SES MIL Evap DTC And/Or Hard To Fill - keywords emission engine evap evaporative fuel large leak P0446 P0442 P0455 pressure purge solenoid tank vacuum vent
| Subject: | SES MIL Evap DTC And/Or Hard To Fill |
| Models: | 2007-2008 Cadillac Escalade, ESV, EXT |
| 2007-2008 Chevrolet Avalanche, Suburban, Tahoe |
| 2007-2008 GMC Yukon, Yukon XL, Yukon Denali, Yukon Denali XL |
This PI was superseded to update administrative details. Please discard PIT4347D.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Some owners may comment that the SES is illuminated and when checking for DTCs the ECM will have set an Evap DTC. While performing normal diagnostics it may be noticed there is excessive moisture/water/corrosion at the vent valve solenoid, vent valve pipes, and/or EVAP canister. The vent valve solenoid draws fresh air from near the top of the fuel filler pipe. In some situations, it is possible that water spray from the rear wheels may be drawn in though the vent valve pipe at the top of the fuel filler pipe.
Recommendation/Instructions:
GM engineering is aware of this concern and working on a permanent correction. At this time clean and/or replace the affected components to minimize the concern.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
