Dtc B1504: Sunload Sensor And/Or Its Circuit Malfunction - Suzuki Swift Sport 2004 Service & Repair Manual

7B-52 Air Conditioning System: Automatic Type
Step
7 Evaporator temperature sensor check
1) Check evaporator temperature sensor referring to
"Evaporator Thermistor (Evaporator Temperature
Sensor) Inspection".
Is it in good condition?

DTC B1504: Sunload Sensor and/or Its Circuit Malfunction

Wiring Diagram
2
YEL/BLK
1. HVAC control module
DTC Detecting Condition and Trouble Area
Sunload sensor signal voltage is higher than or lower than specified value for
specified time continuously.
DTC Troubleshooting
Step
1 Sunload sensor power supply circuit check
1) Disconnect sunload sensor connector.
2) Check for proper connection to sunload sensor at "PNK"
and "YEL/BLK" 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?
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 "G52-2" and "G52-5" terminals.
3) If OK, measure resistance between "PNK" wire terminal
of sunload sensor connector and "G52-2" terminal of
HVAC control module connector.
Is resistance below 5
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?
Action
1
5V
PNK
G52-2
G52-5
DTC Detecting Condition
Action
Ω
?
Yes
HVAC control module
faulty.
G52
8 7 6 5 4 3 2 1
16 15 14 13 12 11 10 9
2. Sunload sensor
• Sunload sensor circuit
• Sunload sensor
• HVAC control module
Yes
Go to Step 5.
Go to Step 3.
Go to Step 4.
No
Evaporator temperature
sensor faulty.
S7RS0B7224012
G51
10 9 8 7 6 5 4 3 2 1
20 19 18 17 16 15 14 13 12 11
I5RS0A722012-01
Trouble Area
No
Go to Step 2.
"PNK" wire open or high
resistance circuit.
"PNK" wire shorted to
ground circuit.