2003 FORD MUSTANG check engine light

provide ventilation.
WARNING: When lifting a plastic- cased battery, excessive pressure on the end walls
could cause acid to spew through the vent caps resulting in personal injury, damage to the
vehicle or to the battery. Lift with a battery carrier or with your hands on opposite corners.
1. Verify the customer concern by operating the engine to duplicate the concern.
2. Inspect the charging system (battery, generator cable, harness connectors, connections) to determine if any obvious mechanical or electrical concerns exist. If found, repair as necessary
and test the system for normal operation. Refer to the following tables:
3. Check the operation of the charging system warning indicator lamp (instrument cluster). Normal operation is as follows:
zWith the ignition switch OFF, the charging system warning indicator should be OFF.
z With the ignition switch in RUN and the engine off, the charging system warning indicator
light should be on.
z With the engine running, the charging system warning indicator light should be off.
4. Verify the battery is being charged. Carry out the Battery— Load Test. Refer to Component
Tests in this section.
5. If the customer concern is verified after the initial inspection, refer to the Symptom Chart to determine which tests to carry out.
Symptom Chart Visual Inspection Chart
Mechanical Electrical
z
Battery case, posts, hold- down clamp, cables and
connections
z Generator drive (serpentine) belt for condition and
tension. Refer to Section 303 - 05 .
z Generator pulley z
Battery junction box (BJB)
fuse 20 (20A)
z Fuse links
z Circuitry
z Battery charge warning
indicator
z Cables
Normal Charging System Voltages Ignition
Switch
Position A Circuit
36
(YE/WH) I Circuit
904
(LG/RD) Generator B+
Circuit 38 (BK/OG) Battery Engine to
battery
ground Charging
System Warning Indicator
Operation OFF 12V 0V 12V 12V 0V Off
RUN-
engine off 12V 1-
3V 12V 12V 0V Illuminated
RUN-
engine
running 13-
15V 13-
15V 13-
15V 13-15V 0V Off Klj . 3 ba
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PINPOINT TEST H: RADIO INTERFERENCE
Component Tests
Battery—Load Test
1. With the engine running, turn the A/C on, the blower motor on high speed and the headlamps on high beam.
2. Increase the engine speed to approximately 2,000 rpm. The voltage should increase a minimum of 0.5 volt above the base voltage.
zIf the voltage does not increase as specified, carry out the Generator On- Vehicle Tests.
For additional information, refer to Generator On- Vehicle Tests in this section.
z If the voltage increases as specified, the charging system is operating normally. NOISE
z
Disconnect: Generator C102c (4.6L 4V) or
C102a (3.8L or 4.6L 2V).
z Key in START position.
z With the engine running, turn the headlights
on, rear defroster on, and the blower motor to
the HI position.
z Is the noise still present? Yes
GO to
G4 .
No
INSTALL a new generator. REFER to
Section 414 - 02 . TEST the system for
normal operation. G4 CHECK GENERATOR FOR MECHANICAL
NOISE z
Key in OFF position.
z Connect: Generator C102c (4.6L 4V) or C102a
(3.8L or 4.6L 2V).
z Key in START position.
z Turn all accessories off. With the engine
running, use a stethoscope or equivalent
listening device to probe the generator for
unusual mechanical noise.
z Is the generator the noise source? Yes
INSTALL a new generator. REFER to
Section 414
- 02 . TEST the system for
normal operation.
No
REFER to Section 303 - 00 to diagnose
the source of engine noise. Test Step Result / Action to Take
H1 VERIFY GENERATOR IS SOURCE OF
RADIO INTERFERENCE z
Key in START position.
z With the engine running, tune the radio to
a station where the interference is present.
z Key in OFF position.
z Disconnect: Generator C102c (4.6L 4V) or
C102a (3.8L or 4.6L 2V).
z Key in START position.
z With the engine running, note any radio
interference.
z Is the interference present with the
generator disconnected? Yes
REFER to
Section 415 - 00 for diagnosis and
testing of the in- vehicle entertainment
system.
No
INSTALL a new generator. REFER to
Section 414 - 02 . TEST the system for normal
operation. Klj . 10 ba
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Battery—
Drain Tests
NOTE: No production vehicle should have more than a 50 mA (0.050 amp) continuous draw.
Check for current drains on the battery in excess of 50 milliamps (0.050 amp) with all the electrical
accessories off and the vehicle at rest. Current drains can be tested with the following procedure:
WARNING: Do not attempt this test on a lead- acid battery that has recently been
recharged. Explosive gases can cause personal injury.
CAUTION: To prevent damage to the meter, do not crank the engine or operate
accessories that draw more than 10A.
NOTE: Many modules draw 10 mA (0.010 amp) or more continuously.
NOTE: Use an in- line ammeter between the battery positive or negative post and its respective cable.
NOTE: Typically, a drain of approximately one amp can be attributed to an engine compartment lamp,
glove compartment lamp, or luggage compartment lamp staying on continually. Other component
failures or wiring shorts may be located by selectively pulling fuses to pinpoint the location of the
current drain. When the current drain is found, the meter reading will fall to an acceptable level. If the
drain is still not located after checking all the fuses, it may be due to the generator.
NOTE: To accurately test the drain on a battery, an in- line digital ammeter must be used. Use of a test
lamp or voltmeter is not an accurate method due to the number of electronic modules.
1. Make sure the junction box/fuse panels are accessible without turning on interior and underhood lights.
2. Drive the vehicle at least five minutes and over 48 km/h (30 mph) to turn on and exercise vehicle systems.
3. Allow the vehicle to sit with the key off for at least 40 minutes to allow modules to time out/power down.
4. Connect a fused jumper wire between the negative battery cable and the negative battery post to prevent modules from resetting and to catch capacitive drains.
5. Disconnect the negative battery cable from the post without breaking the connection of the jumper wire.
6. NOTE: It is very important that continuity is not broken between the battery and the negative
battery cable when connecting the meter. If this happens, the entire procedure must be
repeated.
Connect the tester between the negative battery cable and the post. The meter must be capable
of reading milliamps and should have a 10 amp capability.
7. NOTE: If the meter settings need to be switched or the test leads need to be moved to another
jack, the jumper wire must be reinstalled to avoid breaking continuity.
Remove the jumper wire.
NOTE: Amperage draw will vary from vehicle to vehicle depending on the equipment package.
Compare to a comparable vehicle for reference.
NOTE: No production vehicle should have more than a 50 mA (0.050 amp) draw. Klj . 11 ba
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Component Tests
Grid Wire Test
1. Using a bright lamp inside the vehicle, inspect the wire grid from the exterior. A broken grid wire will appear as a brown spot.
2. Run the engine at idle. Set the rear window defrost switch to ON. The indicator light should come on.
3. Working from the interior of the vehicle with a voltmeter, contact the broad red- brown stripes of
the rear glass window positive lead to battery side and negative lead to ground side. The meter
should read 10- 13 volts. A lower voltage reading indicates a loose ground connection.
4. Contact a good ground point with the negative lead of the meter. The voltage reading should not differ.
5. With the negative lead of the meter grounded, touch each grid line of the heated rear window glass at its midpoint with the positive lead. A reading of approximately 6 volts indicates that the
line is good. A reading of zero volts indicates that the line is broken between the midpoint and
the B+ side of the grid line. A reading of 12 volts indicates that the circuit is broken between the
midpoint of the grid line and ground. z
Is the voltage greater than 10 volts? I4 CHECK THE ICM FOR CORRECT OPERATION
z
Disconnect all ICM connectors.
z Check for:
zcorrosion
z pushed- out pins
z Connect all ICM connectors and make sure they seat
correctly.
z Operate the system and verify the concern is still
present.
z Is the concern still present? Yes
INSTALL a new ICM. REFER
to Section 413
- 01 . CLEAR the
DTCs. REPEAT the self-test.
No
The system is operating
correctly at this time. Concern
may have been caused by a
loose or corroded connector.
CLEAR the DTCs. REPEAT
the self- test. Klj . 31 ba
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