LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 2003 >> Matrix Base, FWD, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 15 (Engine Control System Self-Diagnostics) >> Diagnostic Tests >> DTC P0440: Evaporative Emission Control System >> Diagnosis & Repair
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnosis & Repair

WARNING: This page is about a different car, the 2002 Toyota Prius. However, it is still accessible from the selected car via links, so may be relevant.
  1. Check for cracks and deformations in fuel tank, charcoal canister and fuel tank filler pipe. Charcoal canister is located near fuel tank. See Fig 1. Fuel tank filler pipe may also be referred to as fuel inlet pipe. Check for loose connections and disconnected hoses and tubes around fuel tank and charcoal canister. If no problems exist, go to next step. If any problem exists, repair as necessary.
  2. Check fuel tank cap to ensure fuel tank cap is a Original Equipment Manufacturer (OEM) fuel tank cap. If fuel tank cap is an OEM fuel tank cap, go to next step. If fuel tank cap is not an OEM fuel tank cap, replace fuel tank cap with an OEM fuel tank cap.
  3. Ensure fuel tank cap is properly installed and tightened. If fuel tank cap is properly installed and tightened, go to next step. If fuel tank cap is not properly installed or tightened, reinstall and tighten as necessary.
  4. Check fuel tank cap for damage and damaged gasket. If fuel tank cap is not damaged and gasket is okay, go to next step. If fuel tank cap or gasket is damaged, replace fuel tank cap with an OEM fuel tank cap.
  5. Visually inspect fuel tank filler pipe for damage. If fuel tank filler pipe is not damaged, go to next step. If fuel tank filler pipe is damaged, replace fuel tank filler pipe.
  6. Check vapor pressure sensor connection at fuel tank. Vapor pressure sensor is located on corner of fuel tank. See Fig 1. Check vacuum hoses to charcoal canister, purge flow switching valve VSV and EVAP VSV for correct installation, loose connections, disconnected hoses and damage. See Fig 1 for component location. If no problems exist, go to next step. If any problem exists, repair or replace components as necessary.
  7. Check hoses and tubes between fuel tank, fuel tank filler pipe, charcoal canister and fresh air valve for correct installation, loose connections, being disconnected and damage. Fresh air valve is located on top of fuel tank, near end of charcoal canister. See Fig 1. If no problems exist, go to next step. If any problem exists, repair or replace components as necessary.
  8. Check charcoal canister for cracks or damage. If charcoal canister is okay, go to next step. If charcoal canister is damaged, replace charcoal canister. See CHARCOAL CANISTER under EMISSION SYSTEMS & SUB-SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
  9. Remove glove box for access to ECM with electrical connectors still installed on ECM. See Figure. Turn ignition on. Using voltmeter, check voltage between terminals No. 2 (Yellow/Red wire) and No. 18 (Brown wire) at ECM electrical connector E8. See Figure. This is the VC and E2 terminals on ECM. Voltage should be 4.5-5.5 volts. If voltage is within specification, go to next step. If voltage is not within specification, replace ECM.
  10. Turn ignition off. Connect voltmeter between terminals No. 18 (Brown wire) at ECM electrical connector E8 and No. 22 (Blue/Red wire) at ECM electrical connector E9. See Figure. This is the E2 and PTNK terminals on ECM. Remove fuel tank cap. Turn ignition on and note voltage. Voltage should be 3.0-3.6 volts. If voltage is not within specification, go to next step. If voltage is within specification, go to step  12.
  11. Check for open and short in wiring harness and electrical connectors between vapor pressure sensor and ECM. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, replace vapor pressure sensor. See VAPOR PRESSURE SENSOR under EMISSION SYSTEMS & SUB-SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. If wiring harness or electrical connector is defective, repair as necessary.
  12. Inspect fuel tank and any valves on fuel tank for cracks and damage. If fuel tank or valves are defective, repair or replace components as necessary. If fuel tank and valves are okay, it is likely that DTC was caused by fuel tank cap not being fully tightened or was improperly installed.
    Fig 1: Locating Emission System Components
    G00027289Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
scientia non olet · About LEMON Manuals