The gas cap is not installed or working properly; The purge solenoid has failed; The canister is plugged and not working properly

Read the code and live data with an OBD-II scanner; Look for exhaust or vacuum leaks and check the wiring of the sensor or valve; Test the part before replacing it; Fix the cause, clear the code and test-drive

P0440 on Toyota Corolla E170: Evaporative Emission Control System Malfunction

Short answer: P0440 means “Evaporative Emission Control System Malfunction”. The car’s computer has found a fault in the Emissions system and turns on the Check engine light (MIL). First check: read the code and live data with an OBD-II scanner.

Standard OBD-II code Same meaning on all cars (SAE J2012). Not checked against this car’s factory manual.

Code: P0440
System: Emissions
Dashboard light: Check engine light (MIL)
Applies to: Generic OBD-II meaning. Not every code is used by this car.
Confidence: medium (generic OBD-II definition, not checked against the factory manual for this car)
Source: obd-codes.com

Symptoms and when it is set

Check engine light on
You likely won't notice any drivability problems

Likely causes

The gas cap is not installed or working properly
The purge solenoid has failed
The canister is plugged and not working properly

What to check, in order

Read the code and live data with an OBD-II scanner
Look for exhaust or vacuum leaks and check the wiring of the sensor or valve
Test the part before replacing it
Fix the cause, clear the code and test-drive

Related on this car

Same code on other cars

← P0420 P0441 →

Clearing the code does not fix the fault. If it comes back, the problem is still there. For brakes, airbags and steering, see a trained mechanic.