Hello, and welcome to JA!! the code P0440 indicates a large leak in the evap system. this is normally checked with a smoke tool. most coomon failures is the gas cap loose or leaking, and the evap vent sol stuck open. also seen a few cases of the wiring harness to the vent sol either broken or rub thru somewhere. here is some info on this wiring problem.
The EVAP large leak test applies vacuum to the evaporative emission (EVAP) system and monitors vacuum decay. The powertrain control module (PCM) monitors the fuel tank pressure (FTP) sensor signal to determine the vacuum decay rate. At an appropriate time, the PCM turns the EVAP canister purge valve ON (open) and the EVAP vent valve ON (closed). This allows the engine to draw a vacuum on the EVAP system. At a calibrated time, or vacuum level, the PCM turns the purge valve OFF (closed), sealing the system, and monitors the FTP sensor input in order to determine EVAP system vacuum. If the system is unable to achieve the calibrated vacuum level, or the vacuum level decreases too rapidly, DTC P0440 will set.
: Service Engine Soon (SES) Light Illuminated, DTC P0440 Set (Replace Fuel Tank Evaporative Emissions Control System (EVAP) Vent Solenoid Harness) -
|Subject:||Service Engine Soon (SES) Light Illuminated, DTC P0440 Set (Replace Fuel Tank Evaporative Emissions Control System (EVAP) Vent Solenoid Harness)|
|Models:||2000-2002 Chevrolet Cavalier|
|2000-2002 Pontiac Sunfire|
Some customers may comment that the SES light is/was illuminated.
A technician may find DTC P0440 is stored in the PCM.
The EVAP solenoid harness may be misrouted around the rear antilock brake (ABS) wire harness causing a chaff/damage to the EVAP vent solenoid harness, setting DTC P0440.
Follow the service procedure below to diagnose and correct this condition.
- Install a Tech 2 scan tool and select the appropriate vehicle. Verify that a DTC P0440 is stored in the PCM.
- Raise the vehicle on a hoist. Refer to Lifting and Jacking the Vehicle in General Information
- Locate and inspect the EVAP vent solenoid harness (3) routing. The harness may be routed below the ABS wiring harness (4) at the right rear corner of the fuel tank, causing stress on the EVAP solenoid harness (3).
- Disconnect the EVAP vent solenoid harness (3) from the EVAP vent solenoid (2) and connector C313 (1). Discard the EVAP vent solenoid harness (3).
- Connect the new EVAP vent solenoid harness (3), P/N 22687059, to the EVAP vent solenoid (2), route the harness above the rear ABS harness (4) and connect the EVAP vent solenoid harness (3) to connector C313 (1).
- Lower the vehicle.
- Clear the DTC's with the Tech 2 scan tool.
Vent Solenoid Harness