09-06-04-015B

Bulletin No.: 09-06-04-015B
Date: Nov-2013
Subject:
Information on Vehicles Sitting Outside on Dealer Lots for Extended Periods of Time with Hard Start or
Crank/No Start Condition
Models:
2009-2014 GM Cars and Trucks
Attention:
The Information in this bulletin applies only to unsold vehicles in dealer inventory and does not apply to
customer-owned vehicles that come in for service. DO NOT replace the ECM for this condition.
This bulletin has been revised to add the 2012-2014 model years. Please discard Corporate Bulletin Number 09-06-04-015A.
Some service department personnel may experience a hard start or a crank/no start condition with any of the above vehicles if they were delivered in the late
spring/summer/early fall time period, and have remained in inventory for an extended period of time through the winter. This condition is more noticeable in
regions of the country that experience cold climates. It may be caused by the vehicle's fuel tank containing a summer-blend quantity of fuel in it that was more
suitable to the warmer climate that existed when it was delivered. This condition is known as a fuel blend/season mismatch.
In the U.S., summer-blend fuel is federally mandated for use in the June 1st to September 15th time frame. Some states, California for example, have enacted
their own seasonal-blend regulations that lengthen this time period. Canada has similar regulations for fuel blends that are adjusted seasonally and
geographically. Summer-blend fuel has a different (lower) Reid vapor pressure (RVP) which contributes to it being more ecologically friendly, by reducing the
rate of evaporation. RVP is the standard used to measure the vapor pressure of gasoline at 38°C (100°F).
Fuels with a greater RVP evaporate more easily than those with a lower RVP. The main reason that summer-blend gasoline will not work well in the winter is
due to its low evaporation rate, which makes an engine difficult to start in cold ambient temperatures. This is the reason that the hard start, no/start condition
appears to go away when the vehicle is brought inside the service garage and has had the opportunity to warm up to ambient temperature. However, the
condition will repeat itself once the vehicle has been placed back outside on the lot and has cooled back down to a cold ambient temperature.
If the above condition exhibits itself as explained, or is suspected because the vehicle has been in inventory for an extended period of time, then refuel the
vehicle with enough fresh gasoline to start and run.
In order to prevent further occurrences, do not fill the fuel tank until the vehicle is ready for the Final Inspection & Preparation as indicated in the PreDelivery Inspection Form just prior to delivery of the vehicle to the customer.
If another cause for the crank/no start condition is suspected, then refer to Engine Cranks But Does Not Run in SI.
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may
occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools,
safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that
your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
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