2003 FORD MUSTANG clutch

evaporator core, it absorbs heat from the passenger compartment airflow passing over the plate/fin
sections of the A/C evaporator core. This addition of heat causes the refrigerant to boil (convert to a
gas). The now cooler passenger compartment air can no longer support the same humidity level of the
warmer air and this excess moisture condenses on the exterior of the evaporator coils and fins and
drains outside the vehicle.
The suction accumulator/drier (19C836) is designed to remove moisture from the refrigerant and to
prevent any liquid refrigerant that may not have been vaporized in the A/C evaporator core from
reaching the A/C compressor. The A/C compressor is designed to pump refrigerant vapor only, as
liquid refrigerant will not compress and can damage the A/C compressor.
The refrigerant cycle is now repeated with the A/C compressor again increasing the pressure and
temperature of the refrigerant.
The A/C cycling switch (19E561) interrupts compressor operation before the external temperature of
the A/C evaporator core gets low enough to cause the condensed water vapor (excess humidity) to
turn to ice. It does this by monitoring low side line pressure. It is known that a refrigerant pressure of
approximately 210 kPa (30 psi) will yield an operating temperature of 0°C (32°F). The A/C cycling
switch controls system operation in an effort to maintain this temperature.
The high side line pressure is also monitored so that the A/C compressor operation can be interrupted
if system pressure becomes too high.
The A/C compressor pressure relief valve (19D644) will open and vent refrigerant to relieve unusually
high system pressure.
Clutch Cycling Orifice Tube Type Refrigerant System Klj . 4 ba
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2. Inspect to determine if one of the following mechanical or electrical concerns apply:
a A leak in the vacuum control circuit may occur during acceleration (slow leak), at all times
(large leak), or only when specific functions are selected (indicating a leak in that portion of the
circuit). The vacuum hoses used in the passenger compartment control circuit are constructed
from PVC plastic material. The vacuum hoses used in the engine compartment are constructed
of Hytrel® . Because of the materials used, never pinch the vacuum hoses off during diagnosis
to locate a leak. A wood golf tee can be used as a plug when it is necessary to plug one end of
a vacuum hose for leak test purposes.
3. If the inspection reveals obvious concerns that can be readily identified, repair as required.
4. If the concern remains after the inspection, connect the scan tool to the data link connector (DLC) located beneath the instrument panel and select the vehicle to be tested from the scan
tool menu. If the vehicle selection cannot be entered:
zcheck that the program card is correctly installed.
z check the connections to the vehicle.
z check the ignition switch position.
If the scan tool still does not allow the vehicle selection to be entered, refer to the scan tool manual. 5. Carry out the DATA LINK DIAGNOSTIC TEST using the scan tool. If the scan tool responds with:
zCKT 914, CKT 915 or CKT 70 = ALL MODULE NO RESPONSE/NOT EQUIPPED, go to
Communication System Diagnostics in Section 418 - 00 to diagnose network concern.
z If the powertrain control module (PCM) is not listed for a communication concern, turn
the A/C function selector switch to OFF and execute self- test diagnostics for the PCM.
6. If any PCM DTCs are retrieved, and are related to the concern, go to the Powertrain Control Module Diagnostic Trouble Code (DTC) Index to continue diagnostics.
7. If no DTCs related to the concern are retrieved, go to the Symptom Chart to continue diagnostics.
Symptom Chart Visual Inspection Chart Mechanical Electrical
z
Loose, missing or damaged A/C compressor
drive belt.
z Loose or disconnected A/C clutch.
z Loose, misrouted or damaged vacuum lines. a
z Broken or leaking refrigerant lines.
z Broken or leaking vacuum control motor. z
Open fuses.
z Blower motor inoperative.
z A/C compressor inoperative.
z Circuitry open/shorted.
z Disconnected electrical
connectors.
Powertrain Control Module Diagnostic Trouble Code (DTC) Index DTC Description Action
P1460 WOT A/C cutout circuit
malfunction Refer to the Powertrain Control/Emissions Diagnosis
(PC/ED) manual.
P1464 A/C demand out of self-
test
range GO to DTC P1464. Klj . 5 ba
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Symptom Chart
Condition
Possible Sources Action
z Incorrect/erratic direction
of airflow from outlet(s) z
No vacuum to A/C heater
function switch selector.
z A/C heater function selector
switch leaks vacuum.
z Kinked/pinched vacuum hose.
z Leaking vacuum control
motor.
z Leaking A/C vacuum check
valve.
z Leaking A/C vacuum reservoir
tank and bracket.
z Vacuum actuator arm not
connected to door crank. z
Go To Pinpoint
Test A .
z Insufficient, erratic, or no
heat z
Low engine coolant level.
z Thermostat stuck open.
z Disengaged/damaged
temperature cable. z
Go To Pinpoint
Test B .
z The A/C does not
operate/does not operate
correctly z
CASS strategy failure.
z Open fuses.
z A/C clutch relay.
z Shorted blend door actuator.
z Powertrain control module.
z Circuitry short/open.
z A/C cycling switch damaged.
z A/C system discharged/low
charge.
z Function selector switch
damaged.
z A/C pressure cut-off switch
damaged.
z A/C compressor clutch
damaged. z
Go To Pinpoint
Test C .
z The A/C is always on zCircuitry short/open.
z A/C cycling switch.
z A/C heater function selector
switch.
z Constant control relay
module.
z Incorrect A/C clutch air gap. z
Go To Pinpoint
Test D .
z Insufficient A/C cooling zRestricted A/C evaporator
core orifice.
z Low refrigerant level. z
Go To Pinpoint
Test E .
z No operation in all the
temperature settings z
Damaged blend door actuator
cable.
z Damaged air temperature
control door. z
Go To Pinpoint
Test F .
z The blower motor does
not operate z
Open fuse.
z Circuitry open/shorted.
z Damaged heater blower
motor switch (18578).
z Damaged heater blower
motor switch resistor (18591).
z Damaged blower motor relay.
z Damaged blower motor. z
Go To Pinpoint
Test G .
z The blower motor
operates continuously in z
Circuitry short/open.
z Damaged heater blower z
Go To Pinpoint Klj . 6 ba
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z
Disconnect: CCRM C1262.
z Measure the resistance of CCRM C1262- 18, circuit 1205
(BK), harness side and ground.
z Is the resistance reading less than 5 ohms? GO to
C21 .
No
REPAIR circuit 1205 (BK) for
an open. TEST the system for
normal operation. C21 CHECK CIRCUIT 20 (WH/LB) AT THE CONSTANT
CONTROL RELAY MODULE z
Key in ON position.
z Measure the voltage at the CCRM C1262- 13, circuit 20
(WH/LB), harness side and ground.
z Is the voltage reading greater than 10 volts? Yes
GO to
C22 .
No
REPAIR circuit 20 (WH/LB) for
an open. TEST the system for
normal operation. C22 CHECK THE POWER TO THE A/C CLUTCH
z
Key in OFF position.
z Connect: CCRM 1262.
z Disconnect: A/C Clutch C100.
z Turn the function selector to the A/C position.
z Measure the voltage at the A/C clutch C100, circuit 347
(BK/YE), harness side and ground. Yes
GO to
C24 .
No
GO to C23 . Klj . 22 ba
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z
Is the voltage greater than 10 volts? C23 CHECK CIRCUIT 331 (PK/YE) FOR AN OPEN.
z
Key in OFF position.
z Disconnect: CCRM C1262.
z Key in ON position.
z Enter the following diagnostic mode on the diagnostic
tool:
z In the Active Command Mode command the PCM
outputs ON.
z Measure the resistance between the CCRM C1262- 22,
circuit 331 (PK/YE), harness side and ground.
z Is the resistance reading less than 5 ohms? Yes
GO to
C24 .
No
REPAIR circuit 331 (PK/YE) for
an open. TEST the system for
normal operation. C24 CHECK CIRCUIT 347 (BK/YE)
z
Key in OFF position.
z Measure the resistance between CCRM C1262- 23,
circuit 347 (BK/YE), harness side and A/C clutch C100-
1, harness side.
z Is the resistance less than 5 ohms? Yes
GO to
C25 .
No
REPAIR circuit 347 (BK/YE) for
an open. TEST the system for
normal operation. C25 CHECK CIRCUIT 347 (BK/YE) FOR A SHORT TO
GROUND. z
Measure the resistance between A/C clutch C100- 2,
circuit 1205 (BK), harness side and the CCRM C1262-
16, circuit 1205 (BK) harness side. Yes
INSTALL a new constant
control relay module. TEST the
system for normal operation. Klj . 23 ba
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PINPOINT TEST E: INSUFFICIENT A/C COOLING C294c-
3, circuit 348 (PK), harness side and ground.
z Is there voltage present? No
INSTALL a new function
selector switch. REFER to
Section 412
- 04 . TEST the
system for normal operation. D5 CHECK FOR A SHORTED CLUTCH INPUT
z
Key in OFF position.
z Disconnect: A/C Clutch C100.
z Key in ON position.
z Measure for voltage at the A/C clutch C100, circuit 347
(BK/YE), harness side and ground.
z Is there voltage present? Yes
INSTALL a new constant
control relay module. TEST the
system for normal operation.
No
CHECK the clutch air gap.
REFER to
Air Conditioning (A/C) Clutch Air Gap
Adjustment .
Test Step Result / Action to Take
E1 CHECK THE CENTER A/C REGISTER DISCHARGE
TEMPERATURE z
Carry out the refrigerant system tests. Refer to
Refrigerant System Tests in this section.
z Use the recorded data from the refrigerant system tests
to plot a vertical line for ambient temperature and a
horizontal line for center A/C register discharge
temperature.
z Is the intersection of the two lines within the upper
and lower limits? Yes
The tests indicate that the
system is functioning normally.
No
GO to
E2 . Klj . 25 ba
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E2 CHECK FOR NORMAL DISCHARGE PRESSURE
z
Use the recorded data from the refrigerant system tests
to plot a vertical line for ambient temperature and a
horizontal line for compressor discharge (high) pressure.
z Is the intersection of the two lines within the upper
and lower limits? Yes
GO to
E3 .
No
GO to E8 .
E3 EVALUATE THE SYSTEM LOW PRESSURE
PERFORMANCE z
Use the recorded data from the refrigerant system tests
to plot a vertical line for ambient temperature and a
horizontal line for compressor suction (low) pressure.
z Is the intersection of the two lines within the upper
and lower limits? Yes
GO to
E4 .
No
GO to E6 .
E4 CHECK FOR A SLOW OR CONTINUOUS RUN A/C
CLUTCH CYCLE RATE z
Use the recorded data from the refrigerant system tests
to plot a vertical line for ambient temperature and a
horizontal line for total A/C clutch cycle time (time ON
plus time OFF) in seconds.
z Is the intersection of the two lines above the upper
limit? Yes
GO to
E5 .
No
INSTALL a new A/C
evaporator core due to a
partially restricted or plugged
condition. REFER to Section 412 - 02 . TEST the system for
normal operation. E5 CHECK FOR A LONG OR CONTINUOUS A/C CLUTCH
OFF TIME z
Use the recorded data from the refrigerant system tests Yes Klj . 26 ba
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to plot a vertical line for ambient temperature and a
horizontal line for A/C clutch OFF time in seconds.
z Is the intersection of the two lines above the upper
limit? DISCHARGE and RECOVER
the system to remove
excessive moisture or
refrigerant oil. REFER to
Air Conditioning (A/C) System
Recovery, Evacuation and
Charging . TEST the system
for normal operation.
No
GO to E7 .
E6 CHECK FOR A HIGH SUCTION PRESSURE
z
Refer to the data plot used to evaluate the system low
pressure performance in Step E3.
z Is the intersection of the two lines above the upper
limit? Yes
REMOVE the A/C evaporator
core orifice to repair missing or
damaged (leaking) O-
ring
seals. REFER to Section 412 -
03 . TEST the system for
normal operation.
No
INSTALL a new A/C cycling
switch when the intersection of
the two lines is below the
lower limit. REFER to Section 412 - 03 . TEST the system for
normal operation. E7 CHECK THE AMBIENT TEMPERATURE
z
Refer to the data plot used to evaluate the system A/C
clutch OFF time in Step E5.
z Is the ambient temperature above 26°C (80°F)? Yes
This is normal operation for
the refrigerant system in high
humidity conditions.
No
DISCHARGE and RECOVER
the system to correct an
overcharge condition. REFER
to
Air Conditioning (A/C) System Recovery, Evacuation
and Charging . TEST the
system for normal operation. E8 CHECK FOR A HIGH DISCHARGE PRESSURE
z
Refer to the data plot used to evaluate the system high
pressure performance in Step E2.
z Is the intersection of the two lines above the upper
limit? Yes
GO to
E9 .
No
GO to E11 .
E9 CHECK FOR A NORMAL LOW PRESSURE
z
Use the recorded data from the refrigerant system tests
to plot a vertical line for ambient temperature and a
horizontal line for compressor suction (low) pressure. Yes
REFER to
Section 303 - 03A or
Section 303 - 03B . to diagnose
the engine cooling system.
TEST the system for normal
operation. Klj . 27 ba
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