key battery FORD MUSTANG 2003 Service Manual

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

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

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 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~ ...

Pinpoint Tests
CAUTION: Be careful when probing the CJB, battery junction box (BJB) or any
connectors. Damage will result to the connector receptacle if the probe or terminal being used
is too large.
CAUTION: Electronic modules are sensitive to static electrical charges. If exposed to
these charges, damage may result.
NOTE: If 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 pins.
PINPOINT TEST A: THE MODULE DOES NOT RESPOND TO THE
DIAGNOSTIC TOOL — ANTI-LOCK BRAKE CONTROL MODULE tool —
instrument cluster zInstrument cluster. Test D .
z The module does not
respond to the diagnostic
tool — powertrain control
module (PCM) z
Wire or connection in SCP
communication network.
z PCM. z
GO to
Pinpoint Test E .
z No module/network
communication — ISO 9141
network z
Wire or connection in ISO
9141 communication
network.
z ISO 9141 networked
modules. z
GO to
Pinpoint Test F .
z No module/network
communication — SCP
network z
Wire or connection in SCP
communication network.
z SCP networked modules. z
GO to
Pinpoint Test G .
z No module/network
communication — no power
to the diagnostic tool z
CJB Fuse 31 (5A).
z DLC pins.
z Scan tool.
z Circuitry. z
GO to
Pinpoint Test H .
Test Step Result / Action to Take
A1 CHECK THE VEHICLE FOR TRACTION CONTROL
z
Check the vehicle for a traction control disable switch.
z Is a traction control disable switch present? Yes
GO to
A2 .
No
GO to A9 .
A2 CHECK ANTI-
LOCK BRAKE CONTROL MODULE C141
FOR DAMAGE z
Key in OFF position.
z Disconnect: Anti- Lock Brake Control Module C135.
z Inspect the anti- lock brake control module C135 for
damage; repair as necessary.
z Connect: Anti- Lock Brake Control Module C135.
z Connect the diagnostic tool.
z Key in ON position.
z Enter the following diagnostic mode on the diagnostic
tool: Diagnostic Data Link. Yes
GO to
A3 .
No
GO to A6 . Klj . 4 ba
212003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

DESCRIPTION AND OPERATION
Anti-
Theft — Passive Anti- Theft System (PATS)
The passive anti- theft system (PATS) contains the following components:
z theft indicator
z encoded ignition key
z transceiver module
z instrument cluster
z powertrain control module (PCM)
z standard corporate protocol (SCP) communication network
The PATS uses radio frequency identification technology to deter a driveaway theft. Passive means
that it does not require any activity from the user. This system is known as SecuriLock® in North
America, Safeguard® in the U.K. and PATS in continental Europe. This information can be found in
owners literature.
The PATS uses a specially encoded ignition key. Each encoded ignition key contains a permanently
installed electronic device called a transponder. Each transponder contains a unique electronic
identification code, with over 72 million billion combinations.
Each encoded ignition key must be programmed into the vehicle's instrument cluster (the instrument
cluster is also known as a hybrid electronic cluster [HEC]), before it can be used to start the engine.
There are special diagnostic procedures outlined in the workshop manual that must be carried out if
new encoded ignition keys are to be installed.
The encoded key is larger than a traditional ignition key. The key does not require batteries and should
last the life of the vehicle.
The transceiver module communicates with the encoded ignition key. This module is located behind
the steering column shroud and contains an antenna connected to a small electronics module. During
each vehicle start sequence, the transceiver module reads the encoded ignition key identification code
and sends the data to the instrument cluster.
The control functions are contained in the instrument cluster. This module carries out all of the PATS
functions such as receiving the identification code from the encoded ignition key and controlling engine
enable. The instrument cluster initiates the key interrogation sequence when the vehicle ignition switch
is turned to RUN or START.
The PATS uses the PCM to enable or disable the engine. The instrument cluster communicates with
the PCM over the SCP network in order to enable engine operation. The instrument cluster and the
PCM use sophisticated messages in order to prevent a theft. The instrument cluster and the PCM
share security data (when first installed together) that makes them a matched pair. After this security
data sharing, these modules will not function in other vehicles. The shared PCM ID is remembered
even if the battery is disconnected. The instrument cluster also stores the vehicle's key identification
code even if the battery is disconnected. There are special diagnostic procedures outlined in this
workshop manual that may be carried out if either a new instrument cluster or PCM needs to be
installed.
All elements of PATS must be functional before the engine is allowed to start. If any of the components
are not working correctly, the vehicle will not start.
PATS uses a visual theft indicator. This indicator will prove out for three seconds when the ignition SECTION 419-
01: Anti-Theft — PATS 2003 Mustang Workshop Manual Klj . 1 ba
22003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

z
check the connections to the vehicle.
z check the ignition switch position.
4. If the diagnostic tool still does not communicate with the vehicle, refer to the diagnostic tool manual.
5. Carry out the DATA LINK DIAGNOSTIC TEST. If diagnostic tool responds with: zCKT914, CKT915 or CKT70 = ALL ECUS NO RESP/NOT EQUIP, refer to Section 418 -
00 .
z NO RESP/NOT EQUIP for instrument cluster, go to Pinpoint Test A.
z SYSTEM PASSED, retrieve and record the continuous diagnostic trouble codes (DTCs),
erase the continuous DTCs and carry out self- test diagnostics for the instrument cluster.
6. If the DTCs retrieved are related to the concern, go to Instrument Cluster Diagnostic Trouble Code (DTC) Index to continue diagnostics.
7. If no DTCs related to the concern are retrieved, proceed to Symptom Chart to continue diagnostics.
Instrument Cluster Diagnostic Trouble Code (DTC) Index Instrument Cluster Diagnostic Trouble Code (DTC) Index DTC Description Source Action
B1202 Fuel Sender Open Circuit ICM REFER to
Section 413
- 01 .
B1204 Fuel Sender Short to Ground ICM REFER to
Section 413
- 01 .
B1213 Anti-
Theft Number of Programmed Keys is Below
Minimum ICM GO to
Pinpoint Test D .
B2103 or
B1232 Antenna Not Connected —
Defective Transceiver ICM GO to
Pinpoint Test E .
B1317 Battery Voltage High ICM REFER to
Section 414
- 00 .
B1318 Battery Voltage Low ICM REFER to
Section 414
- 00 .
B1342 ECU Is Defective ICM REFER to
Section 413
- 01 .
B1356 Ignition Run Circuit Open ICM REFER to
Section 211
- 05 .
B1364 Ignition Start Circuit Open ICM REFER to
Section 211
- 05 .
B1600 PATS Ignition Key Transponder Signal Is Not Received —
Damaged Key or Non-
PATS Key ICM GO to
Pinpoint Test F .
B1601 PATS Received Incorrect Key-Code From Ignition Key
Transponder (Unprogrammed Encoded Ignition Key) ICM GO to
Pinpoint Test G .
B1602 PATS Received Invalid Format Of Key-
Code From Ignition
Key Transponder (Partial Key Read) ICM GO to
Pinpoint Test H .
B1681 PATS Transceiver Signal Is Not Received (Not
Connected, Damaged, or Wiring) ICM GO to
Pinpoint Test I . Klj . 2 ba
182003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

Pinpoint Tests
PINPOINT TEST A: NO COMMUNICATION WITH THE INSTRUMENT
CLUSTER DTCs are retrieved,
CHECK for other
possible causes.
z The anti- theft system
does not operate
correctly — the
vehicle starts but
flashes a fault code
on the theft indicator
at key on z
Incorrect PCM
calibration z
GO to Pinpoint Test C .
Test Step Result / Action to Take
A1 CHECK THE BATTERY POWER SUPPLY TO THE
INSTRUMENT CLUSTER z
Key in OFF position.
z Disconnect: Instrument Cluster C220b.
z Measure voltage between instrument cluster C220b Pin 10,
Circuit 729 (RD/WH), harness side and ground.
z Is the voltage greater than 10 volts? Yes
GO to
A2 .
No
REPAIR the circuit.
REPEAT the self- test.
CLEAR the DTCs. A2 CHECK THE RUN POWER SUPPLY TO THE INSTRUMENT
CLUSTER z
Key in ON position.
z Measure the voltage between instrument cluster C220b Pin 11,
Circuit 489 (PK/BK), harness side and ground.
z Is the voltage greater than 10 volts? Yes
GO to
A3 .
No
REPAIR the circuit.
REPEAT the self- test.
CLEAR the DTCs. A3 CHECK RUN/START POWER SUPPLY TO THE INSTRUMENT Klj . 4 ba
182003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

GENERAL PROCEDURES
Key Programming —
Program a Key Using Two
Programmed Keys
NOTE: This procedure only works if two or more programmed ignition keys are available and it is
desired to program additional key(s). If two keys are not available, follow the procedure in Key Programming — Erase All Key Codes and Program Two Keys .
NOTE: PID SPARE_KY must be enabled for this procedure to operate. If this Parameter Identification
(PID) Index is not enabled, follow the security access procedure and select Spare Key Programming
Switch: Enabled.
NOTE: If the programming procedure is successful, the new key(s) will start the vehicle and the
THEFT INDICATOR will illuminate for approximately three seconds.
NOTE: If the programming procedure is not successful, the new key(s) will not start the vehicle and the
THEFT INDICATOR will flash. If the programming procedure was not successful, repeat the key
programming procedure from Step 1. If the failure repeats, check Circuit 729 (RD/WH) (hot at all times)
in instrument cluster for proper battery voltage. Repair the circuit if voltage is not present. For
additional information, refer to Diagnosis and Testing to review diagnostic trouble codes (DTCs) and
perform pinpoint tests as required.
NOTE: A maximum of eight ignition keys can be programmed to a passive anti- theft system (PATS)
equipped vehicle. Use PID NUMKEYS to determine how many keys are programmed to the vehicle.
NOTE: If the steps are not performed as outlined, the programming procedure will end.
NOTE: Ignition keys must have correct mechanical key cut for the vehicle and must be a PATS
encoded key.
1. Insert the first programmed ignition key into the ignition lock cylinder and turn the ignition switch from OFF to RUN (maintain the ignition switch in RUN for one second).
2. Turn the ignition switch to OFF and remove the first key from the ignition lock cylinder.
3. Within five seconds of turning the ignition switch to OFF, insert the second programmed ignition key into the ignition lock cylinder and turn the ignition switch from OFF to RUN (maintain the
ignition switch in RUN for one second).
4. Turn the ignition switch to OFF and remove the second key from the ignition lock cylinder.
5. Within 10 seconds of turning the ignition lock cylinder to OFF, insert the unprogrammed ignition key (new key) into the ignition lock cylinder and turn the ignition switch from OFF to RUN
SECTION 419-
01: Anti-Theft — PATS 2003 Mustang Workshop Manual Special Tool(s)
Worldwide Diagnostic System
(WDS)
418-
F224,
New Generation STAR (NGS)
Tester
418- F052, or equivalent
diagnostic tool Klj . 1 ba
22003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...