2. Starting the Quick Test

ECM-4047 CANISTER PURGE (CP) VALVE/CANISTER SHUT OFF VALVE
LEAK DIAGNOSTIC

Starting the quick test



Note! Certain conditions must be met for the diagnostic to start:
- Engine speed < 3500 rpm.
- Engine coolant temperature (ECT) > 30°C.
- Normal battery voltage.
- Quantity of fuel in the tank < 60 liters.
- Height above sea level < 2500 m.

- Start the engine and let it idle.

Start the quick test.

Hint: If the EVAP canister is overfull, the engine may start to run unevenly and possibly even stall. If this happens, restart the engine and the quick test. Let the engine idle until the status changes from inhibited to running. Then increase the engine speed (RPM) to between 1500 - 2000 rpm. Maintain this engine speed (RPM) until the status changes to finished.

Information
In the event of leakage in the fuel tank system, only one diagnostic trouble code (DTC) will be stored (only data from status window DTC1 will be displayed). The 2nd status window remains empty.
If there is a smaller leak that is not large enough for a diagnostic trouble code (DTC) to be stored, 2 diagnostic trouble codes (DTCs) and the test values will be displayed.

Other parameters:
- EVAP canister shut-off valve. Closes when it is active, ON (red line).
- Fuel tank pressure (yellow line).
- Canister purge (CP) valve (green line).

Hint: When the curves go outside the measurement range, press "AUTORANGE" so that they are visible within the measurement range again.

The quick test process
When the quick test is complete, the result is displayed in status window DTC1 and where applicable DTC2.
If a fault was detected during the test, a diagnostic trouble code (DTC) and a test value will be displayed. Fault-tracing must then be carried out by selecting this test.
If no faults were found during the test, diagnostic trouble codes (DTCs) will be displayed in both the status windows instead. The test value must then be compared with the quantity of fuel in the fuel tank to determine whether there is a small leak that the quick test was unable to detect. (See the information above).

The following alternatives are available:
- When the leak diagnostic is complete and the test has ended without any faults being detected.
- When the test has detected a fault in the EVAP canister shut-off valve or in the canister purge (CP) valve.
- When the test has detected a large leak.
- When the test has detected a fault in the canister purge (CP) valve.
- When the test has detected a small leak.

Select an alternative.

1 - Testing Complete.
2 - 3. Checking the Fuel Tank Pressure Sensor
3 - 4. Checking the Vacuum Downstream of the Canister Purge (CP) Valve
4 - 5. Checking the Vacuum Downstream of the (CP) Valve
5 - 6. Test Pressurization of the Fuel Tank System