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P1441

Read the instructions below then start the fault diagnostic procedure.

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

P1441


EVAP Purge Valve Circuit. Function faulty at the same time as the fuel level sensor diagnosis has reported a fault.



Fault symptoms


• CHECK ENGINE.

• Possible faulty reading on the fuel gauge in 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 at start between 5-40°C. Purging not active. Idling. Max. one change in status of brake light switch. Fuel volume in tank between 11-54 litres. Car stationary for 5 sec.

The diagnosis will start once the above conditions have been fulfilled for more than 5 seconds. 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 at the same time as the purging is stopped for 3 sec. In the meantime the tank pressure is observed.


Test 2

Enable criteria:


- Coolant temperature at start between 5-40°C. Difference between coolant temperature and intake air temperature less than 5°C. If the above conditions are not fulfilled a Special test (warm start) will be carried out instead. (Test 3). Idling. Max. one change in status of brake light switch. Fuel volume in tank between 11-54 litres. Purging adaptation higher than -15%. Intake air pressure at least 20 kPa lower than the atmospheric pressure. The vehicle stationary for 5 sec. Battery voltage between 10-16 Volts. Tank pressure between -300 to 100 Pa.

The diagnosis will start once the above conditions have been fulfilled for more than 5 seconds. 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 possible purging is stopped for 4.5 sec. Tank pressure is observed, falling pressure reveals leaks in purging valve. Rising pressure of more than 3 Pa/s points to fuel evaporation, in these cases the diagnosis is repeated. If it becomes apparent that the pressure is rising by more than 3 Pa/s the diagnosis is interrupted. For pressure increases less than 3 Pa/s then Test 2 is complete.


Fault criteria

Test 1:


- If the pressure falls by more than 40 Pa/s then an internal leak in the purging valve has been detected.


Fault criteria

Test 2:


- If the pressure falls by more than 27.5 Pa/s then an internal leak in the purging valve has been detected. If the pressure has risen by more than 3 Pa/s then there is major fuel evaporation, Test 2 will then be repeated. If pressure increase continues by more than 3 Pa/s then the diagnosis is interrupted. The vehicle must be put in motion before the diagnosis is can be restarted. At pressure increases less than 3 Pa/s then the diagnosis is complete.


Generation of diagnostic trouble codes


- Fuel level, plausibility diagnosis: Because fuel level is used as an enable criterion in certain diagnoses, then the control module must know that fuel level value is plausible. It works in such a way that Trionic receives the bus message ”Fuel level XX litres" from MIU. While driving Trionic observes the value and as the vehicle is driven it is consuming petrol, Trionic sees that the fuel level value will fall. In Trionic there is a number of filtrations of the value so as to avoid inaccuracies due to, for example, splashing fuel in the tank and starting on inclines. The fuel level diagnosis can be said to be a support diagnosis, it does not generate its own diagnostic trouble codes, but if, for example, the EVAP valve diagnosis has reported a leakage in the purging valve then DTC P0441 is normally generated. If on the other hand the integrity diagnosis has reported the same fault and the fuel level diagnosis at the same time has also reported a fault then DTC P1441 is generated instead.

Diagnostic trouble codes P0441 and P1441 are generated when the fault criteria are fulfilled during Test 1 or Test 2 and the dependants 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: (For more information, see “Fault diagnosis, general".)


- Type III.


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 “Fault diagnosis, general".

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.