Enable criteria

• Coolant Temperature when starting between 5-40°C. The difference between the coolant temperature and intake air temperature is less than 5 °C. If the above conditions are not fulfilled a special test (warm start) will be carried out instead. (Test 3). Idling speed. Max. one change of status of the brake light switch. The volume of fuel in tank between 9 -54 litres. Purging adaptation greater than -15%. Intake air pressure at least 20 kPa lower than the atmospheric pressure. The vehicle at a standstill for 5 sec. Battery voltage between 10-16 Volts. Tank pressure between -300 and 100 Pa.

The diagnosis will start once the above conditions have been fulfilled. If the diagnosis is interrupted then the speed must exceed 0 on one occasion before it is allowed to restart. The diagnosis continues then as follows: The shut-off valve is activated (closed) at the same time as any purging is interrupted for 4.5 sec. The tank pressure is observed, decreasing pressure reveals a leaking canister purge valve. Increasing pressure by more than 3 Pa/s indicates fuel evaporation, in these cases the diagnosis is repeated. If the pressure continues to rise by more than 3 Pa/s the diagnosis ceases. When the pressure increases less then 3 Pa/s Test 2 is complete.