2003 FORD MUSTANG check engine

PINPOINT TEST B: THE SET SPEED FLUCTUATES z
Is the resistance less than 5 ohms? A16 CHECK CIRCUIT 239 (WH/OG) FOR AN OPEN
z
Disconnect: PCM C175.
z Connect EEC- V 104-Pin Breakout Box.
z Measure the resistance between speed control servo C122 pin
3, circuit 239 (WH/OG), harness side and Breakout Box, EEC- V
Control System pin 68, circuit 239 (WH/OG), harness side.
z Is the resistance less than 5 ohms? Yes
GO to
A17 .
No
REPAIR the circuit.
TEST the system for
normal operation. A17 CHECK THE SPEED CONTROL SERVO
z
INSTALL a known good speed control servo.
z Test drive the vehicle for correct operation.
z Does the speed control operate correctly? Yes
INSTALL a new speed
control servo; REFER to
Actuator
— Speed
Control Servo . TEST
the system for normal
operation.
No
INSTALL a new PCM;
REFER to Section 303 -
14 . TEST the system
for normal operation. Test Step Result / Action to Take
B1 CHECK THAT CONDITION OCCURS
ONLY WHILE USING SPEED CONTROL z
Check that the condition does not occur
when driving without speed control.
z Does the condition occur without
speed control? Yes
REPAIR engine as necessary. TEST the
system for normal operation.
No
GO to
B2 . Klj . 9 ba
132003 Mustang Workshop Manual
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Item Part Number Description
1 18A318 Vacuum control motor, panel/defrost door
2 18A478 Panel/defrost door (full vacuum position)
3 — Defrost airflow
4 — Side window demister airflow
5 18B545 Temperature blend door (full heat position)
6 19860 A/C evaporator core
7 19A813 Air inlet door (full vacuum position)
8 — Outside air inlet
9 18A318 Vacuum control motor—
air inlet door 10 — Recirculated air inlet
11 19805 Blower motor
12 — Vacuum from the engine intake manifold
13 19A563 A/C vacuum check valve
14 19A566 A/C vacuum reservoir tank and bracket
15 19B888 A/C-
heater function selector switch Klj . 3 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
412003 Mustang Workshop Manual
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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
412003 Mustang Workshop Manual
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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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PINPOINT TEST B: INSUFFICIENT, ERRATIC, OR NO HEAT z
Does the vacuum control motor hold a vacuum? A20 CHECK THE VACUUM CONTROL MOTOR INSTALLATION
z
Key in OFF position.
z Check the attachment of the vacuum control motor arm to
damper door.
z Is the vacuum control motor arm attached to the door or
door crank arm? Yes
REPAIR or INSTALL a
new damper door.
TEST the system for
normal operation.
No
CONNECT the vacuum
control motor arm to
the door and check
operation. TEST the
system for normal
operation.
Test Step Result / Action to Take
B1 CHECK FOR CORRECT ENGINE COOLANT LEVEL
z
Key in OFF position.
z Check the engine coolant level when hot and cold.
z Is the engine coolant at the correct level (hot/cold) as
indicated on the engine coolant recovery reservoir? Yes
GO to
B2 .
No
GO to B3 .
B2 CHECK FOR HOT WATER TO THE HEATER CORE INLET
HOSE WARNING: The heater core inlet hose will become
too hot to handle and may cause serious burns if the
system is working correctly.
z Key in START position.
z Allow the engine to reach normal operating temperature.
z Feel the heater core inlet hose. Yes
GO to
B4 .
No
TEST the engine cooling
system for correct
operation. REFER to
Section 303 - 03A or
Section 303 - 03B . Klj . 14 ba
412003 Mustang Workshop Manual
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PINPOINT TEST C: THE A/C DOES NOT OPERATE/DOES NOT
OPERATE CORRECTLY z
Is the heater core inlet hose too hot to handle? B3 CHECK THE ENGINE COOLING SYSTEM INCLUDING
RADIATOR CAP FOR LEAKS z
Fill the engine cooling system to specified level.
z NOTE: It is not necessary to check the components
separately at this time.
z Pressure check the engine cooling system. Refer to Section 303 - 03A or
Section 303 - 03B .
z Does the engine cooling system, including the radiator
cap, hold pressure? Yes
GO to
B4 .
No
Pressure test the heater
core. REFER to
Component Tests, Heater
Core — Pressure Test. B4 CHECK THE HEATER CORE OUTLET HOSE FOR HOT
WATER z
Feel the heater core outlet hose.
z Is the heater core outlet hose cool or cold? Yes
TEST the heater core for a
plugged or partially
plugged condition. REFER
to
Section 303 - 03A or
Section 303 - 03B .
No
GO to Pinpoint Test E .
Test Step Result / Action to Take
C1 CHECK THE PCM PID WACF
z
Connect the diagnostic tool.
z Turn the function selector to the OFF position.
z Key in ON position.
z Enter the following diagnostic mode on the diagnostic
tool:
z Monitor the PCM PID WACF while turning the function
selector.
z Does the PCM PID WACF read YES? Yes
REFER to the Powertrain
Control/Emissions Diagnosis
(PC/ED) manual.
No
GO to
C2 .
C2 CHECK THE PCM PID WACF WITH THE A/C ON
z
Turn the function selector switch to the A/C position.
z Enter the following diagnostic mode on the diagnostic Yes
REFER to the Powertrain Klj . 15 ba
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