Pinpoint Test L: The A/C (Air Conditioning) Is Inoperative With No Diagnostic Trouble Codes (DTCS)

Refer to MANUAL CLIMATE CONTROL SYSTEM for schematic and connector information.
Normal Operation and Fault Conditions

When an A/C request is received by the PCM, the A/C clutch is engaged when all of the following conditions are met:
- Excessively high or low refrigerant pressure from the A/C pressure transducer is not detected.
- Ambient air temperature is above approximately 0 deg. C (32. 0 deg. F).
- Evaporator temperature is above approximately 1 deg. C (33. 8 deg. F).
- Engine coolant temperature conditions are within normal parameters.
- Wide Open Throttle (WOT) condition is not present.
- Engine torque conditions are within normal parameters.
- Battery state of charge conditions are within normal parameters.
For more information on A/C Request, REFER to: Climate Control System - Vehicles With: Electronic Manual Temperature Control (EMTC) - System Operation and Component Description

Possible Sources
- Wiring, terminals or connectors
- A/C system discharged or low refrigerant charge
- Network concerns
- A/C pressure transducer
- Evaporator temperature sensor
- Engine temperature sensors
- A/C compressor clutch air gap
- A/C compressor clutch field coil
- A/C clutch relay [non-serviceable, part of the BJB]
- HVAC control module
Visual Inspection and Pre-checks
- Verify the A/C compressor belt is OK.
- Verify the A/C compressor clutch is engaged/operating.
NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector.
NOTE: Some Powertrain Control Module (PCM) Diagnostic Trouble Codes (DTCs) may inhibit Air Conditioning (A/C) operation. If any Powertrain Control Module (PCM) Diagnostic Trouble Codes (DTCs) are retrieved, diagnose those first. Refer to the appropriate DTC Index.

L1 VERIFY THE AIR CONDITIONING (A/C) CLUTCH OPERATION

Start the engine. Observe the outside temperature display for proper operation.

On the HVAC controls, set the temperature to full cold, select PANEL and select the A/C button (indicator on).

Does the A/C compressor clutch engage?

Yes	TEST the A/C system for normal operation. Carry out the Refrigerant System Tests. REFER to: Refrigerant System Tests - 2. 3L EcoBoost (199kW/270PS) REFER to: Refrigerant System Tests - 2. 7L EcoBoost (238kW/324PS)

GO to L2

L2 RESET THE OUTSIDE AIR TEMPERATURE (OAT)/AMBIENT AIR TEMPERATURE (AAT) SENSOR

Ignition OFF.

Wait 1 minute.

Ignition ON.

Using the FDRS diagnostic scan tool, follow the on screen prompts to reset the Outside Air Temperature (OAT)/Ambient Air Temperature (AAT) sensor data.

Start the engine.

On the HVAC controls, set the temperature to full cold, select PANEL and select the A/C button (indicator on).

Does the A/C compressor turn on?

Yes	TEST the A/C system for normal operation. Carry out the Refrigerant System Tests. REFER to: Refrigerant System Tests - 2. 3L EcoBoost (199kW/270PS) REFER to: Refrigerant System Tests - 2. 7L EcoBoost (238kW/324PS)

GO to L3

L3 CHECK THE A/C (AIR CONDITIONING) SYSTEM PRESSURE

NOTE: Static refrigerant pressure, under perfect conditions, should approximately reflect ambient air temperature. Do not rely upon the static refrigerant pressure alone to determine if the system is properly charged. Refer to the current Ford Web Based Technical Training courses for basic HVAC system refrigerant operation.

Ignition OFF.

Connect a manifold gauge set.

With a manifold gauge set connected, check for minimum A/C system pressure.

Is the A/C system pressure above 290 kPa (42 psi)?

Yes

GO to L4

No	CHECK the A/C system for leaks. REFER to: Air Conditioning (A/C) System Leak Test Using Forming Gas REFER to: Electronic Leak Detection REFER to: Fluorescent Dye Leak Detection After leak is repaired, RECHARGE the A/C system. REFER to: Air Conditioning (A/C) System Recovery, Evacuation and Charging

L4 CHECK THE COMMUNICATION NETWORK

Ignition ON.

Using a diagnostic scan tool, carry out the network test. REFER to: Controller Area Network (CAN) Module Communications Network

Do the BCMC, the HVAC control module, and the PCM (as applicable) pass the network test?

Yes

GO to L5

No	DIAGNOSE the BCMC, the HVAC control module or PCM does not communicate with the diagnostic scan tool. REFER to: Controller Area Network (CAN) Module Communications Network

L5 CHECK THE PCM (POWERTRAIN CONTROL MODULE) A/C (AIR CONDITIONING) PRESSURE SENSOR (ACP_PRESS) PARAMETER IDENTIFICATION (PID)

NOTE: The following pinpoint test step is tested in ambient temperature of approximately 21. 1 deg. C (70 deg. F). As ambient temperatures near 38 deg. C (100. 4 deg. F), the pressure value difference increases above +/- 15 psi (103 kPa) range.
- With a manifold gauge set connected, compare the pressure readings of the manifold gauge set and the
  Access the PCM and monitor the ACP_PRESS (kPa) PID
Are the pressure values of the manifold gauge set and the ACP_PRESS PCMPID, dependent upon ambient temperatures, within +/- 103 kPa (15 psi)?

Yes GO to L6

No DIAGNOSE the A/C pressure transducer. GO to Pinpoint Test A

L6 COMPARE THE HVAC (HEATING, VENTILATION AND AIR CONDITIONING) CONTROL MODULE EVAPORATOR TEMPERATURE (EVAP_TEMP) PARAMETER IDENTIFICATION (PID) TO THE PCM (POWERTRAIN CONTROL MODULE) AMBIENT AIR TEMPERATURE (AAT) PARAMETER IDENTIFICATION (PID)

Ignition OFF.

Allow the vehicle exterior and interior to stabilize to ambient temperature. This can take a soak period of at least 6 hours.

Ignition ON.

Using a diagnostic scan tool, monitor and record the
Access the PCM and monitor the AAT (Deg C) PID

Using a diagnostic scan tool, monitor and record the
Access the HVAC and monitor the EVAP_TEMP (Deg C) PID

Are the temperature values similar [typically within 18 deg. C or 30 deg. F of each other]?

Yes

GO to L7

No	DIAGNOSE the suspect temperature sensor. For Ambient Air Temperature (AAT) sensor or Outside Air Temperature Display concerns, REFER to: Instrumentation, Message Center and Warning Chimes For evaporator temperature sensor concerns, GO to Pinpoint Test F

L7 COMPARE THE PCM (POWERTRAIN CONTROL MODULE) INTAKE AIR TEMPERATURE (IAT) PARAMETER IDENTIFICATION (PID) AND THE OTHER TEMPERATURE SENSOR READINGS TO THE PCM (POWERTRAIN CONTROL MODULE) AMBIENT AIR TEMPERATURE (AAT) PARAMETER IDENTIFICATION (PID)

NOTE: Compare multiple engine sensor readings to the ambient temperature to determine sensors are reading correctly. A faulty sensor can cause the Powertrain Control Module (PCM) to disable the Air Conditioning (A/C) with or without a Diagnostic Trouble Code (DTC).
- Monitor the temperature Parameter Identifications (PIDs) (as applicable):
  - Access the PCM and monitor the AAT (Deg C) PID
  - Access the PCM and monitor the CAC_T (Deg C) PID
  - Access the PCM and monitor the CHT (Deg C) PID
  - Access the PCM and monitor the ECT (Deg C) PID
  - Access the PCM and monitor the IAT (Deg C) PID
  - Access the PCM and monitor the IAT2 (Deg C) PID
Are the temperature values similar [typically within 18 deg. C or 30 deg. F of each other]?

Yes GO to L8

No DIAGNOSE the suspect PCM temperature sensor. REFER to the appropriate Engine service information.

L8 CHECK THE HVAC (HEATING, VENTILATION AND AIR CONDITIONING) CONTROL MODULE A/C (AIR CONDITIONING) SWITCH (CC_SW_AC) PID (PARAMETER IDENTIFICATION) WITH THE A/C (AIR CONDITIONING) ON
- Access the HVAC and monitor the CC_SW_ACPID
- On the HVAC controls, select PANEL and then press the A/C button (indicator ON).
Does the PID display ON or Yes when the button is pressed?

Yes GO to L9

No GO to L16

L9 CHECK THE PCM (POWERTRAIN CONTROL MODULE) A/C (AIR CONDITIONING) REQUEST SIGNAL (AC_REQ) PARAMETER IDENTIFICATION (PID) WITH THE A/C (AIR CONDITIONING) ON
- Start the engine.
- Access the PCM and monitor the AC_REQPID
- On the HVAC controls, select PANEL and then press the A/C button (indicator ON).
Does the PID display ON or Yes when the button is pressed?

Yes GO to L10

No GO to L16

L10 CHECK THE PCM (POWERTRAIN CONTROL MODULE) A/C (AIR CONDITIONING) COMPRESSOR COMMANDED STATE (ACC_CMD) PARAMETER IDENTIFICATION (PID) WITH THE A/C (AIR CONDITIONING) COMMANDED ON
- Access the PCM and control the ACC_CMDPID
Does the A/C compressor turn on?

Yes GO to L17

No GO to L11

L11 CHECK THE A/C (AIR CONDITIONING) CLUTCH RELAY COIL CONTROL CIRCUIT FOR AN OPEN

Ignition OFF.

Disconnect PCM C175B (2. 3L) or C1551B (2. 7L).

Disconnect BJB C1035A.

Measure:

2. 3L

Positive Lead	Measurement / Action	Negative Lead
C1035A-20	Courtesy of FORD MOTOR COMPANY	C175B-67

2. 7L

Positive Lead	Measurement / Action	Negative Lead
C1035A-20	Courtesy of FORD MOTOR COMPANY	C1551B-44

Is the resistance less than 3 ohms?

Yes

GO to L12

No	REPAIR the circuit.

L12 CHECK THE A/C (AIR CONDITIONING) COMPRESSOR CLUTCH FIELD COIL VOLTAGE SUPPLY CIRCUIT FOR AN OPEN

Disconnect A/C clutch field coil C100A.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1035A-10	Courtesy of FORD MOTOR COMPANY	C100A-1

Is the resistance less than 3 ohms?

Yes

GO to L13

No	REPAIR the circuit.

L13 CHECK THE A/C (AIR CONDITIONING) COMPRESSOR CLUTCH FIELD COIL GROUND CIRCUIT FOR AN OPEN

Measure:

Positive Lead	Measurement / Action	Negative Lead
C100A-2	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance less than 3 ohms?

Yes

GO to L14

No	REPAIR the circuit.

L14 CHECK FOR VOLTAGE TO THE A/C (AIR CONDITIONING) COMPRESSOR CLUTCH FIELD COIL

Connect PCMb C175B (2. 3L) or C1551B (2. 7L).

Connect BJB C1035A.

Ignition ON.

Access the PCM and control the ACC_CMDPID

Measure:

Positive Lead	Measurement / Action	Negative Lead
C100A-1	Courtesy of FORD MOTOR COMPANY	Ground

Is the voltage greater than 11 volts?

Yes

GO to L15

No	INSTALL a new BJB. REFER to: Body Control Module C (BCMC)

L15 CHECK THE A/C (AIR CONDITIONING) COMPRESSOR CLUTCH AIR GAP

Measure the A/C compressor clutch air gap at 3 equally spaced locations between the clutch hub and the A/C compressor clutch pulley. REFER to: Air Conditioning (A/C) Clutch Air Gap Adjustment

Is the A/C compressor clutch air gap greater than 0. 6 mm (0. 0236 in)?

Yes	ADJUST the A/C compressor clutch air gap as applicable. REFER to: Air Conditioning (A/C) Clutch Air Gap Adjustment

No	INSTALL a new A/C compressor clutch and field coil. REFER to: Air Conditioning (A/C) Clutch and Air Conditioning (A/C) Clutch Field Coil - 2. 3L EcoBoost (199kW/270PS) REFER to: Air Conditioning (A/C) Clutch and Air Conditioning (A/C) Clutch Field Coil - 2. 7L EcoBoost (238kW/324PS)

L16 CHECK FOR CORRECT HVAC (HEATING, VENTILATION AND AIR CONDITIONING) CONTROL MODULE OPERATION

Ignition OFF.

Disconnect and inspect all HVAC control module electrical connectors (if not previously disconnected).

Repair:
- corrosion (install new connector or terminal - clean module pins)
- damaged or bent pins - install new terminals or pins
- pushed-out pins - install new pins as necessary

Connect all HVAC control module electrical 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, INSTALL a new HVAC control module. REFER to: Heating, Ventilation and Air Conditioning (HVAC) Control Module

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.

L17 CHECK FOR AN INPUT DISABLING THE A/C (AIR CONDITIONING) CLUTCH RELAY

NOTE: The Powertrain Control Module (PCM) strategy may disable the Air Conditioning (A/C) compressor operation. If the A/C compressor clutch can be commanded on using a diagnostic scan tool Powertrain Control Module (PCM) Parameter Identifications (PIDs) Active Commands, Powertrain Control Module (PCM) replacement will not resolve the condition.

Diagnose the PCM not energizing the A/C clutch relay using the suggestions in the table below.

A/C Clutch Engagement is inhibited because strategy has not yet detected hardware that indicates vehicle is equipped with A/C
A/C Clutch Engagement is inhibited because the strategy is operating in Ignition System Failure Mode
A/C Clutch Engagement is inhibited because the (ECU) received a Request to Command the A/C Off
A/C Clutch Engagement is inhibited because the engine has not yet reached a stable running mode after starting
A/C Clutch Engagement is inhibited because the A/C Discharge (Head) Pressure is Too High
A/C Clutch Engagement is inhibited because the Engine Coolant Temperature is Too High
A/C Clutch Engagement is inhibited to Prevent Frost and Ice Build Up on the Evaporator
A/C Clutch Engagement is inhibited to Prevent an Engine Stall during a Low Engine Speed condition
A/C Clutch Engagement is inhibited to Protect the Compressor from a Compressor Over-speed condition
A/C Clutch Engagement is inhibited to temporarily make more power available when Accelerator Pedal is Fully Depressed
A/C Clutch Engagement is inhibited because Low A/C Refrigerant Charge has been detected
A/C Clutch Engagement is inhibited to Protect the Compressor from Operating at Too Low of an Ambient Temperature
A/C Clutch Engagement is inhibited due to Missing Climate Control Message
A/C Clutch Engagement is inhibited because the strategy is operating in Failsafe Cooling Mode
A/C Clutch Engagement is inhibited to Protect the Clutch from Damage because the Compressor Load and Speed are Too High
A/C Clutch Engagement is inhibited by the off portion of the A/C Cycling Strategy invoked to manage High Engine Temperature
A/C Clutch Engagement is inhibited due to Low Battery State of Charge
A/C Clutch Engagement is inhibited to Protect the Variable Displacement Compressor from Operating at Too Low of a Temperature
A/C Clutch Engagement is inhibited to improve Brake Booster Vacuum
A/C Clutch Engagement is inhibited because Evaporator Temperature is sufficiently low and compressor was at minimum displacement
A/C Clutch Engagement is inhibited (Disabled) because the Evaporator Temperature is sufficiently below the target temperature
A/C Clutch Engagement is inhibited to satisfy A/C Clutch minimum off time
A/C Clutch Engagement is inhibited Due to Request from Torque Control Strategy (to Temporarily Make More Power Available)
A/C Clutch Engagement is inhibited to Prevent Engine Stalling
A/C Clutch Engagement is inhibited Due to Request to Disable A/C from Stop-Start Strategy
A/C Clutch Engagement is inhibited (Delayed) to make Power Available for Power Steering
A/C Clutch Engagement Is Inhibited Due To State Of Auxiliary A/C Disable (Typically A Pressure Or Temperature) Switch 1 input
A/C Clutch Engagement is inhibited due to state of auxiliary A/C Disable (Typically a Pressure or Temperature) Switch 2 input

Are any of the conditions described above not within normal parameters?

Yes	DIAGNOSE the condition found to be disabling the A/C clutch relay. REFER to the appropriate Engine service information.

The A/C compressor clutch can be commanded on using the diagnostic scan tool PCM active command PID. The A/C inoperative concern may be caused by an intermittent condition due to a component or module connection, wiring or pin issue. ADDRESS the root cause of any connector or pin issues. CHECK the vehicle service history for recent service actions that have replaced modules. This condition may be due to incomplete or incorrect PMI procedures.