Bulletin No.: 15-06-123-001A
Date: Feb-2016

Subject:

Information on the Use of Stop Leak Additives in the Coolant System

Models:

2014-2016 Cadillac ELR
2011-2017 Chevrolet Volt
2014-2016 Chevrolet Spark EV
2016 Chevrolet Malibu Hybrid
2012-2015 Opel Ampera

Attention:

This Bulletin also applies to any of the above models that may be Europe and Australia Export vehicles.

This Bulletin has been revised to add the 2017 Volt and the Malibu Hybrid, Opel Ampera models. Please discard Corporate
Bulletin Number 15-06-123-001.
The coolant systems in the models above use very small orifices in multiple areas (heater core filter, heater core, thermostat, radiators, heater plates in the HV
battery cells, etc.) for the cooling systems (Passenger Compartment Heater, Hybrid/EV Battery Pack Cooling, Hybrid Electronics Cooling). When a stop leak
product or other additives are used in the cooling systems these products will clog the small orifices reducing the flow of coolant. The coolant systems can have
adverse conditions requiring multiple part replacements including the entire HV battery.
Note: The flushing process described in SI is for maintenance and part replacements only. SI does not provide an adequate flushing procedure to remove the
stop leak product from the small orifices throughout the two cooling systems.

If a Stop Leak Product or Additives Have Been Used in the Passenger Compartment Heater System
If a stop leak product or additives are used in the passenger compartment heater system, the heater core, heater core outlet filter (if equipped), thermostat and
coolant must be replaced. The entire passenger compartment heater system must be removed to thoroughly flush/clean the stop leak/additive. If the stop
leak/additive cannot be properly flushed/cleaned or you can’t determine if the product was completely removed, then the part(s) must be replaced. If any of the
stop leak/additive is left behind, the vehicle may experience a repeat issue when the system is filled with coolant.

If a Stop Leak Product or Additives Have Been Used in Hybrid/EV Battery Pack Cooling System
If a stop leak product or additives are used in the Hybrid/EV battery pack cooling system, the coolant and Hybrid/EV battery pack may have to be replaced due
to codes set for clogged orifices, overheating, and/or isolation faults. Once the HV battery is replaced the entire HV battery coolant system has to be removed
to thoroughly flush/clean the stop leak/additive. If the stop leak/additive cannot be properly flushed/cleaned or you can’t determine if the stop leak/additive was
completely removed, then the part(s) must be replaced. If any of the stop leak/additive is left behind, the vehicle may experience a repeat issue when the
system is filled with coolant.

If a Stop Leak Product or Additives Have Been Used in the Hybrid Electronics Cooling System
If a stop leak product or additives are used in the Hybrid Electronics Cooling System, the electronic control modules may have to be replaced. The entire Hybrid
Electronics Cooling System must be removed to thoroughly flush/clean the stop leak/additive. If the stop leak/additive cannot be properly flushed/cleaned or you
can’t determine if the product was completely removed, then the part(s) must be replaced. If any of the stop leak/additive is left behind, the vehicle may
experience a repeat issue when the system is filled with coolant.
Note: The Passenger Compartment Heater, Hybrid/EV Battery Pack Cooling, Hybrid Electronics Cooling systems require a 50/50 mix of GM DEX-COOL® and
de-ionized water. This mixture is available in a pre-mix with bitterant, P/N 12378390 (U.S.) (in Canada, use 10953456). The pre-mixed coolant is no longer
available without the bitterant chemical. DO NOT use tap water or distilled water.

Warranty Information
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GM does not use any stop leak product or additives in the cooling systems on the Volt, ELR, Spark EV, Malibu Hybrid or Opel Ampera at the assembly plants. If
a dealership or customer installs a stop leak product or any type of additive to the cooling systems the cost to repair the vehicle will be the responsibility of the
dealership or customer.
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.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

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