressurized.
The pressure should be stable (it may rise a little due to fuel evaporation).
Is the pressure stable?
Yes:
^ Proceed to next step below.
No:
^ Proceed to Checking fuel tank system section below.
Checking hose to EVAP canister shut-off valve
Check hose to EVAP canister shut-off valve for airtightness and check connectors.
Is the hose OK?
Yes:
^ Proceed to next step below.
No:
^ Proceed to Replacing or repairing component section below.
Replacing component
Try a new EVAP canister shut-off valve.
See: Emission Control Systems / Evaporative Emissions System / Leak Detection Valve.
Then continue with:
^ Verification section below.
Replacing or repairing component
Remedy or replace hose.
Then continue with:
^ Verification section below.
Checking fuel tank pressure sensor hose
- Ignition off.
- Remove fuel tank pressure sensor See: Fuel Tank Pressure Sensor.
- Remove hose with Y-nipple.
Check that the nipple and hoses are not blocked.
Are the nipple and hoses blocked?
Yes:
^ Proceed to next step below.
No:
^ Proceed to Replacing component section below.
Replacing or repairing component
Remedy or replace hose or nipple.
Then continue with:
^ Verification section below.
Replacing component
Try a new fuel tank pressure sensor.
See: Fuel Tank Pressure Sensor.
Then continue with:
^ Verification section below.
Checking fuel tank system
- Ignition off.
- Carefully pressurize fuel tank system to 7 kPa (1 psi). EVAP canister shut-off valve at right angles to hoses.
Warning: Max 10 kPa (1.4 psi)
Check fuel tank system by spraying it with soapy water from the EVAP canister to the canister purge (CP) valve and on the line with the pressure regulator and roll-over valve to the fuel tank. Check filler pipe and fuel tank filler cap.
It may be necessary to lower the fuel tank in order to fault-trace hoses and connectors on the top of the fuel tank.
Warning! Never leave the car unattended with its system pressurized.
Then continue with:
^ Verification section below.
Verification
Hint: After carrying out the repair, check that the fault has been remedied as follows:
- Ignition off.
- Reinstall all hoses/components.
- Erase diagnostic trouble codes (DTCs).
- Run the engine to operating temperature (above 70°C (158°F)).
- Air conditioning (A/C) off.
- Gear selector in P or N.
- Engine idling.
- Go into diagnostic test menu. Select leakage diagnostic.
- Wait until the diagnostic is complete. This can take up to 2 minutes.
Read off diagnostic trouble codes (DTCs).
Note: If the texts START CONDITIONS NOT MET or DIAGNOSTIC INTERRUPTED are displayed the diagnostic cannot be carried out. This can have several causes: for example high fuel evaporation, high canister charge, high tank pressure, fuel trim not active or a diagnostic trouble code (DTC) stored after the diagnostic has been activated. Check that no diagnostic trouble codes (DTCs) are stored, restart the car and try to activate the diagnostic again. Sometimes several attempts will have to be made before the diagnostic is carried out.
Does the diagnostic trouble code (DTC) recur?
Yes:
^ Fault not found
No:
^ Fault corrected