T8 / P0446 00
Read the instructions below then
start the fault diagnostic procedure.
Symptom: Fault indicator lamp (for further information see WIS Fault diagnosis, general)
Canister Close Valve Circuit, Malfunction
Fault symptom
Fault indicator lamp (for further information see WIS Fault diagnosis, general)
On-board diagnosis
Type of diagnosis:
| Continuous. But ceases when fault criteria fulfilled and does not restart until next driving cycle. |
Enable criteria:
| Battery voltage must be between 11 - 16 V. |
| Intake air temperature is higher than +4°C. |
| Tank pressure lower than -0.8kPa. |
| Tank purge diagnostics inactive. |
| NONE of the following DTCs must be detected: |
| 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. |
Dependent:
System reaction to a fault:
| Fuel adaption is blocked and reset. |
OK report:
| Tank pressure has increased more than 0.4 kPa within 8 seconds after the valve has opened. |
Fault handling:
| (See section 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:
| (See also description of readings/activations in diagnostic tool) |
