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HOMESERVICE MANUALSLINCOLN2009NAVIGATOR L RWDREPAIR AND DIAGNOSISHEATING, VENTILATION & A/C (HVAC)HVAC CONTROL SYSTEMSHVAC CLIMATE CONTROL SYSTEM - GENERAL INFORMATION AND DIAGNOSTICSDIAGNOSIS AND TESTINGCLIMATE CONTROL SYSTEMSYMPTOM CHART - CLIMATE CONTROL SYSTEMS
2009 Lincoln Navigator L RWD

Symptom Chart - Climate Control Systems

2009 Lincoln Navigator L RWDSECTION Symptom Chart - Climate Control Systems
NOTE: Some PCM DTCs may inhibit A/C operation. If any PCM DTCs are retrieved, diagnose those first. Refer to PCM DTC CHART .
POSSIBLE CONDITION CHART

Condition Possible Sources Action
  • No communication with the HVAC module - Dual Automatic Temperature Control (DATC) or HVAC module - Electronic Manual Temperature Control (EMTC)
  • Fuse(s)
  • Circuitry open
  • HVAC module communication network
  • Unable to duplicate the customer concern and no DTCs present
  • HVAC system and/or related components
  • Reduced outlet airflow
  • Circuitry short
  • A/C compressor clutch air gap
  • A/C cycling switch
  • A/C clutch relay
  • Blower motor
  • Blower motor control
  • Blower motor resistor
  • Blower motor switch
  • PCM
  • If the A/C compressor does not cycle, Go To PINPOINT TEST L .
  • For EMTC  systems, if the A/C compressor cycles normally, Go To PINPOINT TEST Q .
  • For DATC  systems, if the A/C compressor cycles normally, Go To PINPOINT TEST S .
  • The air inlet door is inoperative
  • Circuitry open/shorted
  • Door actuator
  • Air inlet door binding or stuck
  • HVAC module
  • Incorrect/erratic direction of airflow from outlets
  • Circuitry open/shorted
  • Door actuator
  • Mode door binding or stuck
  • HVAC module
  • Insufficient, erratic or no heat
  • Low engine coolant level
  • Engine overheating
  • Plugged or partially plugged heater core
  • Temperature blend door is binding or stuck
  • Temperature blend door actuator
  • Heater hose is kinked or binding
  • The A/C is inoperative
  • Fuse(s)
  • Circuitry open
  • A/C system discharged/low charge
  • PCM
  • HVAC module
  • A/C clutch relay
  • A/C compressor clutch air gap
  • A/C pressure transducer
  • Evaporator discharge temperature sensor
  • A/C clutch field coil
  • Battery Junction Box (BJB)
  • The A/C is always on - A/C compressor does not cycle
  • Circuitry shorted
  • PCM
  • A/C clutch relay
  • A/C compressor clutch air gap
  • A/C pressure transducer
  • Evaporator discharge temperature sensor
  • The A/C is always on - A/C mode always commanded ON
  • Circuitry shorted
  • PCM
  • HVAC module
  • A/C pressure transducer
  • Evaporator discharge temperature sensor
  • Temperature control is inoperative/does not operate correctly - EMTC  systems
  • Circuitry open/shorted
  • HVAC module
  • Temperature blend door is binding or stuck
  • Temperature blend door actuator
  • Temperature control is inoperative/does not operate correctly - DATC  systems
  • Circuitry open/shorted
  • HVAC module
  • Temperature blend door is binding or stuck
  • Temperature blend door actuator
  • The blower motor is inoperative - EMTC 
  • Fuse(s)
  • Circuitry open
  • A/C blower motor switch
  • Blower motor relay
  • A/C blower motor
  • HVAC module
  • BJB
  • The blower motor does not operate correctly - EMTC 
  • Circuitry open/shorted
  • A/C blower motor resistor
  • A/C blower motor switch
  • The blower motor is inoperative - DATC 
  • Fuse(s)
  • Circuitry short/open
  • Blower motor relay
  • A/C blower motor
  • HVAC module
  • A/C blower motor speed control
  • BJB 
  • The blower motor does not operate correctly - DATC 
  • Circuitry open/shorted
  • A/C blower motor speed control
  • HVAC module
  • The auxiliary blower motor is inoperative
  • Fuse(s)
  • Circuitry open
  • Auxiliary blower motor relay 1
  • Auxiliary blower motor resistor
  • Auxiliary blower motor
  • HVAC module
  • The auxiliary blower motor does not operate correctly
  • Fuse(s)
  • Circuitry open/shorted
  • Auxiliary blower motor relay 1
  • Auxiliary blower motor relay 2
  • Auxiliary blower motor relay 3
  • Auxiliary blower motor resistor
  • Rear auxiliary control
  • HVAC module
  • If the auxiliary blower motor does not operate correctly from both the front and rear auxiliary controls, Go To PINPOINT TEST U .
  • If the auxiliary blower motor does not operate correctly from the rear auxiliary controls only, Go To PINPOINT TEST X .
  • If the auxiliary blower motor does not operate correctly from the front auxiliary controls only, INSTALL a new HVAC module. REFER to CLIMATE CONTROL article. TEST the system for normal operation.
  • The auxiliary temperature control is inoperative/does not operate correctly using the front/rear auxiliary climate controls
  • Circuitry open/shorted
  • Auxiliary blend door actuator
  • HVAC module
  • If the auxiliary temperature control is inoperative/does not operate correctly from both the front and rear auxiliary controls, Go To PINPOINT TEST V .
  • If the auxiliary temperature control is inoperative/does not operate correctly from the rear auxiliary controls only, Go To PINPOINT TEST X .
  • If the auxiliary temperature control is inoperative/does not operate correctly from the front auxiliary controls only, INSTALL a new HVAC module. REFER To CLIMATE CONTROL article. TEST the system for normal operation.
  • The auxiliary panel/floor control is inoperative/does not operate correctly using the front/rear auxiliary climate controls
  • Circuitry open/shorted
  • Auxiliary mode door actuator
  • HVAC module
  • If the auxiliary panel/floor control is inoperative/does not operate correctly from both the front and rear auxiliary controls, Go To PINPOINT TEST W .
  • If the auxiliary panel/floor control is inoperative/does not operate correctly from the rear auxiliary controls only, Go To PINPOINT TEST X .
  • If the auxiliary panel/floor control is inoperative/does not operate correctly from the front auxiliary controls only, INSTALL a new HVAC module. REFER to CLIMATE CONTROL article. TEST the system for normal operation.
  • The auxiliary temperature, panel/floor and blower motor controls are inoperative/do not operate correctly using the rear auxiliary climate controls
  • Circuitry open/shorted
  • Rear auxiliary control
  • HVAC module
  • The dual temperature control is inoperative/does not operate correctly
  • Temperature blend door/actuator broken/binding
  • HVAC module
  • Low A/C refrigerant charge
  • CHECK that the A/C system pressure is above 290 kPa (42 psi). If the pressure is below 290 kPa (42 psi), REFER to FLUORESCENT DYE LEAK DETECTION . CHECK the temperature blend doors/actuators for a binding or broken condition. If no condition is found, INSTALL a new HVAC module. REFER to CLIMATE CONTROL article. TEST the system for normal operation.
  • The temperature set point does not repeat after turning the ignition switch OFF
  • Fuse
  • Circuitry short/open
  • HVAC module
  • VERIFY Smart Junction Box (SJB) fuse 15 (10A) is OK. If OK, CHECK circuit SBP15 (WH/RD) for a short or open and repair as necessary. If OK, INSTALL a new HVAC module. REFER to CLIMATE CONTROL article. TEST the system for normal operation.
  • The temperature display will not switch between Celsius and Fahrenheit
  • HVAC module
  • Instrument Cluster (IC)
  • If the IC  does not switch between English and Metric, REFER to INSTRUMENT CLUSTER AND PANEL ILLUMINATION article and diagnose.
  • If only the HVAC module does not switch between English and Metric, INSTALL a new HVAC module. REFER to CLIMATE CONTROL article. TEST the system for normal operation.
  • Inaccurate external temperature display
  • HVAC module
  • Ambient temperature sensor
  • REFER to Description and Operation of the DATC EXTERNAL TEMPERATURE DISPLAY . If the external temperature display is not operating as described and no DTC is present, REMOVE the sensor from the vehicle (leave connected) and submerge in ice bath (ice water with ice). While the sensor is submerged, REMOVE Smart Junction Box (SJB) fuses 15 (10A) and 37 (10A). After one minute, INSTALL both fuses and check the external temperature display. The reading should be within 3 degrees of freezing 0°C (32°F). If the display is still incorrect, INSTALL a new external temperature sensor and retest the system for normal operation. If the condition persists (and there are still no DTCs present), INSTALL a new HVAC module. REFER to CLIMATE CONTROL article. TEST the system for normal operation.
  • A/C pressure relief valve discharging
  • High system pressure
  • A/C pressure relief valve
  • CHECK the high side system pressure. If the pressure is below the A/C pressure relief valve open pressure, REPLACE the A/C pressure relief valve. If the system pressure is above the A/C pressure relief valve open pressure, REPAIR the system for a restriction.
RENDER: 1.0x

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