STRAIGHTTALK
TYF Newbie
- Joined
- Mar 5, 2017
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The vehicle has been a daily driver since purchase in 2007 with 36K miles. No issues until now. The Tahoe LT is equipped with a 5.3 engine, 2WD, 154,000 miles and not driven on dirt/gravel roads period.
The issues all started after a recent fill up at a local station topping off the tank, of course those extra few clicks to round the dollar amount off. Within the next few days the vehicle DIC displayed a TIGHTEN FUEL CAP. This began my checking process. The fuel cap was tight and not loose. I stopped into the local dealer and purchased a replacement cap by using the VIN. I installed the new cap. I drove the vehicle about a week and once again the TIGHTEN FUEL CAP came back on in the DIC.
After reading other threads, I had determined that a vent valve solenoid (VVS) may be the issue.Traveled to the parts house and picked up the direct replacement to install. During the removal process of the old unit, i found loose charcoal beads in the hoses connecting the (VVS) to the EVAP Canister. Seeing this issue, it lead me to further investigate.
With seeing the contamination of the charcoal in the system, I began disconnect the other items in the system. EVAP Canister & Hoses, Purge Valve under the hood. Sure enough, after the removal of the components. I found a failed EVAP Canister due to overfilling at the pump.
After all components were removed, I began the process of blowing out the disconnected lines with air until all was clear of contamination.
Before beginning installing, I checked for voltage at both Purge Valve and Vent Valve wiring connectors with KEY in the ON position. All seemed good. With the Key in OFF position no voltage. With the key in the OFF position, I added a little electrical grease to the terminals to accept new parts when plugged in.
Installed all NEW items (EVAP CANISTER, VENT VALVE, and PURGE VALVE) back into the vehicle, cleared codes and test drove. I have refilled the tank twice and I am still getting the TIGHTEN FUEL CAP in the DIC with no CEL only a pending P0455. So I began the process of further investigation with making a smoke bucket and using about 3psi to smoke the system. I am only getting smoke out of the new VENT VALVE but of course I didn't rig up 12volts to command the VVS to close. I would still think other leaks could be viewed in the system though.
I found the GM general Drive Cycle on line. I have completed about 5 of these starting off first thing in the morning. I still receive a TIGHTEN FUEL CAP in DIC without CEL and only a Pending P0455 on the code reader.
Any other pointers would greatly be appreciated.....
Thanks,
The issues all started after a recent fill up at a local station topping off the tank, of course those extra few clicks to round the dollar amount off. Within the next few days the vehicle DIC displayed a TIGHTEN FUEL CAP. This began my checking process. The fuel cap was tight and not loose. I stopped into the local dealer and purchased a replacement cap by using the VIN. I installed the new cap. I drove the vehicle about a week and once again the TIGHTEN FUEL CAP came back on in the DIC.
After reading other threads, I had determined that a vent valve solenoid (VVS) may be the issue.Traveled to the parts house and picked up the direct replacement to install. During the removal process of the old unit, i found loose charcoal beads in the hoses connecting the (VVS) to the EVAP Canister. Seeing this issue, it lead me to further investigate.
With seeing the contamination of the charcoal in the system, I began disconnect the other items in the system. EVAP Canister & Hoses, Purge Valve under the hood. Sure enough, after the removal of the components. I found a failed EVAP Canister due to overfilling at the pump.
After all components were removed, I began the process of blowing out the disconnected lines with air until all was clear of contamination.
Before beginning installing, I checked for voltage at both Purge Valve and Vent Valve wiring connectors with KEY in the ON position. All seemed good. With the Key in OFF position no voltage. With the key in the OFF position, I added a little electrical grease to the terminals to accept new parts when plugged in.
Installed all NEW items (EVAP CANISTER, VENT VALVE, and PURGE VALVE) back into the vehicle, cleared codes and test drove. I have refilled the tank twice and I am still getting the TIGHTEN FUEL CAP in the DIC with no CEL only a pending P0455. So I began the process of further investigation with making a smoke bucket and using about 3psi to smoke the system. I am only getting smoke out of the new VENT VALVE but of course I didn't rig up 12volts to command the VVS to close. I would still think other leaks could be viewed in the system though.
I found the GM general Drive Cycle on line. I have completed about 5 of these starting off first thing in the morning. I still receive a TIGHTEN FUEL CAP in DIC without CEL and only a Pending P0455 on the code reader.
Any other pointers would greatly be appreciated.....
Thanks,
