2003 FORD MUSTANG test G

DIAGNOSIS AND TESTING
Speed Control
Refer to Wiring Diagrams Cell
31 , Speed Control for schematic and connector information.
Principles of Operation
The speed control system is designed to maintain vehicle speed above 48 km/h (30 mph). After the
ON switch is depressed, depressing the SET/ACCEL switch will activate the speed control servo. To
increase a set speed, either depress and hold for continuous acceleration, or momentarily tap the
SET/ACCEL switch for 1.6 km/h (1 mph) acceleration increments. To decrease a set speed, depress
and hold the COAST switch until the target speed is reached, or momentarily tap the COAST switch
for 1.6 km/h (1 mph) deceleration increments. When the speed control system has been disabled by
tapping the brake pedal, the RESUME switch can be depressed and the vehicle will return to the
original set speed if the vehicle is traveling over 48 km/h (30 mph) and the OFF switch has not been
depressed.
NOTE: The deactivator switch is provided as an additional safety feature. Normally, when the brake
pedal is depressed, an electrical signal from the brake lamp circuit to the speed control servo will
deactivate the system. Under increased brake pedal effort, the deactivator switch will open and
remove power to the speed control servo, releasing the throttle independent of the speed control
servo.
NOTE: The air bag sliding contract provides the electrical interface between the steering column wiring
and the speed control actuator switches in the steering wheel.
The inputs to the speed control servo are the:
zvehicle speed signal.
SECTION 310-
03: Speed Control 2003 Mustang Workshop Manual Special Tool(s)
Worldwide Diagnostic System
(WDS)
418-
F224,
New Generation STAR (NGS)
Tester
418- F052, or equivalent
diagnostic tool 73 Digital Multimeter or
equivalent
105-
R0051 Breakout Box, EEC-V Control
System 418-049, or equivalent
014- 00950 Klj . 1 ba
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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
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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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z
Is the voltage greater than 10 volts? A4 CHECK CIRCUIT 10 (LG/RD) FOR AN OPEN
z
Disconnect: Deactivator Switch C2210.
z Measure the voltage between deactivator switch C2210 Pin 1,
Circuit 10 (LG/RD), harness side and ground.
z Is the voltage greater than 10 volts? Yes
GO to
A5 .
No
REPAIR the circuit.
TEST the system for
normal operation. A5 CHECK CIRCUIT 636 (OG) FOR AN OPEN
z
Measure the resistance between speed control servo C122 Pin
9, Circuit 636 (OG), harness side and deactivator switch C2210
Pin 2, Circuit 636 (OG), harness side.
z Is the resistance less than 5 ohms? Yes
INSTALL a new
deactivator switch;
REFER to
Switch —
Deactivator . TEST the
system for normal
operation.
No
REPAIR the circuit.
TEST the system for
normal operation. A6 CHECK THE SPEED CONTROL ACTUATOR SWITCH ON
CIRCUITRY z
Measure the voltage between speed control servo C122 Pin 5,
Circuit 151 (LB/BK), harness side and speed control servo C122
Pin 10, Circuit 1205 (BK), harness side, while the speed control
actuator switch ON is depressed. Yes
GO to
A9 .
No
GO to A7 . Klj . 5 ba
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z
Is the voltage greater than 10 volts? A7 CHECK CIRCUIT 151 (LB/BK) FOR AN OPEN
z
Disconnect: Air Bag Sliding Contact C218a.
z Measure the resistance between speed control servo C122 Pin
5, Circuit 151 (LB/BK), harness side and air bag sliding contact
C218a Pin 4, Circuit 151 (LB/BK), harness side.
z Is the resistance less than 5 ohms? Yes
GO to
A8 .
No
REPAIR the circuit.
TEST the system for
normal operation. A8 CHECK THE AIR BAG SLIDING CONTACT
z
Remove the air bag; REFER to Section 501 - 20B .
z Disconnect: Speed Control Actuator Switch.
z Measure the resistance between bottom of air bag sliding
contact Pin 1 (component side) and top of air bag sliding
contact Pin 3 (component side).
z Is the resistance less than 5 ohms? Yes
INSTALL a new speed
control actuator switch;
REFER to
Switch —
Speed Control
Actuator . TEST the
system for normal
operation.
No
INSTALL a new air bag
sliding contact; REFER
to Section 501 - 20B .
TEST the system for
normal operation. A9 CHECK THE SPEED CONTROL ACTUATOR SWITCH ON
CIRCUITRY FOR SHORT TO POWER z
Key in ON position.
z Measure the voltage between speed control servo C122 Pin 5,
Circuit 151 (LB/BK), harness side and speed control servo C122
Pin 10, Circuit 1205 (BK), harness side. Yes
GO to
A10 .
No
GO to A12 . Klj . 6 ba
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z
Is any voltage present? A10 CHECK CIRCUIT 151 (LB/BK) FOR SHORT TO POWER
z
Key in OFF position.
z Disconnect: Air Bag Sliding Contact C218a.
z Key in ON position.
z Measure the voltage between speed control servo C122 Pin 5,
Circuit 151 (LB/BK), harness side and speed control servo C122
Pin 10, Circuit 1205 (BK), harness side.
z Is any voltage present? Yes
REPAIR the circuit.
TEST the system for
normal operation.
No
GO to
A11 .
A11 CHECK THE AIR BAG SLIDING CONTACT
z
Key in OFF position.
z Remove the air bag; REFER to Section 501 - 20B .
z Disconnect: Speed Control Actuator Switch.
z Key in ON position.
z Measure the voltage between bottom of air bag sliding contact
Pin 1 (component side) and ground.
z Is any voltage present? Yes
INSTALL a new air bag
sliding contact; REFER
to Section 501
- 20B .
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. A12 CHECK THE SPEED CONTROL ACTUATOR SET/ACCEL
CIRCUITRY z
Key in OFF position.
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 the speed
control actuator switch SET/ACCEL is depressed. Yes
GO to
A13 .
No
INSTALL a new speed
control actuator switch; Klj . 7 ba
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z
Is the resistance between 612 and 748 ohms? REFER to
Switch —
Speed Control
Actuator . TEST the
system for normal
operation. A13 CHECK THE BPP SWITCH CIRCUITRY
z
Measure the resistance between speed control servo C122 Pin
4, Circuit 511 (LG), harness side, and speed control servo C122
Pin 10, Circuit 1205 (BK), harness side.
z Is the resistance less than 20 ohms? Yes
GO to
A16 .
No
If automatic
transmission, REPAIR
Circuit 511 (LG) and
Circuit 810 (LG/RD) as
necessary. TEST the
system for normal
operation.
If manual transmission,
GO to A14 .
A14 CHECK CIRCUIT 511 (LG) AND CIRCUIT 810 (RD/LG) FOR
AN OPEN z
Disconnect: CPP Switch C2072.
z Measure the resistance between CPP Switch C2072 Pin 1,
Circuit 511 (LG), harness side and ground.
z Is the resistance less than 20 ohms? Yes
GO to
A15 .
No
REPAIR Circuit 511
(LG) and Circuit 810
(LG/RD) as necessary.
TEST the system for
normal operation. A15 CHECK CIRCUIT 511 (LG) FOR AN OPEN
z
Measure the resistance between speed control servo C122 Pin
4, Circuit 511 (LG), harness side and CPP switch C2072 Pin 2,
Circuit 511 (LG), harness side. Yes
INSTALL a new CPP
switch. TEST the
system for normal
operation.
No
REPAIR the circuit.
TEST the system for
normal operation. Klj . 8 ba
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