P1442

P1442 00

EVAP System, Fuel Level Sesor Failure and Small Leak Detected







Fault symptom
Check Engine

On-board diagnosis

Type of diagnosis:
Once per driving cycle. Stopped when fault criteria are fulfilled or OK reported.

Enable criteria:
Phase 1:
- The diagnosis is performed by closing the shut-off valve and opening the EVAP canister purge valve while the tank pressure is being registered. The pressure should then drop.

Phase 2:
- Bleeder valve closed; pressure increase in Pa/s calculated. Pressure must not rise too much.

Diagnostics can be carried out under 4 different operating conditions:
- After cold start while stationary.
- After cold start while driving.
- After warm start while stationary.
- After warm start while driving.

NONE of the following DTCs must be detected:
- P0117, P0118
- P0444, P0445
- P0451, P0452, P0453
- P0498, P0499
- P0501
- P0685, P0686, P0687

Diagnostics uses different calibration data for various operating conditions. Starting from cold implies an intake and radiator temperature below 40 degree C during start. Criteria for starting from cold are valid during 15 minutes after start. Several conditions can interrupt diagnostics. After starting from cold, diagnostics restarts immediately if the vehicle speed exceeds 0 km/h. After warm start, a speed of over 44 km/h is required for a specific period of time before diagnostics restarts. Normally, the diagnosis takes 5 minutes with the engine idling if the intake temperature is above +15 degree C.

Fault criteria:
Pressure increase during phase 2 has been calculated and compared with fuel level in the tank. The pressure increase indicates a small leak; a hole with a diameter of 1.0 - 2.5 mm. At the same time, a fuel level sensor fault has been detected, making the EVAP diagnosis unreliable.

Dependent
None

System reaction to a fault:
None

OK report:
Diagnostics carried out without fault reported.

Fault handling:
Type III
(See Description of On-Board Diagnostics/Fault handling III, "Other emission-related components and functions" for more information.)

Checking the wiring harness
Move the wiring harness at several spots and in several directions to reveal intermittent breaks and short-circuits. Check switches, connectors and crimp connections for oxidation, retracted pins and pin clamping force.

Diagnostic help
In case of a fault in the sensor, the diagnosis will take 40 litres as a substitute value. When the EVAP diagnosis result has normalized above the fuel level, a fault may result even though there is no leak. Diagnose the fuel level sensor first and then check the EVAP system.