Dtc B1546: A/C Refrigerant Pressure Malfunction; Dtc B1551: Serial Communication Circuit Malfunction - Suzuki Swift Sport 2004 Service & Repair Manual

DTC B1546: A/C Refrigerant Pressure Malfunction

DTC Detecting Condition and Trouble Area
A/C refrigerant pressure sensor signal voltage is lower than specified value
even though outside air temperature is higher than specified value for
specified time continuously.
DTC Troubleshooting
Step
1 A/C refrigerant pressure and outside air temperature
check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Start engine and select "DATA LIST" mode on scan tool.
3) Check "Refrigerant Pressure" and "Outside Air Temp"
varies displayed on scan tool.
Is displayed each varies described varies in "Scan Tool
Data"?
2 A/C system performance check
1) Check A/C system performance referring to "A/C System
Performance Inspection".
Is check result satisfactory?
3 A/C refrigerant pressure sensor check
1) Check A/C refrigerant pressure sensor referring to "A/C
Refrigerant Pressure Sensor and Its Circuit Inspection".
Is check result satisfactory?
4 Outside air temperature sensor check
1) Check outside air temperature sensor referring to
"Information Display (Clock) Removal and Installation in
Section 9C".
Is check result satisfactory?

DTC B1551: Serial Communication Circuit Malfunction

Wiring Diagram
2
G37-11
1. HVAC control module
DTC detecting condition
Action
1
12V
YEL G51-7
3
2. BCM
Air Conditioning System: Automatic Type 7B-63
• Insufficient of refrigerant
• A/C refrigerant pressure sensor
• Outside air temperature sensor
• HVAC control module
Yes
Go to Step 2.
Go to Step 3.
Go to Step 4.
HVAC control module
faulty.
G52
8 7 6 5 4 3 2 1 10
16 15 14 13 12 11 10 9 20
3. Information display
S7RS0B7224018
Trouble area
No
Check the amount of
refrigerant and system
for leaks.
Repair or replace
defective part.
A/C refrigerant pressure
sensor faulty.
Outside air temperature
sensor faulty.
S7RS0B7224019
G51
9 8 7 6 5 4 3 2 1
19 18 17 16 15 14 13 12 11
I5RS0A722016-01