Aston Martin diagnostic trouble code
P0446: Evaporative Emission System Canister Vent Valve Circuit
Use this reference to understand the recorded condition, confirm the available V8 Vantage or DB9 manual coverage, and follow the documented diagnostic checks before replacing parts.
- Code family
- Powertrain
- Vehicle system
- Emissions and EVAP
- Manual coverage
- DB9
- Warning-lamp status
- DB9: MIL
What Aston Martin code P0446 means
Evaporative Emission System Canister Vent Valve Circuit
DB9 preliminary diagnostic manual · section 2-94
Manufacturer fault-analysis procedure
Manual fault definition
P0446 - Canister Vent Valve circuit
Cautions and notes
NOTE: The integrity of the vapour recovery system is
checked by closing the canister vent valve, opening the
vapour management valves and applying a vacuum
from the inlet manifold. When the fuel tank vacuum is
at an appropriate level, the VMVs are closed.
The vacuum in the closed vapour recovery system may
then be monitored using the fuel tank pressure transducer.
The system checks for small leaks (P0442) or for gross
leaks (P0455).
CAUTION: This code is generated only in the Primary Powertrain Control Module (PCM). Check
that you are working on the primary half of the
engine.
checked by closing the canister vent valve, opening the
vapour management valves and applying a vacuum
from the inlet manifold. When the fuel tank vacuum is
at an appropriate level, the VMVs are closed.
The vacuum in the closed vapour recovery system may
then be monitored using the fuel tank pressure transducer.
The system checks for small leaks (P0442) or for gross
leaks (P0455).
CAUTION: This code is generated only in the Primary Powertrain Control Module (PCM). Check
that you are working on the primary half of the
engine.
Test sequence and decision path
1. Connect the WDS and read the logged DTCs.
2. Use the WDS component control function to trigger the canister vent valve on/off (listen for a
‘click’ as the valves actuate).
If the valve can be heard actuating, the problem
is not present at this time. Check for possible
intermittent circuit faults. If no fault is found, consult Aston Martin Technical Support.
If the valve does not actuate, service the valve or
circuit as necessary. Clear the P0446 code and
run a KOER test to ensure that the problem is
resolved.
Open the corresponding manual page for wiring diagrams and figures
2. Use the WDS component control function to trigger the canister vent valve on/off (listen for a
‘click’ as the valves actuate).
If the valve can be heard actuating, the problem
is not present at this time. Check for possible
intermittent circuit faults. If no fault is found, consult Aston Martin Technical Support.
If the valve does not actuate, service the valve or
circuit as necessary. Clear the P0446 code and
run a KOER test to ensure that the problem is
resolved.