DTC P0440 Or P1440: EVAP Control System: Procedure

Ensure fuel cap is original equipment. Attempt to turn fuel cap clockwise. If fuel cap was tightened properly, go to next step. If fuel cap was not tightened properly, clean fuel cap and filler neck with compressed air. Reinstall cap and retest system.
While removing fuel cap, listen for air escaping from fuel tank. If air escaped from fuel tank, go to step 4. If air did not escape from fuel tank, go to next step.
Using a suitable hand vacuum/pressure pump with fuel cap adapter, apply pressure and vacuum to fuel cap. Fuel cap vacuum relief valve should open when pressure reaches 2.22-2.90 psi (15.3-20.0 kPa) and when vacuum reaches 98-1.78 in. Hg. If operation is as specified, go to next step. If operation is not as specified, replace fuel cap and retest system.
Check EVAP system for leaks. See EVAP CONTROL SYSTEM under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING article. Repair, if necessary. If no leaks are found, remove water separator. See Fig 1. Visually inspect water separator for blockage or cracks. Inspect hoses for cracks. Repair as necessary and retest system. If no problems are found, go to next step.

CAUTION: DO NOT disassemble water separator.

With water separator port "A" plugged, blow air into port "B". See Fig 2. Air should flow out of port "C". With port "C" plugged, blow air into port "B". Air should flow out of port "A". If operation is as specified, go to next step. If operation is not as specified, replace water separator and retest system.
Check EVAP-CVCV and circuit. See DTC P0446: EVAP CANISTER VENT CONTROL VALVE . Repair as necessary and retest system. If no problems are found, remove EVAP canister with EVAP-CVCV attached. Invert EVAP canister and attempt to drain water from EVAP canister. If water drains from EVAP canister, go to next step. If water does not drain from EVAP canister, go to step 8.
Weigh EVAP canister with EVAP-CVCV attached. If EVAP canister weighs less than 4.0 lbs. (1.8 kg), go to next step. If EVAP canister weighs 4.0 lbs. (1.8 kg) or more, inspect EVAP canister for damage and hoses to water separator for poor connections or blockage. Repair as necessary and retest system.
Start engine and warm to normal operating temperature. Turn ignition off. Disconnect EVAP Canister Purge Volume Control Valve (EVAP-CPVCV) hose from EVAP service port. See VACUUM DIAGRAMS article. Start engine and let it idle for at least 80 seconds. While quickly increasing engine speed to 2000 RPM, check for vacuum at EVAP-CPVCV hose. Vacuum should exist. If vacuum does not exist, go to next step. If vacuum exists, go to step 10.
Check vacuum hose for blockage or leak. Repair as necessary and retest system. If hose is okay, remove EVAP-CPVCV. Using jumper wires, apply battery voltage and ground to EVAP-CPVCV terminals. See Fig 3. Check for airflow between ports "A" and "B". Air should flow. Remove jumper wires. Air should not flow. If operation is as specified, go to next step. If operation is not as specified, replace EVAP-CPVCV and retest system.

CAUTION: DO NOT apply more than 27.56 in. Hg of vacuum to AP sensor.

Remove Absolute Pressure (AP) sensor from its bracket and disconnect vacuum hose. See Figure. Turn ignition on. Measure voltage between ground and ECM terminal No. 80 by backprobing. See Figure and Figure . Voltage should be 3.2-4.8 volts. Using a hand vacuum pump connected to AP sensor, apply 7.87 in. Hg of vacuum to AP sensor. Voltage should be 1.0-1.4 volts less than voltage measured with no vacuum applied. If voltage is as specified, go to next step. If voltage is not as specified, replace AP sensor and retest system.
Remove access cover from under rear seat. Remove fuel level sensor from fuel tank. Measure resistance between fuel level sensor and fuel pump connector terminals No. 4 and 5, with sensor at specified temperatures. See Figure. See FUEL TANK TEMPERATURE SENSOR RESISTANCE table. If resistance is as specified, go to next step. If resistance is not as specified, replace fuel level sensor and retest system.

CAUTION: DO NOT apply more than 5.91 in. Hg of vacuum to EVAP-CSPS. Replace EVAP-CSPS if it has been dropped from a height of more than 20" (.5 m) onto a hard surface such as concrete.

Remove EVAP Control System Pressure Sensor (EVAP-CSPS) with its harness connector connected. Turn ignition on. Using a suitable hand vacuum pump, apply 2.76 in. Hg of vacuum to EVAP-CSPS. Measure voltage between ground and ECM terminal No. 84 by backprobing. See Figure and Figure . Voltage should be .4-.6 volt. Disconnect vacuum pump. Voltage should be 3.0-3.6 volts. If voltage is as specified, go to next step. If voltage is not as specified, replace EVAP-CSPS and retest system.
Inspect EVAP system hoses for correct routing. See Fig 4. Repair as necessary and retest system. If hoses are okay, clean purge line with compressed air and go to next step.
Measure resistance between fuel level sensor and fuel pump harness connector terminals No. 2 and 5, with sensor at specified positions. See Figure. See FUEL LEVEL SENSOR RESISTANCE table. If resistance is as specified, go to next step. If resistance is not as specified, replace fuel level sensor and retest system.
No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.