LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lincoln >> 2010 >> Navigator 4WD >> Repair and Diagnosis (Single Page) >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> HVAC - Climate Control System - General Information And Diagnostics >> Diagnosis And Testing >> Climate Control System >> Pinpoint Tests >> Pinpoint Test M: The Air Conditioning (A/C) is Always On - A/C Mode Always Commanded ON >> Pinpoint Test M: The Air Conditioning (A/C) Is Always On - A/C Mode Always Commanded On
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Pinpoint Test M: The Air Conditioning (A/C) Is Always On - A/C Mode Always Commanded On

NOTE: It is important to install relays in their correct position in the Battery Junction Box (BJB). Installing a relay incorrectly can cause wiring shorts or damage to modules. While carrying out diagnostics on BJB  relays, have only one BJB  relay removed at a time. Failure to follow these instructions can result in damage to the vehicle circuitry or to control modules.
NOTE: Before carrying out the following test, diagnose any HVAC, PCM or IC  DTCs.
  1. M1 CHECK THE AIR CONDITIONING COMPRESSOR CYCLING SWITCH (ACCS) PCM PID WITH THE A/C OFF 
    • Ignition ON.
    • Enter the following diagnostic mode on the scan tool: ACCS PCM PID.
    • Does the ACCS PCM PID read ON? 
    • Yes:  GO to M2  .
    • No:  For Electronic Manual Temperature Control (EMTC) systems, GO to  M3.

      For Dual Automatic Temperature Control (DATC) systems, GO to M2  .

  2. M2 CHECK THE AIR CONDITIONING SWITCH STATUS (CC_AC) HVAC PID WITH THE A/C OFF 
    • Enter the following diagnostic mode on the scan tool: CC_AC HVAC PID.
    • Does the CC_AC HVAC PID read DEPRESSED? 
    • Yes:  GO to M3  .
    • No:  GO to  M4.
  3. M3 CHECK THE HVAC MODULE CONNECTION 
    • Inspect the HVAC module connectors for:
      • corrosion.
      • pushed-out terminals.
      • damaged terminals.
    • Connect and correctly seat all the HVAC module connectors.
    • Clear the DTCs.
    • Operate the system and verify the concern is still present.
    • Is the concern still present? 
    • Yes:  INSTALL a new HVAC module. REFER to CLIMATE CONTROL . TEST the system for normal operation.
    • No:  The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
  4. M4 CHECK THE PCM CONNECTION 
    • Disconnect all the PCM connectors.
    • Inspect the module connectors for:
      • corrosion.
      • pushed-out terminals.
      • damaged terminals.
    • Connect and correctly seat all the PCM connectors.
    • Clear the DTCs.
    • Operate the system and verify the concern is still present.
    • Is the concern still present? 
    • Yes:  INSTALL a new PCM. TEST the system for normal operation.
    • No:  The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
scientia non olet · About LEMON Manuals