090604015C

File in Section:
Bulletin No.:
Service Bulletin
Date:
06 - Engine
09-06-04-015C
March, 2018
INFORMATION
Subject:
Information on Vehicles Sitting Outside on Dealer Lots for Extended Periods of Time
with Hard Start or Crank/No Start Condition
Models:
2018 and Prior GM Passenger 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 2015-2018 Model Years. Please discard Corporate
Bulletin Number 09-06-04-015B.
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
Pre-Delivery 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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