p0449
Moderate
Cadillac · Sedans
Evaporative Emission Control System Vent Control Circuit
Quick Answer
Error code P0449 on your Cadillac Sedans means: Evaporative Emission Control System Vent Control Circuit. This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
How to Fix It
1
Inspect vacuum lines to vent control valve
2
Test purge control valve operation
3
Check solenoid wiring and connections
4
Verify carbon canister for blockage
5
Replace vent valve if stuck or faulty
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
Vent solenoid valve
Vacuum hose
Clamps
Purge control valve
Related Error Codes