Minor Leak - Permanent Fault

ECM-430D LEAK DIAGNOSTIC SMALL LEAK
MINOR LEAK - PERMANENT FAULT


Safety
First read Service Precautions


Checking hoses and pipes
Check that the fuel tank filler cap is on properly and that its seal is intact.
Check that the hoses and hose connectors at the EVAP canister, EVAP canister shut-off valve and fuel tank are not leaking or pinched.

Remedy as necessary.

Carry out a quick test of the fuel system.


General about fuel tank system test



The engine management system has a built-in function for carrying out a quick check of fuel tank system sealing. By activating the function, the control module is able to determine whether the fuel tank system is fault free or if there is any leakage faster than usual. The condition for the test is that no diagnostic trouble codes (DTCs) are stored, engine temperature is above 70°C (158°F) and that the engine is idling.

For further information about fuel tank system test diagnostics, Leak Diagnostics

- Canister purge (CP) valve
- EVAP canister
- EVAP canister shut-off valve
- Fuel tank pressure sensor
- Air cleaner (ACL)


Checking the engine coolant temperature (ECT)



Note: If the engine coolant temperature (ECT) is under 70°C (158°F) the test cannot start.

- Start the engine.
- Read off engine coolant temperature (ECT)
If the engine coolant temperature (ECT) is under 70°C (158°F) allow the engine to reach operating temperature or interrupt the test.

Is the temperature above 70°C (158°F)?
Yes - Continue below.
No - Abort test.


Start the fuel tank system test

Note: If the engine coolant temperature (ECT) is under 70°C (158°F) the test cannot start.

- Engine idling.
- Start the quick test

Leak diagnostic active
This parameter displays that test is underway. When the parameter displays YES and has returned to NO the test is ready or has been interrupted.

Fault status
These parameters display the status of those diagnostic tests which are included in the leak diagnostic.

The following alternatives are available:
1 When the active leak diagnostic has displayed YES and then NO and all fault status have moved to clear, fault not found, the test has been run without any faults being found.
2 When the active leak diagnostic has displayed YES and then NO and one of the fault status displays fault found. A fault has been detected in that part of the test.
3 When the active leak diagnostic has displayed YES and then NO and one or several of the fault statuses has not gone and no fault is detected. Or if active leak diagnostic unchanged status to YES. The test has not started or been interrupted. Try again or select 3 to interrupt.

Select an alternative
1 - Testing Complete.
2 - Continue below.
3 - Testing Complete.


Test pressurization of the fuel tank system



- Max 50 liters 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 5646 to hose and pressure regulator 999 5544 to manometer.

Set pressure to 7 kPa (1.02 psi) (Read on the manometer 999 5646).

Cock at right angles to the hoses.

WARNING! Max 10 kPa (1.45 psi).

Let the pressure build up for 5 minutes.
Shut off the cock (the pressure may drop 1-2 kPa (0.15-0.29 psi) before stabilizing) and Read 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 - Continue below
No - Skip to "Checking fuel tank system"


Checking the hose to the EVAP canister shut-off valve
Check the hose to the EVAP canister shut-off valve. Check the seal. Check the terminals.

Remedy as necessary.

Was a fault detected?
Yes - Try a new EVAP canister shut-off valve according to EVAP Canister Shut-Off Valve, Replacing
Skip to "Verification"
No - Skip to "Verification"


Checking fuel tank system



- Ignition off.
- Carefully pressurize the fuel tank system to 7 kPa (1.02 psi).
EVAP canister shut-off valve right angles to the hoses.

WARNING! Max 10 kPa (1.45 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 top of the fuel tank.

WARNING! Never leave the car unattended with its system pressurized.


Verification



- Ignition off.
- Reinstall all hoses/components.
- Start the engine.

Activate the quick fuel tank system test.

Does the diagnostic trouble code (DTC) recur?
Yes - Continue below.
No - Testing Complete.


Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed. Exit fault tracing for this diagnostic trouble code (DTC) or make another attempt.