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Home >> Suzuki >> 2007 >> SX4 Base, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 149 (Air Conditioning System) >> Diagnostic Information And Procedures >> DTC B1552: Serial Communication Circuit Malfunction >> DTC Troubleshooting
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DTC Troubleshooting

WARNING: This page is about a different car, the 2007 Suzuki Grand Vitara and 2006 Suzuki Grand Vitara. However, it is still accessible from the selected car via links, so may be relevant.
DTC TROUBLESHOOTING CHART

Step Action YES NO
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? 
Intermittent trouble. Check for intermittent referring to INTERMITTENT AND POOR CONNECTION INSPECTION . Go to Step 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 .

Is serial communication signal outputted at "G30-5" terminal of BCM connector? 
HVAC control module faulty. BCM (included in junction block assembly) faulty.