pinpoint test b FORD MUSTANG 2003 Workshop Manual

PINPOINT TEST G: THE SPEED CONTROL SWITCH IS
INOPERATIVE —
RESUME
PINPOINT TEST H: THE SPEED CONTROL SWITCH IS
INOPERATIVE— OFF z
Is the resistance between 612 and 748 ohms? No
INSTALL a new speed
control actuator switch;
REFER to
Switch —
Speed Control
Actuator . TEST the
system for normal
operation. Test Step Result / Action to
Take G1 CHECK THE SPEED CONTROL ACTUATOR SWITCH
z
Key in OFF position.
z Disconnect: Speed Control Servo C122.
z Measure the resistance between speed control servo C122 Pin
5, Circuit 151 (LB/BK), harness side and speed control servo
C122 Pin 6, Circuit 848 (DG/OG), harness side while pressing
the speed control actuator switch RESUME.
z Is the resistance between 1,980 and 2,420 ohms? Yes
INSTALL a new speed
control servo; REFER
to
Actuator — Speed
Control Servo . TEST
the system for normal
operation.
No
INSTALL a new speed
control actuator switch;
REFER to Switch —
Speed Control
Actuator . TEST the
system for normal
operation. Test Step Result / Action to
Take H1 CHECK THE SPEED CONTROL ACTUATOR SWITCH
z
Key in OFF position.
z Disconnect: Speed Control Servo C122.
z Measure the resistance between speed control servo C122 Pin
5, Circuit 151 (LB/BK), harness side and speed control servo
C122 Pin 6, Circuit 848 (DG/OG), harness side while pressing
the speed control actuator switch OFF. Yes
INSTALL a new speed
control servo; REFER
to
Actuator — Speed
Control Servo . TEST
the system for normal
operation.
No Klj . 12 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 Tests
PINPOINT TEST P1464: DTC P1464: A/C DEMAND OUT OF SELF-
TEST RANGE high speed
motor switch resistor.
z Damaged heater blower
motor switch. Test H .
z No operation in high
blower setting z
Circuitry short/open.
z Damaged heater blower
motor switch. z
Go To Pinpoint
Test I .
z No operation in lower
speeds z
Circuitry short/open.
z Damaged heater blower
motor switch resistor.
z Damaged heater blower
motor switch. z
Go To Pinpoint
Test J .
Test Step Result / Action to Take
P14641 RECHECK FOR THE DTC
z
Key in ON position.
z Make sure the function selector switch is in the OFF
position.
z Enter the following diagnostic mode on the diagnostic
tool: PCM Self- Test.
z Is DTC P1464 retrieved? Yes
GO to
P14642 .
No
The system is functioning
correctly. This DTC will set if the
A/C is turned on when carrying
out the PCM self- test. P14642 CHECK PID ACCS WITH THE A/C CONTROL
DISCONNECTED z
Key in OFF position.
z Disconnect: Function Selector Switch C294c.
z Key in ON position.
z Enter the following diagnostic mode on the diagnostic
tool: PCM PID ACCS.
z Does PID ACCS read ON? Yes
GO to
P14643 .
No
INSTALL a new function selector
switch. REFER to Section 412 -
04 . REPEAT the PCM self-test
and verify DTC P1464 is no
longer retrieved. P14643 CHECK CIRCUIT 348 (VT) FOR A SHORT TO B+
z
Key in OFF position.
z Disconnect: PCM C175.
z Key in ON position.
z Measure the voltage at the function selector switch
C294c- 4, circuit 348 (VT), the harness side and ground. Yes
REPAIR circuit 348 (VT ) for a
short to B+. REPEAT the PCM
self-
test and verify DTC P1464 is
no longer retrieved.
No
INSTALL a new powertrain
control module. REFER to
Section 303 - 14 . REPEAT the
PCM self- test and verify DTC
P1464 is no longer retrieved. Klj . 7 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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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
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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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PINPOINT TEST D: THE A/C IS ALWAYS ON z
Is the resistance less than 5 ohms? No
REPAIR circuit 1205 (BK) for
an open. TEST the system for
normal operation.
Test Step Result / Action to Take
D1 CHECK PCM PID WACF
z
Turn the function selector switch to the OFF position.
z Key in ON position.
z Enter the following diagnostic mode on the diagnostic
tool: PCM PID WACF.
z Does the PCM PID WACF read YES? Yes
REPAIR circuit 331 (PK/YE) for
a short to ground. TEST the
system for normal operation.
No
GO to
D2 .
D2 CHECK PID ACCS WITH A/C OFF
z
Enter the following diagnostic mode on the diagnostic
tool: PCM PID ACCS.
z Does the PCM PID ACCS read ON? Yes
GO to
D3 .
No
GO to D5 .
D3 CHECK FOR A FALSE INPUT SIGNAL TO THE PCM
z
Key in OFF position.
z Disconnect: PCM C175.
z Key in ON position.
z Turn the function selector switch to the OFF position.
z Measure the voltage between PCM C175- 41, circuit 198
(DG/OG) harness side and ground.
z Is the voltage greater than 10 volts? Yes
GO to
D4 .
No
INSTALL a new powertrain
control module. REFER to
Section 303 - 14 . TEST the
system for normal operation. D4 CHECK CIRCUIT 198 (DG/OG) FOR A SHORT TO B+
z
Key in OFF position.
z Disconnect: Function Selector Switch C294c.
z Connect: PCM C175.
z Key in ON position.
z Measure the voltage at the function selector switch Yes
REPAIR circuit 348 (PK) for a
short to B+. TEST the system
for normal operation. Klj . 24 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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PINPOINT TEST F: NO OPERATION IN ALL TEMPERATURE
SETTINGS
PINPOINT TEST G: THE BLOWER MOTOR DOES NOT
OPERATE/DOES NOT OPERATE CORRECTLY INSTALL a new A/C
compressor due to low
performance. REFER to
Section 412
- 03 . TEST the
system for normal operation. Test Step Result / Action to Take
F1 CHECK THE TEMPERATURE CONTROL
z
Start the engine and run at idle. Allow the engine to reach
normal operating temperature.
z Place the function selector switch in the NORMAL A/C
position.
z Adjust the temperature control to full warm position, and
physically feel the discharge air temperature at the at the
center panel vents.
z Rotate the temperature control to full cold position, and
physically feel the discharge air temperature at the center
panel vents.
z Does the discharge air temperature vary? Yes
The temperature blend
door is functioning
correctly. RETURN to the
symptom chart.
No
GO to
F2 .
F2 CHECK FOR A BROKEN A/C TEMPERATURE CONTROL
CABLE z
Remove the climate control assembly to gain access to the
control cable head.
z Move the temperature control from full warm to full cold.
z Inspect the cable control head as you move the temperature
control.
z Does the alignment mark on the control head move? Yes
INSTALL a new
evaporator housing.
REFER to
Section 412 -
02 .
No
INSTALL a new
temperature control cable
assembly. REFER to
Section 412 - 04 .
Test Step Result / Action to Take
G1 CHECK FOR VOLTAGE AT C238
z
Disconnect: Blower Motor Jumper C238.
z Key in ON position.
z Turn the blower motor selector to LOW.
z Turn the function selector to FLOOR.
z Check for voltage between C238- 6, circuit 249 (DB/LG) and
C238- 3, circuit 261 (OG/BK). Yes
GO to
G2 .
No
GO to G4 . Klj . 30 ba
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PINPOINT TEST H: THE BLOWER MOTOR OPERATES
CONTINUOUSLY IN HIGH SPEED z
Check the resistance between C294a- 3, circuit 1205 (B/K)
harness side and ground.
z Is the resistance less than 5 ohms? Test Step Result / Action to Take
H1 CHECK THE FUNCTION SELECTOR SWITCH
z
Key in ON position.
z Set the blower motor speed to low.
z Check for blower motor operation in each function
selector switch position.
z Does the blower motor operate on high in all of
the function selector positions? Yes
GO to
H2 .
No
If the blower motor operates in the
OFF position, GO to H4 .
H2 CHECK CIRCUIT 261 (OG/BK) FOR A SHORT TO
GROUND z
Key in OFF position.
z Disconnect: A/C Blower Motor C2066.
z Disconnect: Blower Motor Resistor C2185.
z Disconnect: Blower Motor Switch C294a.
z Measure the resistance between C2066 circuit 261
(OG/BK), and ground.
z Is the resistance greater than 10,000 ohms? Yes
GO to
H3 .
No
REPAIR circuit 261 (OG/BK) for a
short to ground. TEST the system
for normal operation. H3 CHECK THE BLOWER MOTOR SWITCH
OPERATION z
Measure the resistance of the blower motor switch.
Refer to the chart shown.
Blower Motor Switch Test Switch
Position Conductivity Between
Terminals Yes
INSTALL a new heater blower
motor switch resistor. REFER to
Section 412
- 04 . TEST the
system for normal operation.
No Klj . 34 ba
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