2003 FORD MUSTANG test G

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
162003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

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
162003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

PINPOINT TEST E: THE BATTERY SAVER DOES NOT DEACTIVATE
AFTER TIMEOUT
Test Step Result / Action to Take
E1 CHECK THE GEM CONTROL OF THE BATTERY SAVER
FUNCTION — TRIGGER THE GEM ACTIVE COMMAND BATT
SAVR ON z
Trigger the GEM active command BATT SAVR ON and then
OFF.
z Do the courtesy lamps illuminate and turn off when the
GEM active command BATT SAVR is triggered ON and
OFF? Yes
INSTALL a new GEM.
For additional
information, REFER to
Section 419
- 10 .
REPEAT the self- test.
CLEAR the DTCs.
No
GO to E2 .
E2 CHECK CIRCUITS 1034 (BK/WH), AND 705 (LG/OG), FOR
SHORT TO BATTERY z
Disconnect: GEM C201c.
z Measure the voltage between GEM C292 Pin 3, Circuit 1034
(BK/WH), harness side and ground; and between GEM C292
Pin 4, Circuit 705 (LG/OG), harness side and ground.
z Is the voltage greater than 10 volts? Yes
REPAIR the circuit in
question. REPEAT the
self-
test. CLEAR the
DTCs.
No
INSTALL a new GEM.
For additional
information, REFER to
Section 419 - 10 .
REPEAT the self- test.
CLEAR the DTCs. Klj . 15 ba
162003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

DIAGNOSIS AND TESTING
Daytime Running Lamps (DRL)
Refer to Wiring Diagrams Cell
97 , Daytime Running Lamps for schematic and connector information.
Principles of Operation
Daytime Running Lamps (DRL)
The daytime running lamps (DRL) system operates the low beam headlamps at a reduced intensity.
The DRL module (15A270) supplies pulse width modulated (PWM) voltage, approximately 75%- 92%
of battery voltage, to the low beam headlamps when the following conditions are met:
zThe parking brake control is released.
z The high beam headlamps are disabled.
z The ignition switch (11572) is in the RUN position.
The DRL module remains enabled when the low beam headlamps are turned on.
Inspection and Verification 1. Verify the customer concern by operating the system.
2. Visually inspect for obvious signs of mechanical and electrical damage.
3. Verify the headlamps are operating correctly. Correct any concerns before proceeding to the
SECTION 417-
04: Daytime Running Lamps 2003 Mustang Workshop Manual Special Tool(s)
73III Automotive Meter or
equivalent
105-
R0057
Visual Inspection Chart Mechanical Electrical
z
Damaged DRL module
z Damaged parking brake signal switch and
bracket (15A851) z
Blown battery junction box (BJB) Maxi-
Fuse FOG+DRL (20A)
z Damaged wiring harness
z Loose or corroded connection
z Damaged DRL module
z Damaged parking brake signal switch and
bracket Klj . 1 ba
62003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

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
62003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

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
62003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

PINPOINT TEST B: THE DAYTIME RUNNING LAMPS ARE ON WITH
THE PARKING BRAKE SET z
Is the voltage greater than 10 volts? A5 CHECK THE DRL MODULE GROUND —
CIRCUIT 1205
(BK) z
Measure the resistance between DRL module C1030 Pin
4, Circuit 1205 (BK), harness side and ground.
z Is the resistance less than 5 ohms? Yes
GO to
A6 .
No
REPAIR the circuit. TEST the
system for normal operation. A6 CHECK THE HIGH BEAM DISABLE INPUT CIRCUIT FOR
SHORT TO BATTERY — CIRCUIT 12 (LG/BK) z
Measure the voltage between DRL module C1030 Pin 5,
Circuit 12 (LG/BK), harness side and ground.
z Is voltage indicated? Yes
REPAIR the circuit. TEST the
system for normal operation.
No
INSTALL a new DRL module.
REFER to
Module — Daytime
Running Lamps (DRL) . TEST
the system for normal
operation. Test Step Result / Action to Take
B1 CHECK THE PARKING BRAKE SWITCH
z
Key in OFF position.
z Disconnect: Parking Brake Switch C306.
z Connect a 10A fused jumper wire between parking brake
switch C306, Circuit 22 (LB/BK), harness side and ground.
z Key in ON position. Yes
INSTALL a new parking
brake signal switch and
bracket. TEST the system
for normal operation.
No
GO to
B2 . Klj . 4 ba
62003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

PINPOINT TEST C: THE DAYTIME RUNNING LAMPS ARE ON WITH
THE IGNITION SWITCH OFF z
Do the DRL turn off? B2 CHECK THE PARKING BRAKE SWITCH SIGNAL CIRCUIT
z
Key in OFF position.
z Disconnect: DRL Module C1030.
z Measure the resistance between parking brake switch C306,
Circuit 22 (LB/BK), harness side and DRL module C1030 Pin
6, Circuit 22 (LB/BK), harness side.
z Is the resistance less than 5 ohms? Yes
INSTALL a new DRL
module. REFER to
Module
— Daytime
Running Lamps (DRL) .
TEST the system for
normal operation.
No
REPAIR the circuit. TEST
the system for normal
operation. Test Step Result / Action to Take
C1 CHECK THE IGNITION SWITCH INPUT TO THE DRL
MODULE FOR VOLTAGE z
Key in OFF position.
z Disconnect: DRL Module C1030.
z Measure the voltage between DRL module C1030 Pin 3,
Circuit 298 (VT/OG), harness side and ground.
z Is voltage indicated? Yes
GO to
C2 .
No
INSTALL a new DRL module.
REFER to Module — Daytime
Running Lamps (DRL) . TEST
the system for normal
operation. C2 CHECK THE IGNITION SWITCH
z
Check the ignition switch; refer to the Wiring Diagrams
Cell 149.
z Is the ignition switch OK? Yes
REPAIR Circuit 298 (VT/OG)
for short to battery. TEST the
system for normal operation.
No
INSTALL a new ignition switch.
REFER to
Section 211 - 05 .
TEST the system for normal
operation. Klj . 5 ba
62003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...