The Drive Motor/Generator Control Module (DMCM)
coolant surge tank pressure cap must be fully installed
on the hybrid coolant surge tank.
Notice:If the pressure cap is not tightly installed,
coolant loss and possible damage to the Drive
Motor/Generator Control Module (DMCM) may occur.
Be sure the cap is properly and tightly secured.
Drive Motor/Generator Control
Module (DMCM) Cooling System
In addition to the regular cooling system, the vehicle
also has a cooling system for the DMCM system.
This system is serviced differently than the vehicle's
main cooling system. The DMCM cooling system
includes the DMCM coolant surge tank, DMCM surge
tank pressure cap, DMCM cooling pumps, hybrid
cooling radiator and the Drive Motor/Generator Control
Module (DMCM). The DMCM cooling system uses a
50/50 pre-mixed DEX-COOL™ coolant and deionized
water available at your dealer/retailer. See “Engine
Coolant” and“Cooling System” in the owner manual for
more information. When you decide it is safe to lift the hood, here is what
you will see:
A. Drive Motor/Generator
Control Module (DMCM)
B. Engine Coolant Surge Tank Pressure Cap
C. DMCM Coolant Surge Tank/Engine Coolant
Surge Tank D. DMCM Cooling
Hoses (Out of View)
E. DMCM Coolant Tank Pressure Cap
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Turn the DMCM coolant surge tank pressure cap
slowly counterclockwise (left) about one full turn.
Wait 30 seconds.
2. Then keep turning the DMCM coolant surge tankpressure cap slowly, and remove it.
3. Add the pre‐mixed DEX‐COOL™, available at your dealer/retailer, to the DMCM coolant surge tank
until the level reaches the FULL COLD mark.
4. Turn the ignition to ON/RUN without starting the engine. The hybrid cooling pumps will run and any
trapped air will purge to the surge tank. 5. Add the pre‐mixed DEX‐COOL™, available at your
dealer/retailer, until the coolant level is maintained
at the FULL COLD mark. This should take no
longer than two minutes of hybrid cooling pump
operation.
If the level cannot be kept at the FULL COLD
level, your vehicle may need service. See your
dealer/retailer.
6. Then replace the
DMCM coolant surge
tank pressure cap.
Be sure the pressure
cap is hand-tight and
fully seated.
Notice: Using tap water, cooling system sealers or
conditioners in an attempt to stop coolant leaks can
damage the DMCM and engine cooling systems.
Never use tap water, cooling system sealers or
conditioners in your cooling system.
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