2003 FORD MUSTANG pinpoint

z
speed control actuator switches.
z brake pedal position (BPP) switch.
z clutch pedal position (CPP) switch.
z deactivator switch.
The output of the speed control servo is the:
zspeed control actuator cable controlling the throttle position.
Inspection and Verification
NOTE: If any concerns are noted with the speedometer, stoplamps, or horn, address those concerns
by referring to their associated sections before continuing speed control diagnosis.
1. Verify the customer concern by operating the speed control system.
2. Visually inspect for obvious signs of mechanical and electrical damage.
3. If the fault is not visually evident, verify the symptom and GO to the Symptom chart.
Symptom Chart
NOTE: New speed control diagnostic software is available in Version 12 or higher for the diagnostic
tool. When using this software, it is necessary to use Next Generation Speed Control Adapter 007-
00586 with the diagnostic tool.
NOTE: Refer to the Wiring Diagrams for connector numbers stated in the Pinpoint Test.
Visual Inspection Chart Mechanical Electrical
z
Deactivator switch
z Speed control actuator cable not attached to throttle
z Speed control actuator cable not fully seated to the
engine bracket z
Central junction box (CJB)
Fuse:
„15 (15A)
„ 33 (15A)
„ 35 (15A)
z Battery junction box (BJB)
fuse:
„HORN (20A)
z Wiring harness
z Loose or corroded
connections
z Speed control actuator
switches
Symptom Chart Condition
Possible Sources Action
z The speed control is zCentral junction zGo To Pinpoint Test A . Klj . 2 ba
132003 Mustang Workshop Manual
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inoperative
box (CJB) fuse
17 (15A), 33
(15A).
z Battery junction
box (BJB) fuse
HORN (20A).
z Circuitry.
z Deactivator
switch.
z Clutch pedal
position (CPP)
switch.
z Speed control
actuator switch.
z Speed control
servo.
z Powertrain
control module
(PCM).
z The set speed
fluctuates z
Circuitry.
z Speed control
servo.
z Powertrain
control module
(PCM). z
Go To Pinpoint Test B .
z Engine. zREFER to the Powertrain
Control/Emissions
Diagnosis (PC/ED)
manual.
z The speed control
does not disengage
when the brakes are
applied z
Central junction
box (CJB) fuse
33 (15A).
z Circuitry.
z Brake pedal
position (BPP)
switch.
z Speed control
servo. z
Go To Pinpoint Test C .
z The speed control
does not disengage
when the clutch is
applied z
Cluch pedal
position (CPP)
switch.
z Speed control
servo. z
Go To Pinpoint Test D .
z The speed control
switch is
inoperative— COAST z
Speed control
actuator switch.
z Speed control
servo. z
Go To Pinpoint Test E .
z The speed control
switch is
inoperative—
SET/ACCEL z
Speed control
actuator switch.
z Speed control
servo. z
Go To Pinpoint Test F .
z The speed control
switch is
inoperative—
RESUME z
Speed control
actuator switch.
z Speed control
servo. z
Go To Pinpoint Test G .
z The speed control
switch is
inoperative— OFF z
Speed control
actuator switch.
z Speed control
servo. z
Go To Pinpoint Test H . Klj . 3 ba
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Pinpoint Tests
PINPOINT TEST A: THE SPEED CONTROL IS INOPERATIVE
Test Step Result / Action to Take
A1 CHECK THE SPEED CONTROL SERVO VOLTAGE AND
GROUND z
Key in OFF position.
z Disconnect: Speed Control Servo C122.
z Key in ON position.
z Measure the voltage between speed control servo C122 Pin 7,
Circuit 294 (WH/LB), harness side and speed control servo
C122 Pin 10, Circuit 1205 (BK), harness side.
z Is voltage greater than 10 volts? Yes
GO to
A3 .
No
GO to A2 .
A2 CHECK THE CIRCUIT 1205 (BK) FOR AN OPEN
z
Key in OFF position.
z Measure the resistance between speed control servo C122 Pin
10, Circuit 1205 (BK), harness side and ground.
z Is the resistance less than 5 ohms? Yes
REPAIR Circuit 294
(WH/LB). TEST the
system for normal
operation.
No
REPAIR Circuit 1205
(BK). TEST the system
for normal operation.
A3 CHECK DEACTIVATOR SWITCH CIRCUITRY
z
Measure the voltage between speed control servo C122 Pin 9,
Circuit 636 (OG), harness side and speed control servo C122
Pin 10, Circuit 1205 (BK), harness side. Yes
GO to
A6 .
No
GO to A4 . Klj . 4 ba
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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
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PINPOINT TEST C: THE SPEED CONTROL DOES NOT DISENGAGE
WHEN THE BRAKES ARE APPLIED
PINPOINT TEST D: THE SPEED CONTROL DOES NOT DISENGAGE
WHEN THE CLUTCH IS APPLIED B2 CHECK THE SPEED CONTROL
ACTUATOR CABLE z
NOTE: The speed control actuator cable
must be disconnected at both ends while
carrying out this test.
z Check the speed control actuator cable
for sticking or binding at the speed
control servo and throttle body.
z Is the speed control actuator cable
OK? Yes
GO to
B3 .
No
INSTALL a new speed control actuator cable;
REFER to Actuator Cable — Speed Control .
TEST the system for normal operation. B3 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
C1 CHECK THE BPP SWITCH CIRCUITRY
z
Key in OFF position.
z Disconnect: Speed Control Servo C122 .
z Measure the voltage between speed control servo C122 Pin 4,
Circuit 511 (LG), harness side and speed control servo C122
Pin 10, Circuit 1205 (BK), harness side, while depressing the
brake pedal.
z Is the voltage greater than 10 volts? Yes
INSTALL a new speed
control servo; REFER to
Actuator
— Speed
Control Servo . TEST
the system for normal
operation.
No
REPAIR Circuit 810
(RD/LG) and Circuit 511
(LG) as necessary.
TEST the system for
normal operation. Test Step Result / Action to Take
D1 CHECK THE CLUTCH PEDAL POSITION (CPP) SWITCH
z
Key in OFF position.
z Disconnect: CPP Switch C2072.
z Measure the resistance between CPP switch pin 2
(component side) and CPP switch pin 1 (component side), Yes
INSTALL a new speed
control servo; REFER to
Actuator
— Speed Control Klj . 10 ba
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PINPOINT TEST E: THE SPEED CONTROL SWITCH IS
INOPERATIVE—
COAST
PINPOINT TEST F: THE SPEED CONTROL SWITCH IS
INOPERATIVE— SET/ACCEL while depressing and releasing clutch pedal.
z Is the resistance greater than 10,000 ohms with the
clutch pedal depressed and less than 5 ohms with the
clutch pedal released? Servo . TEST the system
for normal operation.
No
INSTALL a new CPP
switch. TEST the system
for normal operation. Test Step Result / Action to
Take E1 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 COAST.
z Is the resistance between 108 and 132 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 F1 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 SET/ACCEL. Yes
INSTALL a new speed
control servo; REFER
to
Actuator — Speed
Control Servo . TEST
the system for normal
operation. Klj . 11 ba
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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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