Suzuki Grand Vitara JB416 / JB420 / JB419. Manual - part 373

7A-2 Heater and Ventilation: 

Body Ventilation Construction

S6JB0A7101002

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).

Additional Heater System Description (Diesel 
Engine Model)

S6JB0A7101005

This system, consisting of ECM, additional heater 
assembly and 3 relays, warms up the engine coolant 
which flows through the heater core while the engine is 
warmed up, thereby promoting interior heating. It is not 
activated during pre/post heating by glow plug. Not 
during pre/post heating by glow plug, it is activated on 
the following conditions.
• Ten seconds have passed after the engine start.
• The battery voltage is more than 12.2 V.
• The engine speed is more than 700 rpm.
• The engine coolant and the intake air temperature is 

as shown in the graph below.

2

1

2

I5JB0A710002-03

[A]: Engine coolant temperature (

°C)

[C]: ON

[B]: Intake air temperature (

°C)

[D]: OFF

0

0

5

10

10

-10

20

30

40

50

60

70

75

15

25

20

[B]

[A]

[C]

[D]

I5JB0B710001-03

Heater and Ventilation:  7A-3

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

S6JB0A7101003

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 lamp (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 lamp (3) and the REC 
(recirculation) indicator lamp (4).

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

of current DTC and history DTC.

• DEF indicator lamp (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)

S6JB0A7101004

For CAN communication system, refer to description on “CAN Communication System Description: For Petrol Engine 
Model 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.

3

4

5

6

1

2

I5JB0A710004-04

7A-4 Heater and Ventilation: 

Schematic and Routing Diagram

Heater and Ventilation Wiring Circuit Diagram

S6JB0A7102001

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

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

S6JB0A7102002

Additional Heater System Input / Output Diagram (Diesel Engine Model)

S6JB0A7102004

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

Additional heater relay
(diesel engine model)

HVAC control module

CPU

ECT sensor

ECM

CMP sensor

*

*

I6JB0A710001-03

*: CAN communication

Additional heater relay No.1 

Additional heater relay No.2 

Additional heater relay No.3 

CKP senser

IAT sencer

Battery voltage

ECT senser

ECM

I5JB0B710003-02

Heater and Ventilation:  7A-5

Component Location

Electronic Components Location for Heater (for Vehicle without A/C)

S6JB0A7103001

NOTE
The figure shows left-hand steering vehicle. For right hand steering vehicle, parts with (*) are installed 
at the opposite side.

 

2

3

1*

4*

5*

18

6

17

19

8

15

16

10

9

14

7

11

12

13

I6JB0B710001-01

1. Air intake control actuator

8. “DEF / FOOT” switch

15. “REC” indicator lamp

2. Temperature control actuator

9. “FOOT” switch

16. “FRE” indicator lamp

3. Air flow control actuator

10. “BI-LEVEL” switch

17. MODE selector

4. Blower motor

11. “VENT” switch

18. HVAC control module (for vehicle without A/C)

5. Blower motor controller

12. Theft deterrent light

19. “DEF” indicator lamp

6. Temperature selector

13. Blower speed selector / Air intake selector

7. “DEF” switch

14. Rear defogger switch