key FORD MUSTANG 2003 Workshop Manual

DIAGNOSIS AND TESTING
Interior Lighting
Refer to Wiring Diagrams Cell
111 , Remote Control Alarm and Lock System for schematic and
connector information.
Refer to Wiring Diagrams Cell 59 , Generic Electronic Module for schematic and connector
information.
Refer to Wiring Diagrams Cell 89 , Courtesy Lamps for schematic and connector information.
Principles of Operation
Battery Saver
The battery saver feature provides automatic shut- off of power to demand and courtesy lamp circuitry.
When the generic electronic module (GEM) detects the ignition switch circuits are in the key OFF or
removed ignition key positions, power will be disabled after individual time- out periods of 30 minutes
for the demand lamps, and 10 minutes for the courtesy lamps. However, the time- out period for the
courtesy lamps changes to 30 minutes when the GEM detects that the luggage compartment lid is ajar
by means of the luggage compartment lid ajar circuit, or if the dome lamp is switched on by means of
the dome lamp circuit. When the GEM detects that the ignition switch is in the RUN, ACC, or START
positions, the battery saver feature is disabled.
The battery saver timer for the demand lamps is reset when the GEM detects that the ignition switch is
in the OFF or key out positions or when the GEM detects any one of the following conditions:
zthe driver or passenger door becomes ajar, as detected by the door ajar circuit
z the luggage compartment lid becomes ajar, as detected by the luggage compartment lid ajar
circuit
z the dome lamp switch is activated, as detected by the dome lamp switch circuit
The battery saver timer for the courtesy lamps is reset when the GEM detects that the ignition switch is
in the OFF or key out positions or when the GEM detects the driver or passenger door becomes ajar SECTION 417-
02: Interior Lighting 2003 Mustang Workshop Manual Special Tool(s)
73 Digital Multimeter or
equivalent
105-
R0051 Worldwide Diagnostic System
(WDS)
418-
F224,
New Generation STAR (NGS)
Tester
418- F052, or equivalent scan
tool Klj . 1 ba
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as detected by the door ajar circuit. For vehicles equipped with the remote keyless entry feature, any
signal the GEM detects when a valid remote transmitter button is depressed will reset both the
demand and courtesy lamp battery saver timers. This battery saver relay then restores power to both
the demand and courtesy lamp circuits.
Base Courtesy and Extended Lighting
The base courtesy lighting feature provides interior lighting for the convenience of the vehicle's
occupants. The courtesy lamps consist of the map/dome lamps for the coupe and the map lamps for
the convertible. All lamps designated as courtesy lamps will be illuminated whenever the GEM detects
that the driver or passenger doors become ajar, by means of the driver or passenger door ajar circuits.
The courtesy lamps will also be illuminated when the GEM detects that the dome lamp switch has
been activated, by means of the dome lamp switch circuit.
The extended courtesy lighting feature provides temporary extended illumination of the courtesy lamps
after the customer has entered the vehicle. The courtesy lamps will remain illuminated for 25 seconds
after the GEM detects that the driver and passenger doors are closed, as detected by the door ajar
circuits. The extended courtesy lighting feature will be terminated after the 25 second time-
out period,
or if the GEM detects that the ignition switch has been moved from the OFF position to either the RUN,
ACC, or START positions.
Demand Lighting
The GEM does not provide any special features to the demand lighting group with the exception of
providing a power source when the battery saver feature is active. The demand lighting group consists
of the luggage compartment lamp, the driver and passenger vanity mirror lamps, and the map lamps.
Illuminated Entry with Remote Keyless Entry
The illuminated entry with remote keyless entry feature, provides power to the courtesy lamps when
the remote transmitter is used. When the GEM detects that the ignition switch is in the OFF or key out
positions, and it detects that a valid remote transmitter unlock button has been depressed, power to
the courtesy lamps will be enabled. The courtesy lamp circuit will remain powered until one of the
following occurs:
zThe GEM detects that the ignition switch has been moved from the OFF, to the RUN, START,
or ACC position.
z The GEM detects any valid remote transmitter lock button is depressed.
z The courtesy lamp circuit has been powered for 25 seconds.
If the GEM detects any valid remote transmitter unlock button has been depressed, and the ignition
switch is in the OFF or key out position during the 25 second time- out, the courtesy lamp circuits will
remain powered for an additional 25 seconds.
Inspection and Verification
1. The interior lighting system is a generic electronic module (GEM) controlled system.
2. Verify the customer concern by operating the interior lighting system.
3. Visually inspect for the following obvious signs of mechanical and electrical damage. Klj . 2 ba
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battery. Failure to follow this caution will result in the GEM storing many erroneous DTCs and
may result in the GEM exhibiting erratic operation after installation.
CAUTION: Be careful when probing the central junction box (CJB), battery junction box
(BJB), or any connectors. Damage will result to the connector receptacle if the probe being
used is too large.
CAUTION: Electronic modules are sensitive to static electrical charges. If exposed to
these charges, damage may result.
NOTE: If continuous DTCs are recorded and the symptom is not present when carrying out the
pinpoint tests, an intermittent concern may be the cause. Always check for loose connections and
corroded terminals.
NOTE: Complete the entire pinpoint test related to the symptom before installing a new GEM.
PINPOINT TEST A: NO COMMUNICATION WITH THE GENERIC
ELECTRONIC MODULE Test Step Result / Action to Take
CAUTION: Use the correct probe adapter(s) when making measurements. Failure to
use the correct probe adapter(s) may damage the connector. A1 GENERIC ELECTRONIC MODULE (GEM) POWER SUPPLY
z
Key in OFF position.
z Disconnect: Generic Electronic Module (GEM) C201a.
z Disconnect: GEM C201b.
z Key in ON position.
z Using the following table, measure the voltage between the
GEM, harness side and ground.
z Are the voltages greater than 10 volts? Connector Pin Circuit
C201a 2 400 (LB/BK)
C201a 3 1006 (DG/WH)
C201b 1 1001 (WH/YE)
C201b 4 193 (YE/LG) Yes
GO to
A2 .
No
REPAIR the circuit(s) in
question. TEST the system
for normal operation. A2 CHECK THE GEM GROUND CIRCUIT 397 (BK/WH) FOR
OPEN z
Key in OFF position.
z Measure the reistance between the GEM C201b pin 2, circuit
397 (BK/WH), harness side and ground. Yes
GO to
A3 .
No
REPAIR the circuit(s) in
question. TEST the system
for normal operation. Klj . 6 ba
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PINPOINT TEST B: THE COURTESY LAMPS ARE INOPERATIVE z
Is the resistance less than 5 ohms? A3 CHECK CIRCUIT 397 (BK/WH) FOR SHORT TO POWER
z
Measure the voltage between GEM C201b pin 2, circuit 397
(BK/WH), harness side and ground.
z Is any voltage present? Yes
REPAIR the circuit. TEST
the system for normal
operation.
No
REFER to
Section 418 - 00 .
Test Step Result / Action to Take
B1 CHECK IGNITION STATES
z
Monitor the GEM PIDS IGN_KEY, IGN_A, IGN_S, and IGN_R
while cycling the ignition switch through the OFF, ACC, RUN,
START and key out positions.
z Do the PID values agree with the ignition switch
positions? Yes
GO to
B2 .
No
For key- in-ignition
concerns, REFER to
Section 413 - 09 .
B2 CHECK THE DOOR AJAR INPUT TO THE GEM
z
Monitor the GEM PID D_DOOR, and P_DOOR, while
opening and closing the driver and passenger doors.
z Do the GEM PIDS D_DOOR and P_DOOR agree with the
driver and passenger door positions? Yes
GO to
B3 .
No
REFER to Section 413 -
09 .
B3 CHECK THE DOME LAMP SWITCH STATUS INPUT TO THE
GEM — MONITOR THE GEM PID DOMESW z
Monitor the GEM PID DOMESW, while activating, and
deactivating the dome lamp switch.
z Does the GEM PID DOMESW agree with the dome lamp
switch position? Yes
GO to
B4 .
No
GO to B13 .
B4 CHECK THE LUGGAGE COMPARTMENT LID AJAR INPUT
TO THE GEM — MONITOR THE GEM PID DECKLID Klj . 7 ba
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B17 CHECK LUGGAGE COMPARTMENT SOLENOID FOR
SHORT TO GROUND z
Key in OFF position.
z Disconnect: Luggage Compartment Solenoid C430.
z Monitor the GEM PID DECKLID.
z Does the GEM PID DECKLID indicate closed? Yes
INSTALL a new luggage
compartment solenoid.
For additional information,
REFER to
Section 501 -
14A . REPEAT the self-
test. CLEAR the DTC.
No
GO to B18 .
B18 CHECK CIRCUIT 486 (BN/WH) FOR SHORT TO GROUND
z
Disconnect: GEM C201d.
z Measure the resistance between GEM C201d Pin 3, Circuit
486 (BN/WH), harness side and ground.
z Is the resistance greater than 10,000 ohms? Yes
INSTALL a new GEM. For
additional information,
REFER to
Section 419 -
10 . REPEAT the self-
test.
CLEAR the DTCs.
No
REPAIR the circuit.
REPEAT the self- test.
CLEAR the DTCs. B19 CHECK CIRCUIT 486 (BN/WH) FOR AN OPEN —
MONITOR
GEM PID DECKLID z
Disconnect: Luggage Compartment Solenoid C430.
z Monitor the GEM PID DECKLID.
z Connect a 10A fused jumper between luggage compartment
solenoid C430 Pin 3, Circuit 486 (BN/WH), harness side and
ground.
z Does the GEM PID DECKLID indicate AJAR with the
jumper installed? Yes
GO to
B21 .
No
GO to B20 .
B20 CHECK CIRCUIT 486 (BN/WH) FOR OPEN
z
Disconnect: GEM C201d.
z Measure the resistance between GEM C201d Pin 3, Circuit
486 (BN/WH), harness side and luggage compartment
solenoid C430 Pin 3, Circuit 486 (BN/WH) harness side. Yes
INSTALL a new GEM. For
additional information,
REFER to
Section 419 -
10 . REPEAT the self-
test.
CLEAR the DTCs.
No
REPAIR the circuit.
REPEAT the self- test. Klj . 11 ba
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PINPOINT TEST C: THE DEMAND LIGHTING IS INOPERATIVE z
Is the resistance less than 5 ohms? CLEAR the DTCs.
B21 CHECK GROUND CIRCUIT 1205 (BK) FOR OPEN
z
Measure the resistance between luggage compartment lid
switch C430 Pin 1, Circuit 1205 (BK), harness side and
ground.
z Is the resistance less than 5 ohms? Yes
INSTALL a new luggage
compartment solenoid.
For additional information,
REFER to
Section 501 -
14A . REPEAT the self-
test. CLEAR the DTCs.
No
REPAIR the circuit.
REPEAT the self- test.
CLEAR the DTCs. Test Step Result / Action to Take
C1 CHECK GEM SUPPLIED POWER TO THE DEMAND LAMPS
z
Turn on both map lamps by depressing the map lamp
switches.
z Turn on both vanity mirror lamps.
z Open the luggage compartment lid.
z Do any of the lamps illuminate? Yes
GO to
C8 .
No
GO to C2 .
C2 CHECK IGNITION STATES
z
Monitor the GEM PIDS IGN_KEY, IGN_A, IGN_S, and IGN_R
while cycling the ignition switch through the OFF, ACC, RUN,
START and key out positions.
z Do the PID values agree with the ignition switch
positions? Yes
GO to
C3 .
No
For key- in-ignition
concerns, REFER to
Section 413 - 09 .
C3 CHECK DRIVER AND PASSENGER DOOR AJAR INPUTS TO
THE GEM z
Monitor the GEM PIDs D_DOOR and P_DOOR, while
opening and closing the driver and passenger doors.
z Did the GEM PIDs D_DOOR and P_DOOR agree with the
driver and passenger door positions? Yes
GO to
C4 .
No
REFER to Section 413 -
09 . Klj . 12 ba
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C4 CHECK INTERIOR LAMP SWITCH INPUT TO THE GEM —
MONITOR GEM PID DOMESW z
Monitor the GEM PID DOMESW, while moving the interior
lamp switch from the OFF to the ON position.
z Does the GEM PID DOMESW values agree with the
interior lamp switch positions? Yes
GO to
C5 .
No
GO to Pinpoint Test B .
C5 CHECK THE LUGGAGE COMPARTMENT LID AJAR INPUT
TO THE GEM — MONITOR THE GEM PID DECKLID z
Monitor the GEM PID DECKLID, while opening, and closing,
the luggage compartment lid.
z Does the GEM PID DECKLID agree with the luggage
compartment lid position? Yes
GO to
C6 .
No
GO to Pinpoint Test B .
C6 CHECK CIRCUIT 705 (LG/OG) FOR OPEN
z
Turn on both map lamps using the switches in the rear view
mirror.
z Turn on both vanity mirror lamps.
z Open the luggage compartment lid.
z Disconnect: GEM C201c.
z Connect a fused jumper (20A) between GEM C201c Pin 4,
Circuit 705 (LG/OG), harness side and battery positive
terminal.
z Do the demand lamps illuminate? Yes
GO to
C7 .
No
REPAIR the circuit.
REPEAT the self- test.
CLEAR the DTCs. C7 CHECK CIRCUIT 1006 (DG/WH) FOR OPEN
NOTE:
Verify battery voltage at CJB Fuse 7 (20A) before
carrying out this test.
z Disconnect: GEM C201a.
z Measure the voltage between GEM C201a Pin 1, Circuit 1006
(DG/WH), harness side and ground.
z Is the voltage greater than 10 volts? Yes
INSTALL a new GEM. For
additional information,
REFER to
Section 419 -
10 . REPEAT the self-
test.
CLEAR the DTCs.
No
REPAIR the circuit.
REPEAT the self- test.
CLEAR the DTCs. C8 CHECK CIRCUIT 705 (LG/OG) FOR VOLTAGE AT
INOPERATIVE DEMAND LAMP z
Key in OFF position.
z Disconnect inoperative demand lamp, dome/map C929 Yes
GO to
C9 . Klj . 13 ba
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PINPOINT TEST D: THE ILLUMINATED ENTRY IS INOPERATIVE
WHEN USING THE REMOTE TRANSMITTER (coupe), map C907 (convertible), right hand vanity C906, left
hand vanity C978, or luggage compartment C4111.
z Measure the voltage between inoperative demand lamp,
Circuit 705 (LG/OG), harness side and ground.
z Is the voltage greater than 10 volts? No
REPAIR the circuit in
question. REPEAT the
self-
test. CLEAR the
DTCs. C9 CHECK CIRCUIT 1205 (BK) FOR OPEN AT INOPERATIVE
DEMAND LAMP z
Measure the resistance between inoperative demand lamp
Circuit 1205 (BK), harness side and ground.
z Is the resistance less than 5 ohms? Yes
INSTALL a new demand
lamp assembly. REPEAT
the self-
test. CLEAR the
DTCs.
No
REPAIR the circuit in
question. REPEAT the
self- test. CLEAR the
DTCs. Test Step Result / Action to Take
D1 CHECK THE REMOTE TRANSMITTER
INPUT TO THE GEM z
Remove the ignition key from the ignition.
z Depress the lock and then the unlock
buttons on the remote transmitter.
z Do the doors lock when the lock button
is depressed and unlock when the
unlock button is depressed? Yes
GO to
D2 .
No
REFER to Section 501 - 14B .
D2 CHECK OPERATION OF ILLUMINATED
ENTRY WITHOUT REMOTE TRANSMITTER z
Open the driver door.
z Do the courtesy lamps illuminate? Yes
INSTALL a new GEM. For additional
information, REFER to
Section 419 - 10 .
REPEAT the self- test. CLEAR the DTCs.
No
GO to Pinpoint Test B . Klj . 14 ba
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next step. For additional information, refer to
Section 417 - 01 .
4. Verify the parking brake control is fully released.
5. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
6. If the concern is not visually evident, verify the symptom and refer to the Symptom Chart.
Symptom Chart
Pinpoint Tests
PINPOINT TEST A: THE DAYTIME RUNNING LAMPS ARE
INOPERATIVE Symptom Chart Condition
Possible Sources Action
z The daytime running lamps are
inoperative z
BJB Maxi- Fuse
FOG+DRL (20A).
z Circuitry.
z Parking brake
signal switch and
bracket.
z DRL module. z
GO to
Pinpoint Test A .
z The daytime running lamps are
on with the parking brake set z
Circuitry.
z Parking brake
signal switch and
bracket.
z DRL module. z
GO to
Pinpoint Test B .
z The daytime running lamps are
on with the ignition switch off z
Circuitry.
z Ignition switch.
z DRL module. z
GO to
Pinpoint Test C .
z The low beam headlamps are on
at full intensity in DRL mode z
Circuitry.
z Headlamp switch.
z DRL module. z
GO to
Pinpoint Test D .
z The low beam headlamps are on
at reduced intensity with the
headlamp switch on z
Circuitry.
z Headlamp switch. z
REFER to
Section 417 -
01 .
Test Step Result / Action to Take
A1 CHECK THE PARKING BRAKE SWITCH SIGNAL
CIRCUIT TO THE DRL MODULE FOR SHORT TO GROUND NOTE:
Verify the parking brake control is fully released
for this step.
z Key in OFF position.
z Disconnect: DRL Module C1030.
z Measure the resistance between DRL module C1030 Pin
6, Circuit 22 (LB/BK), harness side and ground. Yes
GO to
A3 .
No
GO to A2 . Klj . 2 ba
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z
Is the resistance greater than 10,000 ohms? A2 CHECK THE PARKING BRAKE SWITCH
z
Disconnect: Parking Brake Switch C306.
z Measure the resistance between DRL module C1030 Pin
6, Circuit 22 (LB/BK), harness side and ground.
z Is the resistance greater than 10,000 ohms? Yes
INSTALL a new parking brake
signal switch and bracket.
TEST the system for normal
operation.
No
REPAIR the circuit. TEST the
system for normal operation.
A3 CHECK VOLTAGE TO THE DRL MODULE
z
Measure the voltage between DRL module C1030 Pin 2,
Circuit 477 (LB/BK), harness side and ground.
z Is the voltage greater than 10 volts? Yes
GO to
A4 .
No
REPAIR the circuit. TEST the
system for normal operation. A4 CHECK IGNITION SENSE INPUT
z
Key in ON position.
z Measure the voltage between DRL module C1030 Pin 3,
Circuit 298 (VT/OG), harness side and ground. Yes
GO to
A5 .
No
REPAIR the circuit. TEST the
system for normal operation. Klj . 3 ba
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