Diagnostic Procedures
- If QUICK TEST was not performed, go to QUICK TEST under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed, go to next step.
- Check For Visual Causes Of Excessive Fuel Tank Vacuum
Check for kinks or bends in fuel vapor hoses and tubes. Visually inspect EVAP canister inlet port, canister vent solenoid, EVAP dust separator or outlet hose for contamination or foreign material. If a concern is not evident, go to next step. If a concern is evident, remove any contamination or foreign material around fuel vapor hoses and tubes. Repair as necessary. After repair, go to step 7.
- Perform EVAP Leak Test
Connect EVAP Leak Tester to fuel filler pipe. Using scan tool, select DIAGNOSTIC DATA LINK. Select PCM. Select ACTIVE COMMAND MODES. Close EVAP Canister Vent (CV) solenoid by accessing OUTPUT TEST MODE. Pressurize EVAP system to 14 in. H2
O (3.48 kPa). If pressure reaches 14 in. H2
O (3.48 kPa), go to next step. If pressure does not reach 14 in. H2
O (3.48 kPa), check if EVAP vapor management valve is stuck open. Replace if necessary. After repair, go to step 7
- Check For Canister Vent Solenoid Stuck Closed
Press STOP (#4 button) to open CV solenoid. If pressure drops immediately, go to next step. If pressure does not drop immediately, go to HISSING SOUND WHEN REMOVING FUEL CAP
under SYSTEM TESTS (EVAPORATIVE EMISSION) in SYSTEM & COMPONENT TESTING - B2300, B3000, B4000 & TRIBUTE article.
- Check For Fuel Tank Pressure Sensor PID Without Pressure Applied
Disconnect EVAP canister outlet tube at EVAP canister. Turn ignition on, engine off. Using scan tool, select DIAGNOSTIC DATA LINK. Select PCM. Select ACTIVE COMMAND MODES. Access FTP V PID and record reading. If FTP V PID voltage reading is 2.40-2.80 volts, go to next step. If FTP V PID voltage reading is not as specified, replace Fuel Tank Pressure (FTP) sensor. After repair, go to next step.
- EVAP System Leak Test
Connect all disconnected connectors and hoses. Perform EVAP system leak test. Refer to SYSTEM TESTS (EVAPORATIVE EMISSION)
in SYSTEM & COMPONENT TESTING - B2300, B3000, B4000 & TRIBUTE article. If test result is okay, go to step 8. If test result is not okay, locate leak and repair. Repeat this step.
- Drive Cycle
Reconnect all disconnected connectors. Clear DTCs from PCM memory using scan tool. Perform EVAPORATIVE EMISSION REPAIR VERIFICATION DRIVE CYCLE under MONITOR REPAIR VERIFICATION DRIVE CYCLES. Retrieve pending code. If same DTC present, replace PCM. After repair, go to next step. If same DTC is not present, go to next step.
- Verify Trouble Shooting Of DTCs Completed
Perform QUICK TEST under SELF-DIAGNOSTIC SYSTEM. If any DTC is present, go to applicable procedure for other DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no DTCs are set, trouble shooting is complete.