Dtc B1552: Serial Communication Circuit Malfunction; Dtc B1553: Can Communication Circuit Malfunction - Suzuki GRAND VITARA Owner's Manual

7B-53 Air Conditioning System:

DTC B1552: Serial Communication Circuit Malfunction

DTC Detecting Condition and Trouble Area
Data received by HVAC control module from BCM is erroneous continuously. • BCM
DTC Confirmation Procedure
1) Connect scan tool to DLC with ignition switch turned OFF.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Check DTC.
DTC Troubleshooting
Step
1 Serial communication signal data 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", "Vehicle Speed", "Coolant
Temp" and "Outside Air Temp" varies displayed on scan
tool.
Is displayed each varies described varies in "Scan Tool
Data: "?
2 Serial communication signal check
1) Connect connectors to BCM and HVAC control module.
2) Using oscilloscope, check that serial communication
signal at "G30-5" is outputted referring to "Voltage
Check" of "Inspection of BCM and its Circuits: in Section
10B".
Is serial communication signal outputted at "G30-5" terminal
of BCM connector?

DTC B1553: CAN Communication Circuit Malfunction

DTC Detecting Condition and Trouble Area
HVAC control module receives error code from BCM continuously.
DTC Troubleshooting
Step
1 DTC check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Check ECM and BCM for DTC.
Is there DTC(s)?
DTC detecting condition
Action
DTC detecting condition
Action
Trouble area
• HVAC control module
Yes
Intermittent trouble.
Check for intermittent
referring to "Intermittent
and Poor Connection
Inspection: in Section
00".
HVAC control module
faulty.
Trouble area
• CAN communication circuit
• BCM
• ECM
• HVAC control module
Yes
Go to applicable DTC
diag. flow.
S5JB0A7204044
No
Go to Step 2.
BCM (included in
junction block
assembly) faulty.
S5JB0A7204045
No
Substitute a known-
good HVAC control
module and recheck.