HVAC Control System - General Information

• Specifications
  • General Specifications
  • Torque Specifications
• Description And Operation
  • Climate Control System
    • Climate Control System
    • Principles of Operation
      • Notes
      • Heat Transfer
      • Latent Heat of Vaporization
      • Relative Humidity
      • Effects of Pressure on Boiling or Condensation
    • Compressor Anti-Slugging Strategy
    • The Refrigerant Cycle
      • Notes
      • Electronic Manual Temperature Control System
      • Electronic Automatic Temperature Control System
      • Auxiliary Climate Control System
    • System Airflow Description - EMTC
      • Max A/C
      • Panel
      • Panel/Floor
      • Off
      • Floor
      • Floor/Defrost
      • Defrost
    • System Airflow Description - EATC
      • Auto
      • Off
      • Panel
      • Panel/Floor
      • Floor
      • Floor/Defrost
      • Defrost
• Diagnosis And Testing
  • Climate Control System
    • Notes
    • Special Tool(s)
    • Inspection and Verification
    • Electronic Automatic Temperature Control Module - Diagnostic Methods
      • Notes
      • Electronic Automatic Temperature Control Module On-Demand Self-Test
      • Electronic Automatic Temperature Control Module - Retrieve Continuous DTCs
    • Diagnostic Trouble Code Index
      • Electronic Automatic Temperature Control (EATC) Module Diagnostic Trouble Code (DTC) Index
      • Smart Junction Box (SJB) Diagnostic Trouble Code (DTC) Index
    • Symptom Chart
    • Connector Circuit Reference
    • Pinpoint Tests
      • Pinpoint Test A: DTC B1251 OR DTC B1253 - A/C In-Vehicle Temperature Sensor Open Circuit or Short to Ground
        • Normal Operation
        • Possible Causes
        • Pinpoint Test A: DTC B1251 Or DTC B1253 - A/C In-Vehicle Temperature Sensor Open Circuit Or Short To Ground
      • Pinpoint Test B: DTC B2796, DTC B2795, DTC B2426 or DTC B2427 - Solar Radiation Sensor Open Circuit or Short to Ground
        • Normal Operation
        • Possible Causes
        • PINPOINT TEST B: DTC B2796, DTC B2795, DTC B2426 or DTC B2427 - SOLAR RADIATION SENSOR OPEN CIRCUIT OR SHORT TO GROUND
      • Pinpoint Test C: DTC B1242 Air Inlet Door Failure
        • Normal Operation
        • Possible Causes
        • Pinpoint Test C: DTC B1242 Air Inlet Door Failure
      • Pinpoint Test D: DTC B1263 Mode Door Failure/Incorrect/Erratic Direction of Airflow From Outlet(s)
        • Normal Operation
        • Possible Causes
        • Pinpoint Test D: DTC B1263 Mode Door Failure/Incorrect/Erratic Direction Of Airflow From Outlet(S)
      • Pinpoint Test E: No Communication With The Electronic Automatic Temperature Control (EATC) Module
        • Normal Operation
        • Possible Causes
        • Pinpoint Test E: No Communication With The Electronic Automatic Temperature Control (EATC) Module
      • Pinpoint Test F: The EATC System is Inoperative, Intermittent or Incorrect Operation
        • Notes
        • Normal Operation
        • Possible Causes
        • Pinpoint Test F: The EATC System Is Inoperative, Intermittent Or Incorrect Operation
      • Pinpoint Test G: Insufficient, Erratic or No Heat
        • Normal Operation
        • Possible Causes
        • Pinpoint Test G: Insufficient, Erratic Or No Heat
      • Pinpoint Test H: The A/C Does Not Operate/Does Not Operate Correctly
        • Normal Operation
        • Possible Causes
        • Pinpoint Test H: The Air Conditioning (A/C) Is Inoperative/Does Not Operate Correctly
      • Pinpoint Test I: The Air Conditioning (A/C) Is Always On
        • Normal Operation
        • Possible Causes
        • Pinpoint Test I: The Air Conditioning (A/C) Is Always On
      • Pinpoint Test J: DTC B2266 or B2267: Temperature Blend Door Open/Short to Ground/Temperature Control Is Inoperative/Does Not Operate Correctly
        • Normal Operation
        • Door actuator feed A circuits
        • Door actuator feed B circuits
        • Door actuator return circuits
        • Door actuator reference circuits
        • Door actuator feedback circuits
        • Possible Causes
        • PINPOINT TEST J: DTC B2266 or B2267: TEMPERATURE BLEND DOOR OPEN/SHORT TO GROUND/TEMPERATURE CONTROL IS INOPERATIVE/DOES NOT OPERATE CORRECTLY
      • Pinpoint Test K: The Blower Motor Is Inoperative -EMTC
        • Normal Operation
        • Possible Causes
        • Pinpoint Test K: The Blower Motor Is Inoperative -EMTC
      • Pinpoint Test L: The Blower Motor Does Not Operate Correctly -EMTC
        • Normal Operation
        • Possible Causes
        • Pinpoint Test L: The Blower Motor Does Not Operate Correctly -EMTC
      • Pinpoint Test M: The Blower Motor Is Inoperative - EATC
        • Normal Operation
        • Possible Causes
        • Pinpoint Test M: The Blower Motor Is Inoperative - EATC
      • Pinpoint Test N: The Blower Motor Does Not Operate Correctly - EATC
        • Normal Operation
        • Possible Causes
        • Pinpoint Test N: The Blower Motor Does Not Operate Correctly - EATC
      • Pinpoint Test O: The Auxiliary Blower Motor Is Inoperative
        • Normal Operation
        • Possible Causes
        • Pinpoint Test O: The Auxiliary Blower Motor Is Inoperative
      • Pinpoint Test P: The Auxiliary Blower Motor Does Not Operate Correctly
        • Normal Operation
        • Possible Causes
        • Pinpoint Test P: The Auxiliary Blower Motor Does Not Operate Correctly
      • Pinpoint Test Q: The Auxiliary Temperature Control Only Is Inoperative/Does Not Operate Correctly
        • Normal Operation
        • Possible Causes
        • Pinpoint Test Q: The Auxiliary Temperature Control Only Is Inoperative/Does Not Operate Correctly
      • Pinpoint Test R: The Auxiliary Panel/Floor Control Only Is Inoperative/Does Not Operate Correctly
        • Normal Operation
        • Possible Causes
        • Pinpoint Test R: The Auxiliary Panel/Floor Control Only Is Inoperative/Does Not Operate Correctly
      • Pinpoint Test S: The Auxiliary Temperature and Panel/Floor Control Is Inoperative/Does Not Operate Correctly
        • Normal Operation
        • Possible Causes
        • Pinpoint Test S: The Auxiliary Temperature And Panel/Floor Control Is Inoperative/Does Not Operate Correctly
    • Component Tests
      • Blower Motor Resistor
      • Auxiliary Blower Motor Resistor
    • In-Vehicle Temperature Sensor - EATC
    • Heater Core
      • Notes
      • Heater Core - Plugged
      • Heater Core - Pressure Test
      • Heater Core - Bench Test
    • Evaporator/Condenser Core - On-Vehicle Leak Test
    • A/C Compressor - External Leak Test
• General Procedures
  • Air Conditioning (A/C) System Check - Retail Procedure
    • Notes
    • Visual inspection
  • Spring Lock Coupling
    • Special Tool(s)
    • Material
    • Disconnect
    • Cleaning
    • Connect
  • Air Conditioning Line (Peanut) Fitting
    • Disconnect
    • Connect
  • Refrigerant System Tests
    • Special Tool(s)
    • Procedure 1 - Ambient Temperature At or Below 38°C (100°F)
    • Procedure 2 - Ambient Temperature Above 38°C (100°F)
    • Diagnostic Table
  • A/C Clutch Air Gap Adjustment
  • Electronic Leak Detection
    • Special Tool(s)
    • Leak Detection Procedure
  • Fluorescent Dye Leak Detection
    • Special Tool(s)
    • Fluorescent Dye Detection
    • Fluorescent Dye Injection - Using an A/C Refrigerant Center and Dye Injector
    • Fluorescent Dye Injection - Using a Dye Injector Loop Kit
  • Air Conditioning (A/C) System Recovery, Evacuation and Charging
    • Special Tool(s)
    • Material
    • Refrigerant System Recovery
    • Refrigerant System Evacuation Using an R-134a Service Center
    • Refrigerant System Evacuation Using an R-134a Manifold Gauge Set
    • Refrigerant System Charging Using an R-134a Service Center
    • Refrigerant System Charging
  • Air Conditioning (A/C) System Flushing
    • Special Tool(s)
    • Material
    • System Flushing
  • Refrigerant System Filtering Following Air Conditioning (A/C) Compressor Installation
    • Special Tool(s)
    • Material
    • Refrigerant System Filtering
  • Refrigerant Oil Adding
    • Special Tool(s)
    • Material
    • Refrigerant Oil Adding
      • Notes
      • Refrigerant Oil Adding for New A/C Compressor Installation
      • Refrigerant Oil Adding for New Suction Accumulator or Receiver/Drier Installation
      • Oil Injection Using a Dye/Lubricant Injector
  • Refrigerant Identification Testing
    • Special Tool(s)
    • Refrigerant Identification
    • Contaminated Refrigerant Handling