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P1441

Read the instructions below then start the fault diagnostic procedure.

Symptom: CHECK ENGINE. Possible faulty readings on the fuel gauge in the MIU.

P1441

EVAP Purge valve. Malfunction and malfunctional fuel level sensor.



Fault symptoms


• CHECK ENGINE.

• Possible faulty readings on the fuel gauge in the MIU.


On-Board Diagnostics

Type of diagnosis:


- Once per driving cycle. Interrupted when fault criteria fulfilled or OK reported. Restarts next driving cycle.


Test 1

Enable criteria:


- Coolant temperature when starting between 5-40°C. Purging is not active. Idling speed. Max. one change of status of the brake light switch. Volume of fuel in tank between 9-54 litres. The vehicle at a standstill for 5 sec.

When the above conditions are fulfilled for more than 5 sec. the diagnosis will start. Should the diagnosis be interrupted the speed must exceed 0 on one occasion before the diagnosis is allowed to be restarted. The diagnosis continues then as follows: The shut-off valve is activated at the same time as the purging is interrupted for 3 sec. During this time the tank pressure is being observed.


Test 2

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 for more than 5 sec. 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.


Fault criteria

Test 1


- If the pressure drops more than 40 Pa/s then an internal leakage in the canister purge valve has been detected.


Fault criteria

Test 2:


- If the pressure drops more than 27.5 Pa/s then an internal leakage in the canister purge valve has been detected. If the pressure increases by more than 3 Pa/s then there is major fuel evaporation, Test 2 will then be repeated. If it then continues to rise by more than 3 Pa/s the diagnosis ceases. To enable the diagnosis to be restarted the vehicle must be put in motion. When the pressure increases less than 3 Pa/s the diagnosis is complete.


Generating diagnostic trouble codes


- Fuel Level, plausibility diagnosis: Because the fuel level is used as enable criteria in certain diagnoses, the control module must know that the fuel level value is plausible. The way it works is that the Trionic receives a bus message ”Fuel level XX litres" from the MIU. During driving the Trionic observes the value and as the car is driven, fuel is consumed. The Trionic makes sure the fuel level value drops. In the Trionic a number of important filtrations are carried out to avoid faults caused by, for instance, splashing fuel in the tank, starting uphill. The fuel level diagnosis can be called a support diagnosis as it does not generate a DTC, but if for instance the EVAP Purge valve diagnosis has reported a leakage in the EVAP canister purge valve then DTC P0441 is normally generated. If on the other hand the tank integrity diagnosis has reported the same fault and the fuel level diagnosis has simultaneously reported a fault then DTC P1441 is generated instead.

DTC P0441 and P1441 are generated when fault criteria have been fulfilled during Test 1 or Test 2 and the dependents are OK.


Dependents:


- P0444, P0445, P0501, P0502, P0506, P0507, P1444, P1445, P1576 and P1577.


System reaction to a fault:


- None.


OK report:


- Test 1 or Test 2 performed once and fault criteria not fulfilled.


Fault handling: Fault handling III, other emission-related components and functions

Diagnostic help

Fault diagnosis concerns a valve fault.

Functions in the diagnostic tool related to the fault:


• Diagnostic status for the diagnosis.

• Activate EVAP diagnosis.

for more information, see Menu "Activate"


Note

During the final check of a rectified fault, the diagnostic tool activation command must be used so that Test 1 is initiated irrespective of starting temperature.