2003 FORD MUSTANG vacuum

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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PINPOINT TEST A: INCORRECT/ERRATIC DIRECTION OF AIRFLOW
FROM OUTLET z
Is there voltage present? Test Step Result / Action to
Take A1 CHECK AIRFLOW FROM DEFROSTER OUTLETS
z
Key in START position.
z Place the heater blower motor switch in the HI position and
rotate the function selector switch to each position.
z Check for correct airflow from each function selector switch
position at engine idle and during engine speed acceleration.
z Is there airflow from defroster outlets under all conditions? Yes
GO to
A2 .
No
If the airflow is from
defroster outlets in all
switch positions only
under engine speed
acceleration, GO to
A19 .
If the airflow is
incorrect under one or
more conditions, GO to
A13 .
If the airflow is correct
under all conditions,
RETURN to the
Symptom Chart. A2 CHECK THE VACUUM SUPPLY HOSE
z
Key in OFF position.
z Verify the vacuum supply hose is connected between the engine
manifold and the A/C vacuum check valve.
z Is the hose connected? Yes
GO to
A3 .
No
RECONNECT the
hose. TEST the system
for normal operation. A3 LEAK CHECK THE VACUUM SUPPLY HOSE Klj . 8 ba
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z
Disconnect: Vacuum Supply Hose.
z Connect one end of the vacuum supply hose to a vacuum pump
and test for leaks.
z Does the hose leak? Yes
REPAIR or INSTALL a
new vacuum hose.
TEST the system for
normal operation.
No
GO to
A4 .
A4 CHECK THE VACUUM CHECK VALVE
z
Key in START position.
z Check the A/C vacuum check valve for correct installation by
removing (one at a time) the reservoir hose and the control
assembly source hose from the A/C vacuum check valve. Check
for vacuum.
z Is vacuum available at both check valve ports? Yes
GO to
A6 .
No
GO to A5 .
A5 INSPECT THE VACUUM CHECK VALVE
z
Key in OFF position.
z Disconnect: A/C Vacuum Check Valve.
z Inspect the A/C vacuum check valve for an obstruction and
correct operation. Airflow through the A/C vacuum check valve
should be in the direction toward the engine (engine connection
site is marked "VAC").
z Is the A/C vacuum check valve plugged or obstructed? Yes
INSTALL a new A/C
vacuum check valve.
TEST the system for
normal operation.
No
GO to
A6 .
A6 LEAK TEST THE VACUUM CHECK VALVE
z
Key in OFF position.
z Disconnect: Vacuum Check Valve.
z Connect the A/C vacuum check valve to a vacuum pump with
two hoses and a tee fitting. Yes
INSTALL a new A/C
vacuum check valve.
TEST the system for
normal operation.
No
RECONNECT the A/C
vacuum check valve.
GO to
A7 . Klj . 9 ba
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z
Pump 51 kPa (15 in- Hg) vacuum on the A/C vacuum check valve
and observe the gauge reading.
z If the vacuum loss exceeds 3.37 kPa (1 in- Hg) per minute,
remove the A/C vacuum check valve from the tester and plug the
vacuum hoses. Pump 51 kPa (15 in- Hg) of vacuum with the
tester to be certain the hoses and tester are not the cause of the
leak.
z Does the A/C vacuum check valve lose more than 3.37 kPa
(1 in- Hg) of vacuum in one minute? A7 CHECK THE VACUUM RESERVOIR
z
Disconnect: A/C Vacuum Reservoir Tank.
z Use a vacuum pump to leak test the A/C vacuum reservoir tank.
z Does the reservoir leak? Yes
INSTALL a new A/C
vacuum reservoir tank.
TEST the system for
normal operation.
No
RECONNECT the A/C
vacuum reservoir tank.
GO to
A8 .
A8 CHECK THE SUPPLY HOSE
z
Disconnect: Function Selector Switch Supply Hose.
z Use a vacuum pump to leak test the function selector switch
supply hose.
z Does the function selector switch supply hose leak? Yes
REPAIR or INSTALL a
new function selector
switch supply hose.
TEST the system for
normal operation.
No
RECONNECT the
function selector switch
supply hose. GO to
A9
.
A9 CHECK THE CONTROL ASSEMBLY
z
Disconnect: In- line Vacuum Harness.
z Connect a vacuum pump to the black hose and plug the other
hoses. Yes
NOTE the function
selector switch position
where the vacuum
drops. GO to
A10 . Klj . 10 ba
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z
At each function selector switch position, apply 51 kPa (15 in- Hg)
of vacuum and check for vacuum drop.
z Does the vacuum drop exceed 3.37 kPa (1 in- Hg) per
minute? No
RECONNECT the in-
line vacuum harness
connector. GO to
A11 .
A10 LEAK TEST THE CONTROL ASSEMBLY
z
Disconnect: Function Selector Switch Vacuum.
z Connect a vacuum pump to the function selector switch supply
port and plug the control port that indicated a leak in Step A9.
z Select the function selector switch position that indicated a leak
in Step A9 and then apply 51 kPa (15 in- Hg) of vacuum.
z Does the vacuum drop exceed 1.68 kPa (0.5 in- Hg) per
minute? Yes
INSTALL a new
function selector
switch. TEST the
system for normal
operation.
No
RECONNECT the
function selector switch
vacuum connector. GO
to
A12 .
A11 CHECK THE SUPPLY HOSE FOR OBSTRUCTIONS
z
Disconnect: Mode Selector Switch Supply Hose.
z Connect a vacuum pump to the supply hose and try to pull a
vacuum. If the vacuum pump can pull a vacuum, the hose is
plugged. If the vacuum pump pulls a partial vacuum, the hose is
restricted.
z Is the hose plugged or restricted? Yes
INSTALL a new supply
hose. TEST the system
for normal operation.
No
RECONNECT the A/C
damper door switch
supply hose. GO to
A15
.
A12 LEAK TEST THE JUMPER VACUUM HARNESS
z
Disconnect:
z Disconnect the suspect hose.
z Plug one end of the suspect hose and attach a vacuum pump to
the other end. Apply 51 kPa (15 in- Hg) of vacuum to the hose. Yes
REPAIR or INSTALL a
new vacuum jumper
harness. TEST the Klj . 11 ba
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z
Does the vacuum drop? system for normal
operation.
No
REPAIR or INSTALL a
new function selector
switch. TEST the
system for normal
operation.
A13 REVIEW THE VEHICLE'S HISTORY
z
Key in OFF position.
z Review the vehicles history.
z Did the climate control system function correctly prior to
this concern? Yes
GO to
A16 .
No
GO to A14 .
A14 CHECK THE VACUUM HOSES TO DAMPER DOORS
z
Connect a vacuum pump to each hose and try to pull a vacuum.
If the vacuum pump can pull a vacuum, the hose is plugged. If
the vacuum pump pulls a partial vacuum, the hose is restricted.
z Is a hose plugged or restricted? Yes
INSTALL a new
vacuum hose. TEST
the system for normal
operation.
No
GO to
A15 .
A15 CHECK THE VACUUM HARNESS
z
Compare the vacuum hose color in each vacuum harness to the
vacuum diagram.
z Does the hose color agree with the schematics? Yes
GO to
A16 .
No
INSTALL a new
vacuum harness. TEST
the system for normal
operation. A16 CHECK A/C VACUUM CIRCUIT
z
Check the A/C vacuum circuit for pinched or kinked vacuum
hose. Yes
REPAIR or INSTALL a
new vacuum hose.
TEST the system for
normal operation.
No
GO to
A17 . Klj . 12 ba
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z
Is the hose pinched or kinked? A17 CHECK VACUUM CIRCUIT CONNECTIONS
z
Check each vacuum hose connection to determine if it is partially
connected or disconnected.
z Is a vacuum hose disconnected or partially connected? Yes
RECONNECT the
hose. TEST the system
for normal operation.
No
GO to
A18 .
A18 CHECK THE VACUUM HOSE
z
Disconnect the suspect hose.
z Plug one end of the hose and attach a vacuum pump to the other
end. Check for a leak in the hose.
z Does the vacuum hose leak? Yes
REPAIR or INSTALL a
new hose. TEST the
system for normal
operation.
No
GO to
A19 .
A19 CHECK THE VACUUM CONTROL MOTOR
z
Disconnect: Vacuum Control Motor.
z Check the vacuum control motor for leaks with a vacuum pump. Yes
GO to
A20 .
No
INSTALL a new
vacuum control motor.
TEST the system for
normal operation. Klj . 13 ba
412003 Mustang Workshop Manual
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