UI Bulletin #117
Subject: Improper Engine Block Heater (Option
K05) Usage - Continuous Power
Models Chevrolet Express Cut-away Vans
Affected: Chevrolet Silverado Chassis Cab
GMC Savana Cut-away Vans
GMC Sierra Chassis Cab
Upfitted as an Ambulance (YF2)
Model Years: 2003 and beyond
Date: July 16, 2014
Revision July 16, 2014
Date:

ADVISORY:
This bulletin refers to General Motors Service Information Bulletin (TBD) – GM Dealers
should refer to the bulletin for more information.
Condition/Concern:
General Motors has identified vehicles with the optional Engine Block Heater (Option Code
K05), standard on all Duramax Diesel engines, where the fleet customer, dealer, or
secondary vehicle manufacturers/upfitters have plugged the engine block heater into an onboard “AC” power source providing continuous 110v power to the heater resulting in
electrical failure, shorting of wires, overheating of the system, and possibly engine
compartment fires.
Specifically, fleet customers, dealers, and secondary vehicle manufacturers/upfitters for
ambulance bodies are reminded that the Engine Block Heater usage is only for inclement
weather conditions specific to assisting with cold weather starts – not for continual usage or
usage during non-cold weather conditions.

Repair/Recommendation:
As shipped from GM, the available Engine Block Heater Cord is furled up and attached under
hood as illustrated in Figure 1 (item #2 & #3).
Fleet customers, dealers, and secondary vehicle manufacturers/upfitters are reminded that
the Regular Production Option (RPO) K05 Block Heater is to be used for Intermittent Cold
Ambient starts when the outside temperature is between -18 degrees C (-0 degrees F) and 29 degrees C (-20 degree F) – not to be continuously plugged into an “A/C” source.

General Motors Upfitter Integration
http://www.gmupfitter.com • 1-800-875-4742 (Upfitter Hotline)
Bulletin #117
5/23/2012

P a g e |1

July 16, 2014

Disclaimer: GM Upfitter Integration Technical 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 and/or modification of a vehicle. These 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. Contact GM Upfitter Integration for information on whether the information is applicable your vehicle.

UI Bulletin #117

Figure 1

General Motors Upfitter Integration
http://www.gmupfitter.com • 1-800-875-4742 (Upfitter Hotline)
Bulletin #117
5/23/2012

P a g e |2

July 16, 2014

Disclaimer: GM Upfitter Integration Technical 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 and/or modification of a vehicle. These 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. Contact GM Upfitter Integration for information on whether the information is applicable your vehicle.