Dtc B1541: Back-Up Power Supply Circuit Malfunction - Suzuki SX4 Service Manual

7B-66 Air Conditioning System: Automatic Type
DTC Troubleshooting
Step
1 Was "Air Conditioning System Check" performed?
2 DTC check
1) Clear DTC referring to "DTC Clearance: Automatic
Type".
2) Recheck DTC.
Are DTC B1520, B1521 and/or B1522 still detected?

DTC B1541: Back-Up Power Supply Circuit Malfunction

Wiring Diagram
2
3
WHT
[B]: Back-up power supply circuit
1. HVAC control module
DTC Detecting Condition and 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.
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
Step
1 Was "Air Conditioning System Check" performed?
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?
Action
1
[B]
WHT/RED G20-7
5V
12V
DTC Detecting Condition
Action
Yes
Go to Step 2.
Substitute a known
good HVAC control
module and recheck.
14 13 12 11 10 9 8
30 29 28 27 26 25 24
2. Main fuse
3. Circuit fuse
• Battery voltage supply circuit
• HVAC control module
Yes
Go to Step 2.
Go to Step 3.
No
Go to "Air Conditioning
System Check:
Automatic Type".
Intermittent trouble.
Check for intermittent
referring to "Intermittent
and Poor Connection
Inspection in Section
00".
S7RW0A7224018
G20
7 6 5 4 3
23 22 21 20 19 18 17
Trouble Area
No
Go to "Air Conditioning
System Check:
Automatic Type".
Intermittent trouble.
Check for intermittent
referring to "Intermittent
and Poor Connection
Inspection in Section
00".
2 1
16 15
I7RW01722011-01