Condition Possible Causes Correction
2. Faulty fuse.2. Check the fuse in the junction block. Repair the
shorted circuit or component and replace the fuse,
if required.
3. Faulty A/C compressor
clutch field coil.3. See A/C Compressor Clutch Field Coil in this
group. Test the compressor clutch field coil and
replace, if required.
4. Improperly installed or
faulty Evaporator
Temperature Sensor.4. See Evaporator Temperature Sensor in this
group. Correctly install or replace the sensor as
required.
5. Faulty A/C pressure
transducer.5. See A/C pressure transducer in this group. Test
the transducer and replace, if required.
6. Faulty A/C-heater control,
totally integrated power
module (TIPM), gateway
module or PCM/ECM.6. Refer to the appropriate Electrical Diagnostic
Procedures for testing of the A/C-heater control,
TIPM, gateway module or PCM/ECM. Test the
module and replace, if required.
Normal pressures, but A/C
Performance Test air
temperatures at center panel
outlet are too high.1. Excessive refrigerant oil in
system.1. See Refrigerant Oil Level in this group. Recover
the refrigerant from the refrigerant system and
inspect the refrigerant oil content. Restore the
refrigerant oil to the proper level, if required.
2. Blend door inoperative or
sealing improperly.2. See Blend Door in this group. Inspect the blend
door for proper operation and sealing and correct,
if required.
3. Blend door actuator faulty
or inoperative.3. Perform blend door actuator diagnosis, replace
if faulty.
The low side pressure is
normal or slightly low, and
the high side pressure is too
low.1. Low refrigerant system
charge.1. See Refrigerant System Leaks in this group.
Test the refrigerant system for leaks. Repair,
evacuate and charge the refrigerant system, if
required.
2. Refrigerant flow through
the accumulator is restricted.2. See Accumulator in this group. Replace the
restricted accumulator, if required.
3. Refrigerant flow through
the evaporator coil is
restricted.3. See A/C Evaporator in this group. Replace the
restricted evaporator coil, if required.
4. Faulty compressor.4. See A/C Compressor in this group. Replace the
compressor, if required.
The low side pressure is
normal or slightly high, and
the high side pressure is too
high.1. Condenser air flow
restricted.1. Check the A/C condenser for damaged fins,
foreign objects obstructing air flow through the
condenser fins, and missing or improperly
installed air seals. Refer to Cooling for more
information on air seals. Clean, repair, or replace
components as required.
2. Inoperative cooling fan.2. Refer to Cooling for more information. Test the
cooling fan and replace, if required.
3. Refrigerant system
overcharged.3. See Refrigerant System Charge in this group.
Recover the refrigerant from the refrigerant
system. Charge the refrigerant system to the
proper level, if required.
4. Air in the refrigerant
system.4. See Refrigerant System Leaks in this group.
Test the refrigerant system for leaks. Repair,
evacuate and charge the refrigerant system, if
required.
Condition Possible Causes Correction
5. Engine overheating.5. Refer to Cooling for more information. Test the
cooling system and repair, if required.
The low side pressure is too
high, and the high side
pressure is too low.1. Accessory drive belt
slipping.1. Refer to Cooling for more information. Inspect
the accessory drive belt condition and tension.
Tighten or replace the accessory drive belt, if
required.
2. Fixed orifice tube not
installed.2. See A/C Orifice Tube in this group. Replace the
liquid line, if required.
3. Faulty A/C compressor.3. See A/C Compressor in this group. Replace the
compressor, if required.
The low side pressure is too
low, and the high side
pressure is too high.1. Restricted refrigerant flow
through the refrigerant lines.1. See Liquid, Suction, and Discharge Line in this
group. Inspect the refrigerant lines for kinks, tight
bends or improper routing. Correct the routing or
replace the refrigerant line, if required.
2. Restricted refrigerant flow
through the fixed orifice
tube.2. See A/C Orifice Tube in this group. Replace the
liquid line, if required.
3. Restricted refrigerant flow
through the condenser.3. See A/C Condenser in this group. Replace the
restricted condenser, if required.
HEATER PERFORMANCE
Before performing the following tests, refer to Group 7 - Cooling for the procedures to check the engine coolant
level and flow, engine coolant reserve/recovery system operation, accessory drive belt condition and tension, radi-
ator air flow and the fan drive operation. Perform the HVAC System Test (refer to 24 - HVAC Electrical Diagnostics).
If any diagnostic trouble codes (DTCs) are found in the A/C-heater control, powertrain control module (PCM) or
engine control module (ECM) (depending on engine application), gateway module or totally integrated power module
(TIPM), repair as necessary.
MAXIMUM HEATER OUTPUT: TEST AND ACTION
Engine coolant is provided to the heater system through two heater hoses. With the engine idling at normal oper-
ating temperature, set the temperature control to maximum heat position,the mode control to the floor position, and
the blower motor control to the highest speed position. Using a test thermometer, check the temperature of the air
being discharged from the floor outlets. Compare the test thermometer reading to the Heater Temperature Refer-
ence chart.
HEATER TEMPERATURE REFERENCE
Ambient Air Temperature16° C
(60° F)21° C
(70° F)26° C
(80° F)32° C
(90° F)
Minimum Air Temperature at
Floor Outlet62° C
(144° F)64° C
(147° F)65° C
(150° F)67° C
(153° F)
If the heater outlet air temperature is below the minimum specification, refer to Group 7 - Cooling. Both of the heater
hoses should be hot to the touch. The coolant return heater hose should be slightly cooler than the coolant supply
heater hose. If the return hose is much cooler than the supply hose, locate and repair the engine coolant flow
obstruction in the cooling system. RefertoGroup7-Coolingformoreinformation.
OBSTRUCTED COOLANT FLOW
Possible locations or causes of obstructed coolant flow are as follows:
Faulty water pump.
Faulty thermostat.
Pinched or kinked heater hoses.
The blend door actuators are diagnosed using a scan tool (Refer to 24 - HEATING & AIR CONDITIONING - DIAG-
NOSIS AND TESTING and to 24 - HVAC Electrical Diagnostics for more information).
The blend door actuators cannot be adjusted or repaired and, if faulty or damaged, they must be replaced.
REMOVAL
WARNING: On vehicles equipped with airbags, disable the airbag system before attempting any steering
wheel, steering column, or instrument panel component diagnosis or service. Disconnect and isolate the
battery negative (ground) cable, then wait two minutes for the airbag system capacitor to discharge before
performing further diagnosis or service. This is the only sure way to disable the airbag system. Failure to
take the proper precautions could result in accidental airbag deploymentand possible personal injury or
death.
NOTE: The single zone heating-A/C system is equipped with a single blend door actuator. The dual zone
system has two blend door actuators, one for the driver side blend-air doorand one for the passenger side
blend-air door.
SINGLE ZONE/DUAL ZONE DRIVER SIDE
1. Disconnect and isolate the negative battery cable.
2. Remove the instrument panel from the vehicle
(Refer to 23 - BODY/INSTRUMENT PANEL/IN-
STRUMENT PANEL ASSEMBLY - REMOVAL).
3. Remove the two screws (1) that secure the blend
door actuator (2) to the back of the HVAC housing
(3).
4. Remove the blend door actuator from the HVAC
housing and disconnect the HVAC wire harness
connector (4) from the actuator.
5. Remove the blend door actuator from the vehicle.
ACTUATOR-MODE DOOR
DESCRIPTION
The mode door actuators are reversible, 12-volt direct
current (DC) servo motors.The heating-A/C systems
on this vehicle use two mode door actuators. One for
the panel/floor-air door and one for the defrost-air
door.
Both the panel/floor door actuator (1) and the defrost
door actuator (2) are located on the driver side end of
the HVAC housing (3), close to the dash panel.
All actuators (1) are interchangeable with each other.
Each actuator is contained within an identical black
molded plastic housing with an integral wire connector
receptacle (2). Each actuator also has an identical
output shaft with splines (3) that connects it to its
respective door linkage and three integral mounting
tabs (4) that allow the actuator to be secured to the
HVAC housing. The mode door actuators do not
require mechanical indexing to the mode-air doors, as
they are electronically calibrated by the A/C-heater
control.
OPERATION
The mode door actuators are connectedto the A/C-heater control through the vehicle electrical system by dedicated
two-wire leads and connectors of the HVAC wire harness. The mode door actuators can move the defrost-air door
and the panel/floor-air door in two directions. When the A/C-heater control pulls the voltage on one side of the motor
connection high and the other connection low, the mode-air door will move in one direction. When the A/C-heater
control reverses the polarity of the voltage to the motor, the mode-air door moves in the opposite direction.
When the A/C-heater control makes the voltage to both connections high or both connections low, the mode-air door
stops and will not move. The A/C-heater control uses a pulse-count positioning system to monitor the operation and
relative position of the mode door actuators and the mode-air doors. The A/C-heater control learns the mode-air
door stop positions during the calibration procedure and will store a diagnostic trouble code (DTC) for any problems
it detects in the mode door actuator circuits.
The mode door actuators are diagnosed using using a scan tool (Refer to 24 - HEATING & AIR CONDITIONING -
DIAGNOSIS AND TESTING and to 24 - HVAC Electrical Diagnostics for more information).
ACTUATOR-RECIRCULATION DOOR
DESCRIPTION
The recirculation door actuator (1) is a reversible
12-volt direct current (DC)servo motor. The single
recirculation door actuator is located on the passenger
side end of the HVAC housing (2), on the top of the
air inlet housing.
All actuators (1) are interchangeable with each other.
Each actuator is contained within an identical black
molded plastic housing with an integral wire connector
receptacle (2). Each actuator also has an identical
output shaft with splines (3) that connects it to its
respective door linkage and three integral mounting
tabs (4) that allow the actuator to be secured to the
HVAC housing. The recirculation door actuator does
not require mechanical indexing to the recirculation-air
door, as it is electronically calibrated by the A/C-heater
control.
OPERATION
The recirculation door actuator is connected to the heater-A/C control module through the vehicle electrical system
by a dedicated two-wire lead and connector of the HVAC wire harness. The recirculation door actuator can move
the recirculation-air door in two directions. When the A/C-heater control pulls the voltage on one side of the motor
connection high and the other connection low, the recirculation-air doorwill move in one direction.
When the A/C-heater control makes the voltage to both connections high or both connections low, the recirculation-
air door stops and will not move. The A/C-heater control uses a pulse-countpositioning system to monitor the oper-
ation and relative position of the recirculation door actuator and the recirculation-air door. The A/C-heater control
learns the recirculation-air door stop positions during the calibrationprocedure and will store a diagnostic trouble
code (DTC) for any problems it detects in the recirculation door actuator circuits.
The recirculation door actuator is diagnosed using a scan tool (Refer to 24- HEATING & AIR CONDITIONING -
DIAGNOSIS AND TESTING and to 24 - HVAC Electrical Diagnostics for more information).
The recirculation door actuator cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.
CLUTCH-A/C COMPRESSOR
DESCRIPTION
NOTE: Denso 10S17 A/C clutch assembly shown.
Visteon HS-18 compressor similar.
The A/C compressor clutch assembly consists of a
stationary electromagnetic field coil (4), bearing and
pulley assembly (3), shims (7) and a clutch plate (2)
that is splined to the compressor shaft and secured by
a bolt (1). These components provide the means to
engage and disengage the A/C compressor from the
engine accessory drive belt.
The A/C clutch bearing and pulley assembly on both
A/C compressors are retained to the front of the com-
pressor with a snap ring (6). The A/C clutch field coil
on the Denso 10S17 A/C compressor is also retained
to the front of the compressor using a snap ring (5).
The field coil on the Visteon HS-!8 compressor is
pressed onto the front of the compressor.
OPERATION
The A/C compressor clutch components provide the means to engage and disengage the A/C compressor from the
engine accessory drive belt. When the electromagnetic A/C clutch field coil is energized, it magnetically draws the
clutch plate into contact with the clutch pulley and drives the compressorshaft. When the coil is not energized, the
pulley freewheels on the clutch hub bearing, which is part of the pulley assembly.
A/C compressor clutch engagement is controlled by the powertrain controlmodule (PCM) or the engine control mod-
ule (ECM), depending on engine application. When the A/C-heater control is set to any A/C position, it sends a
request signal on the CAN-B bus to the totally integrated power module (TIPM), which then transfers the request on
the CAN-C Bus to the PCM/ECM, which determines if operating conditions arecorrect for A/C clutch engagement.
When all operating conditions have been met, the PCM/ECM sends a signal on adedicated hard-wired circuit back
to the totally integrated power module (TIPM) to energize the internal A/Cclutch high side driver. When energized,
the A/C clutch high side driver provides battery current to the A/C clutch field coil.
The A/C clutch control system is diagnosed using a scan tool (Refer to 24 - HVAC Electrical Diagnostics and to 9
- Engine Electrical Diagnostics for more information).
The A/C compressor clutch components cannot be repaired and, if faulty or damaged, they must be replaced.
DIAGNOSIS AND TESTING
A/CCOMPRESSORCLUTCHCOIL
The A/C compressor clutch coil electrical circuit is controlled by the powertrain control module (PCM) or the engine
control module (ECM) (depending on engine application) through the totally integrated power module (TIPM) (Refer
to 24 - HEATING & AIR CONDITIONING/CONTROLS/COIL-A/C COMPRESSOR CLUTCH -OPERATION for more
information). Begin testing of a suspected compressor clutch coil problem by performing the preliminary checks.
PRELIMINARY CHECKS
1. Using a scan tool, check for diagnostic trouble codes (DTCs) in the A/C-heater control, TIPM, PCM/ECM and if
equipped with the 8.3L engine, the gateway module. If no DTCs are found, go to Step 2. If any DTCs are found,
repair as required.
2. If the A/C compressor clutch still will not engage, verify the refrigerant charge level (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - DIAGNOSIS AND TESTING - REFRIGERANT SYSTEM LEAKS). If the refrig-
erant charge level is OK, go to TESTS . If the refrigerant charge level is notOK, adjust the refrigerant charge as
required.
TESTS
1. Verify the battery state of charge (Refer to 8 - ELECTRICAL/BATTERY SYSTEM/BATTERY - DIAGNOSIS AND
TESTING).
2. Connect an ammeter (0 to 10 ampere scale selected) in series with the clutch coil feed terminal. Connect a
voltmeter (0 to 20 volt scale selected) to measure voltage across the battery and the clutch coil.
3. With the A/C-heater control in the A/C mode and the blower motor at low speed, start the engine and allow it to
run at a normal idle speed.
4. The A/C compressor clutch should engage immediately, and the clutch coil supply voltage should be within two
volts of the battery voltage. If the coil supply voltage is OK, go to Step 5. If the coil supply voltage is not within
two volts of battery voltage, test the clutch coil feed circuit for excessive voltage drop and repair as necessary.
5. For the acceptable A/C clutch coil current draw specifications refer to24 - HEATING & AIR CONDITIONING -
SPECIFICATIONS. Specifications apply for a work area temperature of 21° C(70° F). If voltage is more than
12.5 volts, add electrical loads by turning on electrical accessories until voltage reads below 12.5 volts.
STANDARD PROCEDURE
A/C CLUTCH PLATE INSPECTION
NOTE: The A/C clutch can be serviced inthe vehicle. The refrigerant systemcan remain fully-charged dur-
ing compressor clutch, pulley and bearing assembly, or coil replacement.
Examine the friction surfaces of the pulley and the
clutch plate (2) for wear. The pulley and clutch plate
should be replaced if there is excessive wear or scor-
ing.
If the friction surfaces are oily, inspect the shaft and
nose area of the A/C compressor (1) for refrigerant oil.
If refrigerant oil is found, the compressor shaft seal is
leaking and the A/C compressor must be replaced.
Check the pulley bearing for roughness or excessive
leakage of grease. Replace the pulley and bearing
assembly, if required.
A/C CLUTCH BREAK-IN
After a new A/C compressor clutch hasbeen installed, cycle the compressorclutch approximately 20 times (5 sec-
onds on, then 5 seconds off). During this procedure, set the A/C-heater controls to the A/C Recirculation Mode, the
blower motor in the highest speed position, and the engine speed at 1500 to 2000 rpm. This procedure (burnishing)
will seat the opposing friction surfaces and provide a higher compressor clutch torque capability.
1. Disconnect and isolate negative battery cable.
2. Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/BELTS-DRIVE -
REMOVAL).
3. Raise and support the vehicle.
4. Disconnect the engine wire harness from the clutch
field coil connector (4).
5. Remove the bolts that secure the A/C compressor
(5)tothemountingbracket(Referto24-HEAT-
ING & AIR CONDITIONING/PLUMBING/COM-
PRESSOR-A/C - REMOVAL).
6. Remove the A/C compressor from the mounting
bracket and support the compressor while servicing
the clutch.
7. Using compressor clutch holding fixture (Special
Tool 9351 in Kit 9349) (1), remove the bolt (2) that
secures the clutch plate (3) to the compressor
shaft.
NOTE: The clutch plate can be removed from the compressor shaft by hand or, if required, pressed off with
an 8 x 1.25 mm bolt.
NOTE: Clutch plate shim(s) may remain inside the hub of the clutch plate. Besure to remove all of the
shims from inside the hub or from the end of the compressor shaft.
8. Remove the clutch plate and shim(s) from the A/C compressor. If required, install a 8 x 1.25 mm bolt into the
centeroftheclutchplateandturntheboltclockwiseuntiltheclutchplate is completely removed from the A/C
compressor.
9. Using snap ring pliers (1), remove the snap ring (2)
that secures the pulley and bearing assembly (3) to
the front of the A/C compressor (4).