Suzuki 2006 SX4, Service Manual

Page: 934 / 1478

7B-69 Air Conditioning System: Automatic Type
DTC B1541: Back-Up Power Supply Circuit Malfunction
S6RW0C7224018
Wiring Diagram
DTC Detecting Condition and Trouble Area
NOTE
When checking DTC after connecting battery cable, be sure to turn ignition switch from OFF to ON and
from ON to OFF at least once, or DTC B1541 will be detected.
DTC Troubleshooting
12V
5V
WHT G20-7
2
3
1
G20
1 2 3 4 5 6 7 8 9 10 11 12 13 14
15 16 17 18 19 20 21 24 23 22 25 26 27 28 29 30
WHT/RED
[B]
I7RW01722011-01
[B]: Back-up power supply circuit 2. Main fuse
1. HVAC control module 3. Circuit fuse
DTC Detecting Condition Trouble Area
• Back-up power supply voltage is lower than specified value continuously.
• When connect battery with vehicle and then, turn ignition switch to ON
position for first time.
• Battery voltage supply circuit
• HVAC control module
Step Action Yes No
1 Was “Air Conditioning System Check” performed? Go to Step 2. Go to “Air Conditioning
System Check”.
2 DTC check
1) Turn ignition switch to ON position for 20 sec. or more.
2) Ignition switch turned OFF and connect scan tool to
DLC.
3) Turn ON ignition switch and check DTC.
Is there DTC B1541?
Go to Step 3. Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”.
3 Battery voltage supply circuit check
1) Disconnect connector from HVAC control module with
ignition switch turned OFF.
2) Check for proper connection to back-up power supply
circuit terminal of HVAC control module connector.
3) If OK, measure voltage between back-up power supply
circuit terminal of HVAC control module connector and
vehicle body ground.
Is voltage 10 – 14 V?
Substitute a known-
good HVAC control
module and recheck. Back-up power supply
circuit is open or
shorted to ground.