Quick Fuel Tank System Test

General about fuel tank system test







The engine management system has the built-in function of carrying out a quick check of fuel tank system sealing. By activating the function the control module determines if 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 diagnostic.
- Canister purge (CP) valve
- EVAP canister
- EVAP canister shut-off valve
- Fuel tank pressure sensor
- Air cleaner (ACL)

Checking Diagnostic Trouble Codes (DTCs)







NOTE: The test cannot be started if Diagnostic Trouble Codes (DTCs) are stored. Therefore it is important to check whether there are any Diagnostic Trouble Codes (DTCs) stored.


- Ignition on
- Read Diagnostic Trouble Codes (DTCs)

If Diagnostic Trouble Codes (DTCs) are stored the test must be halted and fault-tracing for Diagnostic Trouble Codes (DTCs) must be carried out first.


Checking 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 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.

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

Swifttest Running Status
This parameter shows the status of the test, with two possible values:
- RUNNING
- NOT RUNNING

Fault Status
These parameters show the status of the diagnostic tests that are included in the Leakage Diagnostic Test:
- Status failure Canister Close Valve
- Status failure Rough leak
- Status failure PCV Open
- Status failure Small Leak.

The Fault Status parameters have three possible values, depending on the test outcome:
- Not ready
- Ready, no fault found
- Ready, fault found

Sensor/actuator parameters (plotter)
- Fuel Tank Pressure (red line)
- Canister Close Valve (green line)
- PCV (yellow line)

Swift Test Procedure

Initiate Swift Test
The Swift Test is initiated with "Start reading" button. When the test has started, "RUNNING" will be displayed in the Running status display. The test will go through the individual steps in order:
1. Status failure Canister Close Valve
2. Status failure Rough Leak
3. Status failure PCV Open
4. Status failure Small Leak.

Stop/abort test conditions
The test will stop when one of these conditions has been fulfilled:
- The test has been completed successfully
- A fault condition has been found
- One or more required conditions for performing the test is no longer valid. This could for example be extreme fuel trim integrator value, caused by saturated canister.

When the test has stopped, "NOT RUNNING" will be displayed. To complete the test cycle, and store possible DTCs, the accelerator has to be depressed briefly and then released. The Swift Test Status will then shift from "NOT RUNNING" to "RUNNING" and then back to "NOT RUNNING". This procedure will also re-initiate a test that has been aborted. Three such attempts are possible, after that the engine has to be switched off and restarted to enable a new Swift Test cycle.

Test complete
If a fault has been detected by the test, a DTC will be stored in the Engine Control Module. Proceed with the applicable fault tracing procedure. The DTCs must be cleared before the Swift Test can be started again.