Suzuki Grand Vitara JB416 / JB420 / JB419. Manual - part 390

7B-51 Air Conditioning System: 

DTC B1521: Blower Speed Selector and/or Its Circuit Malfunction

S6JB0A7204020

DTC Detecting Condition and Trouble Area

DTC Confirmation Procedure

1) Connect scan tool to DLC with ignition switch turned OFF.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Turn blower speed selector to the light and left as far as it stops, repeat it 10 seconds.
4) Check DTC.

DTC Troubleshooting

DTC B1530: Air Intake Control Actuator (Position Sensor) and/or Its Circuit Malfunction

S6JB0A7204021

Wiring Diagram

DTC detecting condition

Trouble area

This DTC will be set when an internal malfunction is detected in the 
HVAC control module.
Blower speed selector signal voltage is more than and less than 
specified value for specified time continuously.

HVAC control module (blower speed selector)

Step

Action

Yes

No

1

DTC check
1) Connect scan tool to DLC with ignition switch turned 

OFF.

2) Turn ignition switch ON and clear DTC referring to “DTC 

Clearance”.

3) Turn ignition switch OFF position.
4) Turn ignition switch ON and check DTC referring to 

“DTC Check”.

Is there DTC B1521?

Go to Step 2.

Intermittent trouble. 
Check for intermittent 
referring to “Intermittent 
and Poor Connection 
Inspection in Section 
00”.

2

HVAC control module terminal check
1) Remove HVAC control module referring to “HVAC 

Control Module Removal and Installation in Section 7A”.

2) Check for proper connection of HVAC control module 

connector at all terminals.

Is it in good condition?

Substitute a known-
good HVAC control 
module and recheck.

Repair faulty condition.

12V

5V

M

5V

G52-22

G52-31

G52-32

G52-13

RED/WHT

G52-14

BLK/RED

GRN

WHT/GRN

ORN

[A]

2

3

4

1

13

14

22

32 31

I5JB0A720027-01

[A]: HVAC control module connector “G52” (harness side view)

3. To other actuators

1. HVAC control module

4. To other sensors

2. Air intake control actuator 

Air Conditioning System:  7B-52

DTC Detecting Condition and Trouble Area

NOTE
When DTC B1502, B1503, B1511 and B1512 are indicated together, it is that “BLK/RED” wire circuit 
open.

 

DTC Confirmation Procedure

1) Connect scan tool to DLC with ignition switch turned OFF.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Check DTC.

DTC Troubleshooting

DTC Detecting Condition

Trouble Area

Air intake control actuator position sensor signal voltage is more than or less 
than specified value for specified time continuously.

• Air intake control actuator circuit
• Air intake control actuator
• HVAC control module

Step

Action

Yes

No

1

Position sensor power supply circuit check
1) Disconnect air intake control actuator connector with 

ignition switch turned OFF.

2) Check for proper connection to air intake control actuator 

at “RED/WHT”, “WHT/GRN” and “BLK/RED” wire 
terminals.

3) If OK, measure voltage between “RED/WHT” wire 

terminal of air flow control actuator connector and 
vehicle body ground with ignition switch turned ON.

Is voltage 4 – 6 V?

Go to Step 6.

Go to Step 2.

2

Position sensor power supply circuit check
1) Disconnect temperature control actuator connector with 

ignition switch turned OFF.

2) Measure voltage between “RED/WHT” wire terminal of 

air intake control actuator connector and vehicle body 
ground with ignition switch turned ON.

Is voltage 4 – 6 V?

Temperature control 
actuator faulty.

Go to Step 3.

3

Position sensor power supply circuit check
1) Disconnect air flow control actuator connector with 

ignition switch turned OFF.

2) Measure voltage between “RED/WHT” wire terminal of 

air intake control actuator connector and vehicle body 
ground with ignition switch turned ON.

Is voltage 4 – 6 V?

Air flow control actuator 
faulty.

Go to Step 4.

4

Position sensor power supply circuit check
1) Disconnect connector from HVAC control module with 

ignition switch turned OFF.

2) Check for proper connection to HVAC control module 

connector at “G52-14”, “G52-22” and “G52-13” 
terminals.

3) If OK, measure resistance between “RED/WHT” wire 

terminal of air intake control actuator connector and 
“G52-14” terminal of HVAC control module connector.

Is resistance below 5 

Ω

?

Go to Step 5.

“RED/WHT” wire open 
or high resistance 
circuit.

7B-53 Air Conditioning System: 

5

Position sensor power supply circuit check
1) Measure resistance between “RED/WHT” wire terminal 

of air intake control actuator connector and vehicle body 
ground.

Is resistance infinity?

Go to Step 6.

“RED/WHT” wire 
shorted to ground 
circuit.

6

Position sensor power supply circuit check
1) Measure voltage between “RED/WHT” wire terminal of 

air flow control actuator connector and vehicle body 
ground with ignition switch turned ON.

Is voltage 0 V?

Go to Step 7.

“RED/WHT” wire 
shorted to other circuit.

7

Position sensor signal circuit check
1) Connect HVAC control module connector with ignition 

switch turned OFF.

2) Measure voltage between “WHT/GRN” wire terminal of 

air intake control actuator connector and vehicle body 
ground with ignition switch turned ON.

Is voltage 4 – 6 V?

Go to Step 11.

Go to Step 8.

8

Position sensor signal circuit check
1) Disconnect connector from HVAC control module with 

ignition switch turned OFF.

2) Measure resistance between “WHT/GRN” wire terminal 

of air intake control actuator connector and “G52-22” 
terminal of HVAC control module connector.

Is resistance below 5 

Ω

?

Go to Step 9.

“WHT/GRN” wire open 
or high resistance 
circuit.

9

Position sensor signal circuit check
1) Measure resistance between “WHT/GRN” wire terminal 

of air intake control actuator connector and vehicle body 
ground.

Is resistance infinity?

Go to Step 10.

“WHT/GRN” wire 
shorted to ground 
circuit.

10 Position sensor signal circuit check

1) Measure voltage between “WHT/GRN” wire terminal of 

air intake control actuator connector and vehicle body 
ground with ignition switch turned ON.

Is voltage 0 V?

Go to Step 11.

“WHT/GRN” wire 
shorted to other circuit.

11 Position sensor ground circuit check

1) Connect HVAC control module connector with ignition 

switch turned OFF.

2) Measure resistance between “BLK/RED” wire terminal of 

air intake control actuator connector and vehicle body 
ground.

Is resistance below 5 

Ω

?

Go to Step 12.

Go to Step 13.

12 Position sensor ground circuit check

1) Measure resistance between “G52-13” terminal of HVAC 

control module connector and vehicle body ground.

Is resistance below 5 

Ω

?

“BLK/RED” wire open or 
high resistance circuit.

HVAC control module 
faulty.

13 Air intake control actuator check

1) Check air intake control actuator referring to “Air Intake 

Control Actuator Inspection”.

Is it in good condition?

HVAC control module 
faulty.

Air intake control 
actuator faulty.

Step

Action

Yes

No

Air Conditioning System:  7B-54

DTC B1531: Air Intake Control Actuator and/or Its Circuit Malfunction

S6JB0A7204022

Wiring Diagram

DTC Detecting Condition and Trouble Area

DTC Confirmation Procedure

1) Connect scan tool to DLC with ignition switch turned OFF.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start A/C system and select air intake selector at “FRE” position.
4) Select air intake selector at “REC” position and wait for 1 min. or more.
5) Check DTC.

DTC Troubleshooting

12V

5V

M

5V

G52-22

G52-31

G52-32

G52-13

RED/WHT

G52-14

BLK/RED

GRN

WHT/GRN

ORN

[A]

2

3

4

1

13

14

22

32 31

I5JB0A720027-01

[A]: HVAC control module connector “G52” (harness side view)

3. To other actuators

1. HVAC control module

4. To other sensors

2. Air intake control actuator 

DTC Detecting Condition

Trouble Area

Difference between target opening and actual opening is more than specified 
value even though air intake control actuator has operated for 15 seconds.

• Air intake control actuator circuit
• Air intake control linkage
• Air intake control actuator
• HVAC unit
• HVAC control module

Step

Action

Yes

No

1

Visual check
1) Check if there is any obstruction in operating range of 

actuator linkage and if actuator linkage operates 
smoothly.

Is it in good condition?

Go to Step 2.

Obstruction in operating 
range of actuator 
linkage, actuator linkage 
faulty and/or internal 
fault of HVAC unit.

2

Wire harness check
1) Disconnect connector from air intake control actuator 

with ignition switch turned OFF.

2) Check for proper connection to temperature control 

actuator connector at “ORN” and “GRN” wire terminals.

3) If OK, measure voltage between “ORN” wire terminal of 

temperature control actuator connector and vehicle body 
ground with ignition switch turned ON when air intake 
selector is operation to FRE position.

Is voltage 10 – 14 V?

Go to Step 6.

Go to Step 3.