Suzuki 2006 SX4 Service Manual page 1004

7B-64 Air Conditioning System: Automatic Type
DTC Troubleshooting
NOTE
• When DTC B1502, B1503, B1504 and B1511 are indicated together, it is possible that sensor ground
circuit is open.
• When DTC B1511 is indicated together, it is possible that position sensor power supply circuit is
open.
Step
1 Was "Air Conditioning System Check" performed?
2 Wire harness check
1) Turn ignition switch to OFF position.
2) Disconnect connectors from air flow control actuator and
HVAC control module.
3) Check for proper connection to position sensor power
supply, signal and ground circuit terminals of air flow
control actuator and HVAC control module connectors.
4) If OK, check that position sensor of air flow control
actuator circuit is as follows.
• Wiring harness resistance of each position sensor
power supply, signal and ground circuit is less than 3
Ω
• Insulation resistance of each position sensor power
supply, signal and ground circuit is infinity between air
flow control actuator connector and vehicle body
ground
• Circuit voltage of each position sensor power supply,
signal and ground circuit is 0 - 1 V with ignition switch
turned ON
Are they in good condition?
3 Position sensor of air flow control actuator 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.
• Position sensor power supply terminal and position
sensor ground terminal of air flow control actuator
connector
• Position sensor signal terminal and position sensor
ground terminal of air flow control actuator connector
Is voltage 4.5 – 5.5 V?
4 Air flow control actuator check
1) Check position sensor of air flow control actuator for
performance referring to "Air Flow Control Actuator and
Its Circuit Inspection".
Is it in good condition?
Action Yes
Go to Step 2.
Go to Step 3.
Go to Step 4.
Substitute a known-
good HVAC control
module and recheck.
No
Go to "Air Conditioning
System Check".
Position sensor power
supply, signal circuit
and/or ground circuit are
open, short or high
resistance.
Go to Step 5.
Replace air flow control
actuator.