2003 FORD MUSTANG key

DIAGNOSIS AND TESTING
Keyless Entry
Refer to Wiring Diagrams Cell
59 , Generic Electronic Module for schematic and connector
information.
Refer to Wiring Diagrams Cell 111 , Remote Keyless Entry (RKE) for schematic and connector
information.
Principles of Operation
NOTE: Battery power and ground must be remove before disconnecting the GEM connectors to avoid
setting false codes.
Power Locks Operation
The power locks feature allows the customer to lock and unlock the doors via momentary switches
located on the driver and passenger door. When the GEM detects a momentary press of the driver or
passenger lock button, the GEM will supply power to the driver or passenger lock actuators for
approximately 250 ms from relays internal to the GEM. When the GEM detects a momentary press of
the driver or passenger unlock button, the GEM will supply power to the driver or passenger unlock
actuators for approximately 250 ms from relays internal to the GEM.
Remote Keyless Entry Door Locks Operation
The remote entry feature allows the customer to unlock the driver door, unlock all doors, and lock all
doors using a valid remote transmitter as long as the ignition switch is not in RUN or START. The
driver door is unlocked whenever the GEM detects a valid remote transmitter unlock transmission. All
the doors are unlocked when the GEM detects a second valid remote transmitter unlock transmission
within three seconds of the first transmission. All the doors are locked when the GEM detects a valid
remote transmitter lock transmission. If the GEM detects a second valid remote transmitter lock
transmission within three seconds of the first transmission, the doors will lock again, the horn will
sound for 20 ms and the parking lamps will flash for 200 ms to indicate the doors are locked. If the
GEM detects the driver or passenger door is ajar during the second lock transmission, the doors are
locked again and the horn is sounded twice. If the GEM detects a valid remote transmitter lock
transmission within three seconds of detecting a valid remote transmitter unlock transmission, the SECTION 501-
14B: Keyless Entry/Computer Operated Locks 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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GEM will lock all the doors.
Remote Keyless Entry Luggage Compartment Operation
The luggage compartment lid is released whenever the GEM detects a valid remote transmitter
luggage compartment release transmission.
Panic Alarm Operation
The panic alarm feature allows the vehicle to initiate an alarm for 2.75 minutes to identify itself using a
valid remote transmitter. The panic alarm is activated whenever the GEM detects the ignition switch is
in the OFF position or if the key is removed from the ignition, and the GEM detects a valid PANIC
response from the remote transmitter. When the panic alarm is activated, the GEM:
zilluminates the courtesy lamps.
z flashes the parking lamps.
z toggles the horn on and off.
The panic alarm is deactivated whenever GEM detects:
zif the key causes a transition of the ignition switch circuits to
„ACC.
„ RUN.
„ START.
z the remote transmitter
„panic button.
„ unlock button.
The panic alarm is also deactivated after 2.75 minutes have gone by.
Remote Transmitter Programming Operation
This feature allows the customer to program up to four different transmitter identification codes (TIC)
for four remote transmitters to the vehicle at any time. For additional information, refer to
Programming — Keyless Entry Remote Transmitter .
Inspection and Verification 1. The keyless entry system is a generic electronic module (GEM).
2. Verify the customer concern by using the remote transmitters to operate the keyless entry system.
3. Visually inspect for the following obvious signs of mechanical and electrical damage.
Visual Inspection Chart Klj . 2 ba
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Short to Ground
B1339 Chime Input Request Circuit
Short to Battery GEM REFER to
Section 413 - 09 .
B1340 Chime Input Request Circuit
Short to Ground GEM REFER to
Section 413 - 09 .
B1342 ECU Is Defective GEM CLEAR the DTC. Retrieve the DTCs. If DTC
B1342 is retrieved, INSTALL a new GEM. REFER to Section 419 - 10 .
B1353 Ignition Key-
In Circuit Open GEM REFER to
Section 413 - 09 .
B1359 Ignition Run/Acc Circuit Failure GEM REFER to
Section 211 - 05 .
B1396 Power Door Lock Circuit Short
to Battery GEM GO to
Pinpoint Test B .
B1397 Power Door Unlock Circuit
Short to Battery GEM GO to
Pinpoint Test B .
B1405 Driver Power Window Down
Circuit Short to Battery GEM REFER to
Section 501 - 11 .
B1408 Driver Power Window Up
Circuit Short to Battery GEM REFER to
Section 501 - 11 .
B1833 Door Unlock Disarm Switch
Circuit Short to Ground GEM REFER to
Section 419 - 01 .
B1498 Decklid Punch-Out Sensor
Ground Short. GEM GO to
Pinpoint Test D .
B1603 Lamp Anti-
Theft Indicator
Circuit Failure GEM REFER to
Section 413 - 01 .
B1410 Driver Power Window Motor
Circuit Failure GEM REFER to
Section 501 - 11 .
B1426 Lamp Safety Belt Circuit Short
to Battery GEM REFER to
Section 413 - 01 .
B1428 Lamp Safety Belt Circuit Failure GEM REFER to
Section 413 - 01 .
B1431 Wiper Brake/Run Relay Circuit
Failure GEM REFER to
Section 501 - 16 .
B1432 Wiper Brake/Run Relay Circuit
Short to Battery GEM REFER to
Section 501 - 16 .
B1434 Wiper Hi/Low Speed Relay Coil
Circuit Failure GEM REFER to
Section 501 - 16 .
B1436 Wiper Hi/Low Speed Relay Coil
Circuit Short to Battery GEM REFER to
Section 501 - 16 .
B1438 Wiper Mode Select Switch
Circuit Failure GEM REFER to
Section 501 - 16 .
B1441 Wiper Mode Select Switch
Circuit Short to Ground GEM REFER to
Section 501 - 16 .
B1446 Wiper Park Sense Circuit
Failure GEM REFER to
Section 501 - 16 .
B1448 Wiper Park Sense Circuit Short
to Battery GEM REFER to
Section 501 - 16 .
B1450 Wiper Wash/Delay Switch
Circuit Failure GEM REFER to
Section 501 - 16 .
B1453 Wiper Wash/Delay Switch
Circuit Short to Ground GEM REFER to
Section 501 - 16 . Klj . 4 ba
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Pinpoint Tests
PINPOINT TEST A: NO COMMUNICATION WITH THE GENERIC
ELECTRONIC MODULE z
Remote transmitter.
z Remote transmitter
batteries. Test C .
z The luggage compartment door
is inoperative using the remote
transmitter z
CJB Fuse 25 (25A).
z Remote transmitter
batteries.
z Remote transmitter.
z GEM.
z Circuitry.
z Luggage
compartment lid
release relay. z
GO to
Pinpoint Test D .
z Panic function does not operate
correctly z
GEM.
z Driver door unlock
relay.
z Circuitry.
z Remote transmitter
and batteries.
z Courtesy lamps.
z Horn relay.
z Horn.
z Parklamps. z
GO to
Pinpoint Test E .
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 CHECK THE 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 4 400 (LB/BK)
C201a 1 1006 (DG/WH)
C201b 2 1001 (WH/YE)
C201b 3 193 (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. Yes Klj . 6 ba
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PINPOINT TEST B: ALL DOOR LOCKS ARE INOPERATIVE z
Measure the reistance between the GEM C201b pin 4, circuit
397 (BK/WH), harness side and ground.
z Is the reistance less than 5 ohms? GO to
A3 .
No
REPAIR the circuit(s) in
question. TEST the system
for normal operation. A3 CHECK CIRCUIT 397 (BK/WH) FOR SHORT TO POWER
z
Measure the voltage between the GEM C201b pin 4, 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 POWER LOCK INPUTS TO THE GEM
z
Connect the diagnostic tool.
z Monitor the GEM PIDS DR_LOCK, DR_UNLK, PD_LOCK,
PD_UNLK, while depressing the driver and passenger power door
lock and unlock switches.
z Do the PID values agree with the switch positions? Yes
GO to
B11 .
No
GO to B2 .
B2 ISOLATE BETWEEN THE DRIVER AND PASSENGER POWER
DOOR LOCK SWITCHES NOTE:
This PID may not be supported in the normal scan tool PID
list. It can be located in the Function test —"Transmitter Tic/Data".
When this test is activated, the appropriate results may be obtained
when pressing the keyfob buttons.
z Connect the diagnostic tool.
z Monitor the GEM PIDS DR_LOCK and DR_UNLK, while
depressing the driver power door lock and unlock switches.
z Do the PID values agree with the switch positions? Yes
GO to
B7 .
No
GO to B3 .
B3 CHECK CIRCUIT 326 (WH/VT) FOR VOLTAGE —
DRIVER SIDE z
Disconnect: Master Window/Door Lock Control Switch C508.
z Measure the voltage between master window/door lock control
switch C508 Pin 3, Circuit 326 (WH/VT), harness side and ground. Yes
GO to
B4 .
No Klj . 7 ba
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z
Is the voltage greater than 10 volts? REPAIR Circuit 326
(WH/VT). REPEAT
the self-
test. CLEAR
the DTCs. B4 CHECK THE DRIVER POWER DOOR LOCK SWITCH FOR
CORRECT OPERATION z
Carry out the master window/door lock control switch component
test. REFER to Wiring Diagrams Cell 149, Component Testing.
z Is the master window/door lock control switch OK? Yes
GO to
B5 .
No
INSTALL a new
master window/door
lock control switch.
REPEAT the self-
test. CLEAR the
DTCs. B5 CHECK CIRCUITS 129 (LG) AND 1014 (VT) FOR SHORT TO
POWER z
Key in OFF position.
z Disconnect: GEM C201c.
z Measure the voltage between GEM C201c Pin 20, Circuit 129 (LG),
harness side and ground; and between GEM C201c Pin 18, Circuit
1014 (VT), harness side and ground.
z Key in ON position.
z Measure the voltage between GEM C201c Pin 20, Circuit 129 (LG),
harness side and ground; and between GEM C201c Pin 18, Circuit
1014 (VT), harness side and ground.
z Key in OFF position.
z Are the voltages greater than 10 volts? Yes
REPAIR the circuit in
question. REPEAT
the self-
test. CLEAR
the DTCs.
No
GO to B6 . Klj . 8 ba
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z
Key in ON position.
z Measure the voltage between GEM C201c Pin 19, Circuit 119
(PK/YE), harness side and ground; and between GEM C201c Pin
17, Circuit 120 (PK/LG), harness side and ground.
z Key in OFF position.
z Are the voltages greater than 10 volts? B10 CHECK CIRCUITS 119 (PK/YE) AND 120 (PK/LG) FOR OPEN
z
Measure the resistance between passenger window/door lock
control switch C629 Pin 2, Circuit 119 (PK/YE), harness side and
GEM C201c Pin 19, Circuit 119 (PK/YE), harness side; and
between passenger window/door lock control switch C629 Pin 4,
Circuit 120 (PK/LG), harness side and GEM C201c Pin 17, Circuit
120 (PK/LG), harness side.
z Are the resistances less than 5 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 in
question. REPEAT
the self- test. CLEAR
the DTCs. B11 CHECK GEM CONTROL OF THE POWER DOOR LOCKS
z
Connect the diagnostic tool.
z Trigger the GEM active command LOCK, UNLOCK, DD UNLOCK,
and DD LOCK ON and OFF.
z Do the doors lock and unlock? Yes
INSTALL a new
GEM. For additional
information, REFER
to
Section 419 - 10 .
REPEAT the self-
test. CLEAR the
DTCs.
No
GO to B12 . Klj . 10 ba
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PINPOINT TEST C: THE DOORS DO NOT LOCK/UNLOCK USING
THE REMOTE TRANSMITTER z
Did the passenger door lock and unlock? B18 CHECK CIRCUITS 163 (RD/OG), 1015 (RD/WH), 117 (PK/BK),
AND 118 (PK/OG) FOR OPEN z
Disconnect: GEM C201c.
z Measure the resistance between passenger door lock actuator
C603 Pin 2, Circuit 1015 (RD/WH), harness side and GEM C201c
Pin 10, Circuit 117 (PK/BK), harness side; and between passenger
door lock actuator C603 Pin 1, Circuit 163 (RD/OG), harness side,
and GEM C201c Pin 8, Circuit 118 (PK/OG), harness side.
z Are the resistances less than 5 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 in
question. REPEAT
the self- test. CLEAR
the DTCs. Test Step Result / Action to Take
C1 CHECK THE LOCK OPERATION USING
THE DRIVER DOOR LOCK SWITCH z
Lock and unlock the doors using the
driver door lock switch.
z Do all the doors lock and unlock
correctly? Yes
GO to
C2 .
No
GO to Pinpoint Test B .
C2 CHECK IGNITION STATES
z
Connect the diagnostic tool.
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 THE GEM FUNCTION TEST
TIC/DATA NOTE:
This PID may not be supported in Yes Klj . 13 ba
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