Suzuki XL7 2007 Service Manual page 1846

7A-32 Heating, Ventilation and Air Conditioning:
DTC B3933
Diagnostic Instructions
• Perform the "Diagnostic System Check - Vehicle Diagnostic Information: " prior to using this diagnostic procedure.
• Review "Strategy Based Diagnosis: " for an overview of the diagnostic approach.
• "Diagnostic Procedure Instructions - Vehicle Diagnostic Information: " provides an overview of each diagnostic
category.
DTC Descriptors
DTC B3933 13: Evaporator Air Temperature Voltage High Sensor
DTC B3933 14: Evaporator Air Temperature Voltage Low Sensor
Diagnostic Fault Information
Circuit
Evaporator Sensor Signal
Evaporator Low Reference Signal
1 - A/C compressor will not engage
Circuit/System Description
The HVAC control module supplies the evaporator
temperature sensor with a low reference circuit and 5-
volt signal circuit. The HVAC control module determines
the voltage drop across the sensor, which is proportional
to temperature. When the refrigerant temperature is low
the sensor resistance and voltage signal are high. When
the refrigerant temperature is high the sensor resistance
and voltage signal are low. The sensor works in
conjunction with a switch to meter the flow of refrigerant
therefore preventing the freezing of moisture that
condenses on the evaporator. An evaporator with little
refrigerant will starve causing insufficient cooling. An
evaporator flooded with refrigerant will also cause poor
cooling when there is too much liquid refrigerant that
cannot vaporize quickly.
Conditions for Running the DTC
The igniting is turned ON.
Conditions for Setting the DTC
The HVAC control module detects the evaporator
temperature sensor signal circuit is less than 0.443 volts
or greater than 4.55 volts.
Short to Open/High
Ground Resistance
B3933 13 B3933 14
— 1
Action Taken when the DTC Sets
The air conditioning (A/C) compressor will be disabled.
Conditions for Clearing the DTC
• The DTC will become history if the HVAC control
module no longer detects a failure.
• The history DTC will clear after 50 fault-free ignition
cycles.
• The DTC can be cleared with a scan tool.
Reference Information
Schematic Reference
"HVAC Schematics"
Connector End View Reference
"HVAC Connector End Views"
Description and Operation
"Air Temperature Description and Operation"
Electrical Information Reference
• "Circuit Testing: "
• "Connector Repairs: "
• "Testing for Intermittent Conditions and Poor
Connections: "
• "Wiring Repairs: "
Scan Tool Reference
• "Scan Tool Output Controls - HVAC - Automatic"
• "Scan Tool Data List - HVAC - Automatic"
• "Scan Tool Data Definitions - HVAC - Automatic"
Signal
Short to Voltage
Performance
B3933 14
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