Suzuki SX4 Service Manual page 1053

DTC Detecting Condition and Trouble Area
NOTE
When DTC B1502, B1503, B1511 and B1512 are indicated together, it is possible that sensor ground
circuit is open.
• Sunload sensor signal voltage is higher than or lower than specified value
for specified time continuously.
• Without sunlight
DTC Troubleshooting
Step
1 Was "Air Conditioning System Check" performed?
2 Wire harness check
1) Turn ignition switch to OFF position.
2) Disconnect connectors from sunload sensor and HVAC
control module.
3) Check for proper connection to each signal circuit
terminal and ground circuit terminal of sunload sensor
and HVAC control module connectors.
4) If OK, check that sunload sensor circuit is as follows.
• Wiring harness resistance of each sunload sensor
signal circuit and ground circuit is less than 3 Ω
• Insulation resistance of each sunload sensor signal
circuit and ground circuit between sunload sensor
connector and vehicle body ground is Infinity
• Circuit voltage of each sunload sensor signal circuit
and ground circuit is 0 – 1 V with ignition switch turned
ON
Are they in good condition?
3 Sunload sensor power supply voltage check
1) Connect connector to HVAC control module with ignition
switch turned OFF.
2) Turn ignition switch to ON position.
3) Measure voltage between signal terminal and ground
terminal of sunload sensor connector.
Is voltage 4.5 – 5.5 V?
4 Sunload sensor check
1) Check sunload sensor for performance referring to
"Sunload Sensor Inspection".
Is it in good condition?
DTC Detecting Condition
Action
Air Conditioning System: Automatic Type 7B-59
• Sunload sensor circuit
• Sunload sensor
• HVAC control module
Yes
Go to Step 2.
Go to Step 3.
Go to Step 4.
Substitute a known-
good HVAC control
module and recheck.
Trouble Area
No
Go to "Air Conditioning
System Check:
Automatic Type".
Sunload sensor power
supply circuit and/or
signal circuit are open,
short or high resistance.
Substitute a known-
good HVAC control
module and recheck.
Replace sunload
sensor.