Suzuki Grand Vitara JB416 / JB420. Manual - part 285

7B-31 Air Conditioning System: 

DTC B1502: Inside Air Temperature Sensor and/or Its Circuit Malfunction

S5JB0A7204033

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) Check DTC.

DTC Troubleshooting

NOTE
When DTC B1503, B1511, B1512 and B1530 are indicated together, it is possible that “BLK/RED” wire 
circuit open.

 

5V

BLU/BLK

G52-20
G52-13

BLK/RED

[A]

2

3

1

13

20

I5JB0A720020-01

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

2. Inside air temperature sensor

1. HVAC control module

3. To other sensors

DTC Detecting Condition

Trouble Area

Inside air temperature sensor signal voltage is more than or less than 
specified value for specified time continuously.

• Inside air temperature sensor circuit
• Inside air temperature sensor
• HVAC control module

Step

Action

Yes

No

1

Inside air temperature sensor signal circuit check
1) Disconnect inside air temperature sensor connector with 

ignition switch turned OFF.

2) Check for proper connection to inside air temperature 

sensor at “BLU/BLK” and “BLK/RED” wire terminals.

3) If OK, measure voltage between “BLU/BLK” wire 

terminal of inside air temperature sensor connector and 
vehicle body ground with ignition switch turned ON.

Is voltage 4 – 6 V?

Go to Step 5.

Go to Step 2.

2

Inside air temperature sensor signal 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 “G52-20” and “G52-13” terminals.

3) If OK, measure resistance between “BLU/BLK” wire 

terminal of inside air temperature sensor connector and 
“G52-20” terminal of HVAC control module connector.

Is resistance below 5 

Ω

?

Go to Step 3.

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

3

Inside air temperature sensor signal circuit check
1) Measure resistance between “BLU/BLK” wire terminal of 

inside air temperature sensor connector and vehicle 
body ground.

Is resistance infinity?

Go to Step 4.

“BLU/BLK” wire shorted 
to ground circuit.

Air Conditioning System:  7B-32

DTC B1503: A/C Evaporator Air Temperature Sensor and/or Its Circuit Malfunction

S5JB0A7204034

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) Check DTC.

4

Inside air temperature sensor signal circuit check
1) Measure voltage between “BLU/BLK” wire terminal of 

inside air temperature sensor connector and vehicle 
body ground with ignition switch turned ON.

Is voltage 0 V?

Go to Step 5.

“BLU/BLK” wire shorted 
to other circuit.

5

Inside air temperature sensor ground circuit check
1) Connect HVAC control module connector with ignition 

switch turned OFF.

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

inside air temperature sensor connector and vehicle 
body ground.

Is resistance below 5 

Ω

?

Go to Step 7.

Go to Step 6.

6

Inside air temperature 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.

7

Inside air temperature sensor check
1) Check inside air temperature sensor referring to “Inside 

Air Temperature Sensor Inspection”.

Is it in good condition?

HVAC control module 
faulty.

Inside air temperature 
sensor faulty.

Step

Action

Yes

No

5V

BLK/RED

WHT/BLK

G52-19
G52-13

[A]

2

3

1

13

19

I5JB0A720021-01

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

2. Evaporator temperature sensor

1. HVAC control module

3. To other sensors

DTC Detecting Condition

Trouble Area

Evaporator temperature sensor signal voltage is more than or less than 
specified value for specified time continuously.

• Evaporator temperature sensor 

circuit

• Evaporator temperature sensor
• HVAC control module

7B-33 Air Conditioning System: 

DTC Troubleshooting

NOTE
When DTC B1502, B1511, B1512 and B1530 are indicated together, it is possible that “BLK/RED” wire 
circuit open.

 

Step

Action

Yes

No

1

Evaporator temperature sensor signal circuit check
1) Disconnect evaporator temperature sensor connector 

with ignition switch turned OFF.

2) Check for proper connection to evaporator temperature 

sensor at “WHT/BLK” and “BLK/RED” wire terminals.

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

terminal of evaporator temperature sensor connector 
and vehicle body ground with ignition switch turned ON.

Is voltage 4 – 6 V?

Go to Step 5.

Go to Step 2.

2

Evaporator temperature sensor signal 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 “G52-19” and “G52-13” terminals.

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

terminal of evaporator temperature sensor connector 
and “G52-19” terminal of HVAC control module 
connector.

Is resistance below 5 

Ω

?

Go to Step 3.

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

3

Evaporator temperature sensor signal circuit check
1) Measure resistance between “WHT/BLK” wire terminal 

of evaporator temperature sensor connector and vehicle 
body ground.

Is resistance infinity?

Go to Step 4.

“WHT/BLK” wire 
shorted to ground 
circuit.

4

Evaporator temperature sensor signal circuit check
1) Measure voltage between “WHT/BLK” wire terminal of 

evaporator temperature sensor connector and vehicle 
body ground with ignition switch turned ON.

Is voltage 0 V?

Go to Step 5.

“WHT/BLK” wire 
shorted to other circuit.

5

Evaporator temperature sensor ground circuit check
1) Connect HVAC control module connector with ignition 

switch turned OFF.

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

evaporator temperature sensor connector and vehicle 
body ground.

Is resistance below 5 

Ω

?

Go to Step 7.

Go to Step 6.

6

Evaporator temperature 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.

7

Evaporator temperature sensor check
1) Check evaporator temperature sensor referring to “A/C 

Evaporator Temperature Sensor Inspection”.

Is it in good condition?

HVAC control module 
faulty.

Evaporator temperature 
sensor faulty.

Air Conditioning System:  7B-34

DTC B1504: Sunload Sensor and/or Its Circuit Malfunction

S5JB0A7204035

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) Check DTC.

DTC Troubleshooting

5V

PNK

YEL

G52-18

G52-12

[A]

2

1

12

18

I5JB0A720022-01

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

1. HVAC control module

2. Sunload sensor

DTC Detecting Condition

Trouble Area

Sunload sensor signal voltage is more than or less than specified value for 
specified time continuously.

• Sunload sensor circuit
• Sunload sensor
• HVAC control module

Step

Action

Yes

No

1

Sunload sensor power supply circuit check
1) Disconnect sunload sensor connector with ignition 

switch turned OFF.

2) Check for proper connection to sunload sensor at “PNK” 

and “YEL” wire terminals.

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

sunload sensor connector and vehicle body ground with 
ignition switch turned ON.

Is voltage 4 – 6 V?

Go to Step 5.

Go to Step 2.

2

Sunload 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 “G52-12” and “G52-18” terminals.

3) If OK, measure resistance between “PNK” wire terminal 

of sunload sensor connector and “G52-12” terminal of 
HVAC control module connector.

Is resistance below 5 

Ω

?

Go to Step 3.

“PNK” wire open or high 
resistance circuit.

3

Sunload sensor power supply circuit check
1) Measure resistance between “PNK” wire terminal of 

sunload sensor connector and vehicle body ground.

Is resistance infinity?

Go to Step 4.

“PNK” wire shorted to 
ground circuit.

4

Sunload sensor power supply circuit check
1) Measure voltage between “PNK” wire terminal of 

sunload sensor connector and vehicle body ground with 
ignition switch turned ON.

Is voltage 0 V?

Go to Step 5.

“PNK” wire shorted to 
other circuit.