Pinpoint Test G: The Air Conditioning (A/C) 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°C (32.0°F).
- Evaporator temperature is above approximately 1°C (33.8°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
- HVAC control module
Visual Inspection and Pre-checks
- Inspect for loose or corroded PCM and A/C clutch relay connection
- Verify BJB fuses 22 (10A) and 10 (7.5A) are OK.
- 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.

G1 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 the appropriate Refrigerant System Tests General Procedure in GENERAL PROCEDURES .

GO to G2

G2 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. REFER to: Reset the Outside Air Temperature Sensor Learned Values .

Does the A/C compressor turn on?

Yes	TEST the A/C system for normal operation. CARRY OUT the refrigerant system tests. REFER to the appropriate Refrigerant System Tests General Procedure in GENERAL PROCEDURES .

GO to G3

G3 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.

With the 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 G4

No	CHECK the A/C system for leaks. REFER to the appropriate Leak Detection General Procedures in GENERAL PROCEDURES . After the leak is repaired, RECHARGE the A/C system. REFER to the appropriate General Procedure in GENERAL PROCEDURES .

G4 CHECK THE COMMUNICATION NETWORK

Ignition ON.

Using a diagnostic scan tool, carry out the network test.

Do the HVAC control module and the PCM pass the network test?

Yes

GO to G5

No	DIAGNOSE the HVAC control module or PCM does not communicate with the diagnostic scan tool. REFER to: Communications Network .

G5 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°C (70°F). As ambient temperatures near 38°C (100.4°F), the pressure value difference increases above +/- 15 psi (103 kPa) range.
- Ignition ON.
- Using a diagnostic scan tool, view PCM Parameter Identifications (PIDs).
- With the manifold gauge set connected, compare the pressure readings of the manifold gauge set and the ACP_PRESS 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 G6

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

G6 ELECTRIC COOLING FAN FUNCTIONAL CHECK
- Ignition ON.
- Using a diagnostic scan tool, carry out the PCMKOEO self-test.
Does the electric cooling fan operate sometime during the KOEO self-test?

Yes GO to G7

No DIAGNOSE the electric cooling fan operation. REFER to COOLING FAN CONTROL .

G7 COMPARE THE PCM (POWERTRAIN CONTROL MODULE) INTAKE AIR TEMPERATURE (IAT) PID (PARAMETER IDENTIFICATION) 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 PCM to disable the A/C with or without a DTC.

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

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

Monitor the AAT, CACT, CHT, ECT, IAT, IAT2, MAF, MAPT, TCB and TCIPT Parameter Identifications (PIDs) (as applicable).

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

Yes

GO to G8

No	DIAGNOSE the suspect temperature sensor. REFER to INSTRUMENTATION, MESSAGE CENTER AND WARNING CHIMES for Ambient Air Temperature (AAT) sensor or Outside Air Temperature Display concerns. For all other temperature sensor concerns, REFER to the appropriate Engine article .

G8 COMPARE THE HVAC (HEATING, VENTILATION AND AIR CONDITIONING) CONTROL MODULE (A/C) EVAPORATOR TEMPERATURE (EVAP_TEMP) PID (PARAMETER IDENTIFICATION) TO THE PCM (POWERTRAIN CONTROL MODULE) AMBIENT AIR TEMPERATURE (AAT) PARAMETER IDENTIFICATION (PID)

Ignition OFF.

Allow the vehicle exterior and interior to stabilize to the outside ambient temperature.

Ignition ON.

Using a diagnostic scan tool, view the PCM Parameter Identification (PIDs).

Monitor and record the PCMPID AAT.

Using a diagnostic scan tool, view the HVAC control module Parameter Identification (PIDs).

Monitor and record the HVAC control module PID EVAP_TEMP.

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

Yes	If equipped with the active grille shutter system, GO to G9 If not equipped with the active grille shutter system, GO to G10

No	DIAGNOSE the evaporator temperature sensor. GO to Pinpoint Test L

G9 VERIFY THE GRILLE SHUTTER OPERATION USING THE PCM (POWERTRAIN CONTROL MODULE) GRILL SHUTTER A POSITION - COMMANDED (GRILL_A_CMD) PARAMETER IDENTIFICATION (PID)
- Start the engine and allow it to idle for at least 30 seconds to allow for the grille shutter calibration to complete.
- Using a diagnostic scan tool, view PCMPID.
- Using a diagnostic scan tool, select the PCMPID GRILL_A_CMD and command the grille shutter from 100% (open) to 0% (closed) while observing the grille shutter operation from the front of the vehicle.
Does the grill shutter fully open and close when commanded by the scan tool?

Yes GO to G10

No DIAGNOSE the active grille shutter is inoperative or does not operate correctly. REFER to: Active Grille Shutter .

G10 CHECK THE HVAC (HEATING, VENTILATION AND AIR CONDITIONING) CONTROL MODULE (A/C) SWITCH STATUS (CC_SW_AC) PID (PARAMETER IDENTIFICATION) WITH THE A/C (AIR CONDITIONING) ON
- Using a diagnostic scan tool, monitor the HVAC control module CC_SW_AC PID.
- Monitor the CC_SW_AC PID.
- On the HVAC controls, select PANEL and then press the A/C button (indicator ON).
Does the PID display Active or On when pressed and Inactive or Off when released?

Yes GO to G11

No GO to G18

G11 CHECK THE PCM (POWERTRAIN CONTROL MODULE) A/C (AIR CONDITIONING) REQUEST SIGNAL (AC_REQ) PID (PARAMETER IDENTIFICATION) WITH THE A/C (AIR CONDITIONING) ON
- Start the engine.
- Using a diagnostic scan tool, monitor the PCM AC_REQ PID.
- 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 G12

No GO to G18

G12 CHECK THE PCM (POWERTRAIN CONTROL MODULE) A/C (AIR CONDITIONING) COMPRESSOR COMMANDED STATE (ACC_CMD) PID (PARAMETER IDENTIFICATION) WITH THE A/C (AIR CONDITIONING) COMMANDED ON
- Using a diagnostic scan tool, activate the PCM ACC_CMD PID.
Does the A/C compressor turn on?

Yes GO to G19

No GO to G13

G13 CHECK THE A/C (AIR CONDITIONING) COMPRESSOR CLUTCH FIELD COIL GROUND CIRCUIT FOR AN OPEN

Ignition OFF.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C100-2	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance less than 3 ohms?

Yes

GO to G14

No	REPAIR the circuit.

G14 CHECK THE VOLTAGE TO THE A/C (AIR CONDITIONING) CLUTCH RELAY

Disconnect Air Conditioning (A/C) clutch relay.

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
A/C clutch relay socket 1 (component side)	Courtesy of FORD MOTOR COMPANY	Ground
A/C clutch relay socket 3 (component side)	Courtesy of FORD MOTOR COMPANY	Ground

Are the voltages greater than 11 volts?

Yes

GO to G15

No	VERIFY BJB fuse 22 (10A or 5A) and 10 (7.5A) are OK.If OK, REPAIR the circuit.If not OK, REFER to the OEM ELECTRICAL WIRING DIAGRAM INTRODUCTION to identify the possible causes of the circuit short.

G15 BYPASS THE A/C (AIR CONDITIONING) CLUTCH RELAY

Ignition OFF.

Connect a fused jumper wire:

Positive Lead	Measurement / Action	Negative Lead
A/C clutch relay socket 3 (component side)	Courtesy of FORD MOTOR COMPANY	A/C clutch relay socket 5 (component side)

Does the A/C compressor clutch engage?

Yes	REMOVE the fused jumper wire. INSTALL a new A/C clutch relay.

No	LEAVE the fused jumper wire installed. GO to G16

G16 CHECK THE A/C (AIR CONDITIONING) COMPRESSOR CLUTCH FIELD COIL VOLTAGE SUPPLY CIRCUIT FOR AN OPEN

Disconnect Air Conditioning (A/C) compressor clutch field coil C100 .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C100-1	Courtesy of FORD MOTOR COMPANY	Ground

Is the voltage greater than 11 volts?

Yes	REMOVE the fused jumper wire. GO to G17

No	REMOVE the fused jumper wire.REPAIR the circuit.

G17 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 (0.024 in)?

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

No	INSTALL a new A/C clutch and A/C clutch field coil. REFER to: Air Conditioning (A/C) Clutch and Air Conditioning (A/C) Clutch Field Coil .

G18 CHECK FOR CORRECT HVAC (HEATING, VENTILATION AND AIR CONDITIONING) CONTROL MODULE OPERATION

Ignition OFF.

Disconnect and inspect all HVAC control module electrical connectors.

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 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 module connections. ADDRESS the root cause of any connector or pin issues.

G19 CHECK FOR AN INPUT DISABLING THE A/C (AIR CONDITIONING) CLUTCH RELAY

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

NOTE: On some engines, Powertrain Control Module (PCM) AC_INHIBIT Parameter Identifications (PIDs) can be used to diagnose why the A/C clutch is not energizing. If AC_INHIBIT PIDS are Not available, follow the information below .

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 article .

The A/C compressor clutch can be commanded on using a diagnostic scan tool PCM Active command PID. The A/C inoperative concern may be caused by an intermittent condition do 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.