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Pinpoint Test P: Insufficient Heat In Auto Start-Stop Mode Only

  1. Refer to Auto-Start-Stop System for schematic and connector information.

    Normal Operation and Fault Conditions 

    Cabin Heater Coolant Pump - vehicles equipped with Auto Start-Stop, REFER to: Climate Control System - Vehicles With: Electronic Manual Temperature Control (EMTC) - System Operation and Component Description .

    DTC Fault Trigger Conditions 

    DTC Description Fault Trigger Condition
    PCM P2600:00 Coolant Pump "A" Control Circuit/Open: No Sub Type Information This DTC sets when the PCM senses an open on the cabin heater coolant pump circuits.
    PCM P2601:00 Coolant Pump "A" Control Circuit Performance/Stuck Off: No Sub Type Information This DTC sets when the PCM senses any of the following conditions:
    Dry-Run leads to cabin heater coolant pump running without resistance
    Over Temperature
    Over/Under Voltage
    Impeller Stall
    Impeller Speed below minimum speed
    Internal Error
    PCM P2602:00 Coolant Pump "A" Control Circuit Low: No Sub Type Information This DTC sets when the PCM senses low voltage on the PWM circuit when commanding it high, indicating a short to ground to the cabin heater coolant pump.
    PCM P2603:00 Coolant Pump "A" Control Circuit High: No Sub Type Information This DTC sets when the PCM senses low voltage on the PWM circuit when commanding it high, indicating an open circuit to the cabin heater coolant pump.

    Possible Sources 

    • Wiring, terminals or connectors
    • Low coolant or air in the coolant system
    • Cabin heater coolant pump
    • PCM

    Visual Inspection and Pre-checks 

    • Inspect for loose or corroded PCM and A/C compressor connections.
    • Make sure BJB fuse 12 (15A) is OK.

  2. P1 CHECK THE CABIN HEATER COOLANT PUMP

    NOTE: The engine must be auto-stopped to request the cabin heater coolant pump on. Further information can be found in the Owner's Literature for full Auto Start-Stop enabling and disabling.

    • Start the vehicle and allow engine to reach normal operating temperatures.

    • Using the HVAC controls, select panel mode, set temperature to full hot and set blower speed to low.

    • Drive the vehicle above 3 mph (4 km/h).

    • Stop the vehicle on a level surface.

    • Make sure that the steering wheel is set to the straight ahead position.

    • Keep the transmission selector lever in position D, brake pedal pressed and doors closed.

    • Using a diagnostic scan tool, view PCM Parameter Identifications (PIDs).

    • Monitor the PCM coolant pump status (COOLPMP_A_STAT) PID for at least 1 minute.

    Does the cabin heater coolant pump turn on? 

    Yes  GO to  P6
    No  GO to  P2

  3. P2 CHECK THE CABIN HEATER COOLANT PUMP CIRCUITS FOR A SHORT TO VOLTAGE

    • Disconnect BJB fuse 12 (15A).

    • Disconnect PCM 2.0L C1381B.

    • Disconnect PCM 2.7L C1551E.

    • Disconnect 2.0L Cabin heater coolant pump C163.

    • Disconnect 2.7L Cabin heater coolant pump C1805.

    • Ignition ON.

    • Measure:

      2.0L 

      Positive Lead Measurement / Action Negative Lead
      C163-2
      GFD524953Courtesy of FORD MOTOR COMPANY
      		 Ground
      C163-3
      GFD524953Courtesy of FORD MOTOR COMPANY
      		 Ground

      2.7L 

      Positive Lead Measurement / Action Negative Lead
      C1805-2
      GFD524953Courtesy of FORD MOTOR COMPANY
      		 Ground
      C1805-3
      GFD524953Courtesy of FORD MOTOR COMPANY
      		 Ground

    Is there any voltage present? 

    Yes  REPAIR the circuit.
    No  GO to  P3

  4. P3 CHECK THE CABIN HEATER COOLANT PUMP CIRCUITS FOR A SHORT TO GROUND

    • Ignition OFF.

    • Measure:

      2.0L 

      Positive Lead Measurement / Action Negative Lead
      C163-2
      GFD524952Courtesy of FORD MOTOR COMPANY
      		 Ground
      C163-3
      GFD524952Courtesy of FORD MOTOR COMPANY
      		 Ground

      2.7L 

      Positive Lead Measurement / Action Negative Lead
      C1805-2
      GFD524952Courtesy of FORD MOTOR COMPANY
      		 Ground
      C1805-3
      GFD524952Courtesy of FORD MOTOR COMPANY
      		 Ground

    Are the resistances greater than 10, 000 ohms? 

    Yes  GO to  P4
    No  REPAIR the circuit.

  5. P4 CHECK THE CABIN HEATER COOLANT PUMP CIRCUITS FOR AN OPEN

    • Measure:

      2.0L 

      Positive Lead Measurement / Action Negative Lead
      C163-1
      GFD524952Courtesy of FORD MOTOR COMPANY
      		 Ground

      2.0L 

      Positive Lead Measurement / Action Negative Lead
      C163-2
      GFD524952Courtesy of FORD MOTOR COMPANY
      		 BJB fuse 12 cavity, component side

      2.0L 

      Positive Lead Measurement / Action Negative Lead
      C163-3
      GFD524952Courtesy of FORD MOTOR COMPANY
      		 C1381B-20

      2.7L 

      Positive Lead Measurement / Action Negative Lead
      C1805-1
      GFD524952Courtesy of FORD MOTOR COMPANY
      		 Ground

      2.7L 

      Positive Lead Measurement / Action Negative Lead
      C1805-2
      GFD524952Courtesy of FORD MOTOR COMPANY
      		 BJB fuse 12 cavity, component side

      2.7L 

      Positive Lead Measurement / Action Negative Lead
      C1805-3
      GFD524952Courtesy of FORD MOTOR COMPANY
      		 C1551E-60

    Are the resistances less than 3 ohms? 

    Yes  GO to  P5
    No  REPAIR the circuit.

  6. P5 CHECK THE CABIN HEATER COOLANT PUMP CIRCUITS FOR A SHORT TOGETHER

    • Measure:

      2.0L 

      Positive Lead Measurement / Action Negative Lead
      C163-1
      GFD524952Courtesy of FORD MOTOR COMPANY
      		 C163-2
      C163-1
      GFD524952Courtesy of FORD MOTOR COMPANY
      		 C163-3
      C163-2
      GFD524952Courtesy of FORD MOTOR COMPANY
      		 C163-3

      2.7L 

      Positive Lead Measurement / Action Negative Lead
      C1805-1
      GFD524952Courtesy of FORD MOTOR COMPANY
      		 C1805-2
      C1805-1
      GFD524952Courtesy of FORD MOTOR COMPANY
      		 C1805-3
      C1805-2
      GFD524952Courtesy of FORD MOTOR COMPANY
      		 C1805-3

    Is the resistance greater than 10, 000 ohms? 

    Yes  GO to  P6
    No  REPAIR the circuit.

  7. P6 CHECK THE ENGINE COOLANT LEVEL

    NOTE: Allow the engine to cool before checking the engine coolant level.

    • Visually inspect the engine coolant level at the degas bottle.

    Is the engine coolant level within specifications? 

    Yes  GO to  P7
    No  Pressure test the cooling system for leaks. Refer to the appropriate Engine Cooling article for the procedure.

  8. P7 CLEAR ALL PCM (POWERTRAIN CONTROL MODULE) DIAGNOSTIC TROUBLE CODES

    • Connect all disconnected connectors. Make sure they seat and latch correctly.

    • Ignition ON.

    • Using a diagnostic scan tool, CLEAR all PCM Diagnostic Trouble Codes (DTCs).

    • NOTE: The engine must be auto-stopped to request the cabin heater coolant pump on. Further information can be found in the Owner's Literature for full Auto Start-Stop enabling/disabling.

      Start the vehicle and allow engine to reach normal operating temperatures.

    • Using the HVAC controls, select panel mode, set temperature to full hot and set blower speed to low.

    • Drive the vehicle above 3 mph (4 km/h).

    • Stop the vehicle on a level surface.

    • Make sure that the steering wheel is set to the straight ahead position.

    • Keep the transmission selector lever in position D, brake pedal pressed and doors closed.

    • Using a diagnostic scan tool, view PCM Parameter Identifications (PIDs).

    • Monitor the PCM Coolant Pump 'A' Control Diagnostic Status (COOLPMP_A_STAT) PID for at least 1 minute.

    Does the cabin coolant pump turn on? 

    Yes  If the cabin coolant pump runs for 10 seconds on and 10 seconds off, PURGE the air from the coolant system. Refer to the appropriate Engine Cooling article for the procedure. If the cabin coolant pump runs normally, the system is operating correctly at this time. The concern may have been caused by pump connections. ADDRESS the root cause of any connector or pin issues.
    No  INSTALL a new cabin heater coolant pump. REFER to the appropriate procedure in REMOVAL AND INSTALLATION  . If the concern is still present, GO to  P8

  9. P8 CHECK FOR CORRECT PCM (POWERTRAIN CONTROL MODULE) OPERATION

    • Ignition OFF.

    • Disconnect and inspect all PCM connectors.

    • Repair:

      • corrosion (install new connector or terminals - clean module pins)
      • damaged or bent pins - install new terminals/pins
      • pushed-out pins - install new pins as necessary

    • Connect all PCM connectors. Make sure they seat and latch correctly.

    • Operate the system and determine if the concern is still present.

    Is the concern still present? 

    Yes  CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, Refer to PCM Guided Routine Testing .
    No  The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues.
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