cooling VOLVO XC90 TWIN ENGINE HYBRID 2017 User Guide

MAINTENANCE AND SERVICING
515

NOTE
If the start battery is completely dischargedand the vehicle has no normal electrical func-tions, and the engine is then started using anauxiliary battery or battery charger, theStart/Stop function will be activated. Theengine can then be auto-stopped but may notauto-start again due to an insufficient chargelevel in the start battery.
To help ensure auto-start, the start batteryshould be charged first. At a temperature ofapprox. 60 °F (15 °C), the battery should becharged for at least 1 hour, preferably usingan external battery charger. At lower tempera-tures, the battery should be charged for3–4 hours.
If a charger is not available, it is advisable todisable the Start/Stop function until the bat-tery is sufficiently recharged.

Related information
•Start battery (p. 512)
Hybrid battery
The vehicle's electric motor is powered by arechargeable, maintenance-free, lithium-ionhybrid battery.
The vehicle cannot be started if the hybridbattery is completely discharged.
WARNING
The vehicle's hybrid battery may only be serv-iced or replaced by a trained and qualifiedVolvo service technician.

Battery coolant
The hybrid battery's cooling system has its ownexpansion tank.
Filling the hybrid battery's cooling system shouldonly be done by a trained and qualified Volvoservice technician.
Related information
•Charging the hybrid battery (p. 413)

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MAINTENANCE AND SERVICING
* Option/accessory, for more information, see Introduction.520
replaced by a trained and qualified Volvoservice technician.
Function[A]
Converter for controlling feed tothe rear axle electric motor5
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Control module for actuator forengaging/changing gears5
High Voltage Coolant Heatercontrol module5
Control module for: A/C, chargemodule, heat exchanger cut-offvalve, cut-off valve for coolantthrough the climate system
5
Hybrid battery control module;high-voltage converter for com-bined high-voltage generator/starter motor with 500 V–12 Vvoltage converter
5
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Converter for controlling feed tothe rear axle electric motor10
Function[A]
Hybrid battery control modulefor high-voltage converter forcombined high-voltage genera-tor/starter motor with 500 V–12V voltage converter
10
Charging module5
Cut-off valve for hybrid batterycoolant; coolant pump 1 forhybrid battery
10
Coolant pump for electric drivesystem10
Hybrid component cooling fan25
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Function[A]
Front USB socket*5
12-volt socket in the front tun-nel console15
12-volt socket on the rear side
of the tunnel consoleA
12-volt socket in the tunnel con-
sole between the rear seats B
15
12-volt socket in the cargo com-partment
USB sockets for iPad holdersB
15
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Heated windshield* driver sideShunt
Heated windshield* driver side40
Headlight washers*25
Windshield washer25
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MAINTENANCE AND SERVICING
540
Hood completely closed

Related information
•Engine compartment overview (p. 540)
•Door and seat belt reminders (p. 70)
Engine compartment overview
The engine compartment overview shows somemaintenance points.
Some of the components in the vehicle's electri-cal drive system are located in the engine com-partment.
WARNING
•Orange cables should only be handled bya trained and qualified Volvo service tech-nician.
•A number of the vehicle's componentsuse high voltage and can be very danger-ous if handled improperly.
•Do not touch any components that havenot been clearly described/explained inthis manual.
•Use caution when checking/refilling flu-ids in the engine compartment.
•The cooling fan (located at the front ofthe engine compartment, behind the radi-ator) may start or continue to operate (forup to 6 minutes) after the engine hasbeen switched off.
•Engine cleaning should only be done by aworkshop. If engine cleaning agents areused when the engine has been running,there may a fire risk.
•Before performing any operations in theengine compartment, the ignition shouldalways be completely switched off (inmode 0) and there should be no remotekeys in the passenger compartment. Thegear selector should be in the P (park)position. If the engine has been running,wait until it has cooled before touchingany components in the engine compart-ment.
•The distributor ignition system operatesat very high voltages. Special safety pre-

MAINTENANCE AND SERVICING
546
Refilling coolant
Coolant helps keep the gasoline engine at theproper operating temperature. The heat transfer-red from the engine to the coolant can be usedto warm the passenger compartment.
When refilling coolant, follow the instructions onthe package and use the recommended amountof coolant. Never fill the cooling system withwater only; this could lead to freezing, corrosionand engine damage.

WARNING
If the engine has been running, the coolantwill be very hot. Allow the engine to coolbefore opening the coolant expansion tank. Ifthis is not possible, open the cap very slowlyto allow pressure to dissipate.
Coolant expansion tank
Lift the rubber strip by pressing it inward inthe engine compartment.
Remove the plastic cover by folding out thecatch and lifting the cover upward.
Unscrew the expansion tank cap and addcoolant. The level should be between theMIN and MAX marks on the tank.
Put the other components back in place in thereverse order.
CAUTION
•High levels of chlorine, chlorides andother salts may cause corrosion in thecooling system.
•Only use coolants with corrosion protec-tion recommended by Volvo.
•The ratio of coolant to water is 50/50.
•Mix the coolant with tap water of drinka-ble quality.
•If maintenance is performed on the cool-ing system or if the coolant is replaced,flush the cooling system with clean waterbefore adding new a new coolant/watermixture.
•The engine may only be operated with aproperly filled cooling system. Otherwise,high temperatures and cracks in the cyl-inders may occur.

Related information
•Coolant specifications and volumes(p. 566)