Suzuki Grand Vitara JB627. Manual - part 267

7-1 Precautions: 

HVAC

Precautions

Precautions

Precautions for HVAC

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Air Bag Warning
Refer to “Air Bag Warning in Section 00”.

A/C System Caution
Refer to “A/C System Caution in Section 00”.

Precautions on Servicing A/C System
Refer to “Precautions on Servicing A/C System in Section 7B”.

Precautions on Servicing Compressor
Refer to “Precautions on Replenishing Compressor Oil in Section 7B”.

Heater and Ventilation:  7A-1

HVAC

Heater and Ventilation

General Description

Heater and Ventilation Construction

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The heater, an in and out air selectable-type hot water heater, is so constructed that it is possible to assure an 
agreeable ventilation at all times by providing the ventilator air outlets at the center and both sides (right and left) of the 
instrument panel, the hot air outlet at a place close to the feet of front passengers, and the defroster air outlets at 
places, right and left, along the windshield glass.
The heater and ventilation consist of the following parts.

7

7

2

2

5

5

6

6

6

6

9

9

8

8

12

3

4

10

11

11

7

7

1

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1. HVAC unit

4. Defroster duct

7. Foot air

10. Fresh air 

2. Rear duct

5. Side ventilation louver

8. Defroster air

11. Recirculation air 

3. Ventilator duct

6. Ventilation air

9. Demister air

12. Center ventilation louver

7A-2 Heater and Ventilation: 

Body Ventilation Construction

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The body ventilation system of this vehicle has a fresh 
air intake (1) located at the cowl top panel. When fresh 
air intake air selector is at FRE position (fresh), 
ventilating air is drawn into the interior from the cowl 
center garnish and drawn out from the ventilator outlet 
(2) provided at each side body outer panel (both right 
and left side).

On-Board Diagnostic System Description (for 
Vehicle without A/C)

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HVAC control module (for vehicle without A/C) detects 
malfunction, which may occur in the following area. 
When HVAC control module detects any malfunction, the 
REC (recirculation) indicator light (4) flashes on and off 
continuously after turning ignition switch to ON position.
• ECT sensor
• CMP sensor
• Wheel speed sensor
• Temperature control actuator
• Air flow control actuator
• Air intake control actuator
• Temperature selector of HVAC control module
• Blower speed selector of HVAC control module
• Serial communication line
• CAN communication line
DTC can be checked by either one of the following ways.
• DTC can be checked by using SUZUKI scan tool (2) 

connected to DLC (1).

• Without using SUZUKI scan tool, DTC can be 

checked by reading the flashing pattern of both the 
FRE (fresh) indicator light (3) and the REC 
(recirculation) indicator light (4).

• Pressing DEF (defogger) switch (5) alternates display 

of current DTC and history DTC.

• DEF indicator light (6) remains off when display is in 

current DTC and it lights up when display is in history 
DTC.

HVAC Control System Description (for Vehicle 
without A/C)

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For CAN communication system, refer to description on 
“CAN Communication System Description in Section 
1A”.
When following data are sent from control modules to 
BCM through CAN communication, they are sent from 
BCM to HVAC control module through serial 
communication line.
• Engine coolant temperature
• Engine Speed
• Wheel speed (Vehicle speed)
HVAC control module has a function to make initial 
settings of temperature control actuator, air intake 
actuator and air flow actuator.
For vehicle without A/C, HVAC control module uses 
engine speed signal so that temperature control 
actuator, air intake actuator and air flow actuator can 
make initial setting for door position.
Initial settings of actuators are automatically made when 
engine is started for the first time after battery is 
connected.
When initial settings are made, each actuator is forced to 
operate for about 15 seconds continuously.

2

1

2

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3

4

5

6

1

2

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Heater and Ventilation:  7A-3

Schematic and Routing Diagram

Heater and Ventilation Wiring Circuit Diagram

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Refer to “A/C System Wiring Circuit Diagram in Section 7B”.

Electronic Control Input / Output Diagram (for Vehicle without A/C)

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Temperature selector

MODE (air flow) selector

Blower speed selector

Air intake selector

Wheel 
speed 
sensor

Blower motor controller

Temperature control actuator

Air flow control actuator

Air intake control actuator

BCM

ABS control module or
ESP® control module

Data link connector

HVAC control module

CPU

ECT sensor

ECM

CMP sensor

*

*

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*: CAN communication