P0446

P0446 00

Canister Close Valve Circuit, Malfunction







Fault symptom
Check Engine

On-board diagnosis

Type of diagnosis:
Continuous. But ceases when fault criteria fulfilled and does not restart until next driving

Enable criteria:
Battery voltage must be between 11 - 16 V.
Engine running.
Intake air temperature is higher than +4 degree C.
Tank pressure lower than -0.8kPa.
Tank purge diagnostics inactive.
NONE of the following DTCs must be detected:
- P0444, P0445
- P0451, P0452, P0453
- P0498, P0499
- P0686, P0687

When these conditions are met, the valve opens. Afterwards, diagnostics checks if the tank pressure has risen to the desired level within a calibrated time period.

Fault criteria:
The tank pressure has not increased 0.4 kPa within 8 seconds after the valve has opened.

Depenent
None

System reaction to a fault:
Fuel adaption is blocked and reset.
Purge blocked.

OK report:
Tank pressure has increased more than 0.4 kPa within 8 seconds after the valve has opened.

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

Diagnosis regards:
Blockage of fresh air intake via shut-off valve to evaporative emission canister or from the evaporative emission canister to the tank.

Functions in the diagnostic tool related to the fault:
Activation:
- Canister Close Valve