2003 FORD MUSTANG check engine

*
PCM output driver EPC solenoid is
checked. An error
will be noted if
tolerance is
exceeded. maximum EPC
pressure, harsh
engagements and
shifts. Test D .
P1747
* EPC, wiring,
PCM EPC solenoid
circuit failure,
shorted circuit
or output
driver Voltage through
EPC solenoid is
checked. An error
will be noted if
tolerance is
exceeded. Short circuit causes
minimum EPC
pressure (minimum
capacity) and limits
engine torque
(alternate firm). Go To Pinpoint
Test D .
P1760 EPC, wiring,
PCM EPC solenoid
circuit failure,
shorted circuit
or output
driver PCM detected a
loss of EPC during
operation. Unexpected
reduction in engine
torque. Go To Pinpoint
Test D .
P0750
a SSA, wiring,
PCM SSA solenoid
circuit failure SSA circuit failed
to provide voltage
drop across
solenoid. Circuit
open or shorted or
PCM driver failure
during on-
board
diagnostic. Incorrect gear
selection depending
on condition mode
and manual lever
position. See
Solenoid On/Off
Chart. Go To Pinpoint
Test A .
P0753 SSA, wiring,
PCM SSA electrical
circuit failure SSA circuit fails to
provide voltage
drop across
solenoid. Circuit
open or shorted or
PCM driver failure
during on-
board
diagnostic. Incorrect gear
depending on
condition mode and
manual lever
position. See
Solenoid Off/On
Chart. Flashing
Transmission
Control Indicator
Lamp (TCIL). Go To Pinpoint
Test A .
P0751 SSA, wiring,
PCM Shift solenoid
A functional
failure Mechanical or
hydraulic failure of
the shift solenoid. Incorrect gear
selection depending
on failure mode
manual lever
position. REFER to Solenoid
Operation Chart.
Go To Pinpoint
Test A .
P0781
b SSA or
internal parts 1-
2 shift error Engine rpm drop
not detected when
1-
2 shift was
commanded by
PCM. Incorrect gear
selection depending
on failure or mode
and manual lever
position. Shift errors
may also be due to
other internal
transmission
concerns (stuck
valves, damaged
friction material). REFER to Solenoid
Operation Chart.
Go To Pinpoint
Test A .
P1714 SSA,
internal
components SSA
malfunction Mechanical failure
of the solenoid
detected. Incorrect gear
selection depending
on condition, mode
and manual lever
position. See
Solenoid Operation
Chart. Go To Pinpoint
Test F .
P0755
a SSB, wiring,
PCM SSB solenoid
circuit failure SSB circuit fails to
provide voltage Incorrect gear
selection depending Go To Pinpoint
Test A . Klj . 4 ba
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a
Output circuit check, generated only by electrical symptoms.
b May also be generated by some other non- electric transmission hardware system.
Rotunda Transmission Tester
The Transmission Tester is used to diagnosis the digital transmission range sensor and is used in
conjunction with the pinpoint tests. The tests should be carried out in order. Installing the Transmission
Tester allows separation of the vehicle electronics from transmission electronics; refer to the
Transmission Tester manual for these tests.
zDigital Transmission Range (TR) Sensor Testing components converter
clutch
engagement
error (engine speed
surge) across the
torque converter
clutch. present in 3rd gear.
P1742 TCC,
internal
components TCC solenoid
failed ON TCC solenoid has
failed on by
electric,
mechanical or
hydraulic concern. Harsh shifts. Go To Pinpoint
Test A .
P1743 TCC,
internal
components TCC solenoid
failed ON TCC solenoid has
failed ON by
electric,
mechanical or
hydraulic concern. Harsh shifts. Go To Pinpoint
Test A .
P1744 TCC TCC The PCM picked
up an excessive
amount of TCC
slippage during
normal vehicle
operation. TCC
slippage/erratic or
no torque converter
clutch operation. GO to Diagnosis by
Symptom.
P1767 TCC TCC solenoid
circuit failure
during OBD
Test TCC solenoid
circuit fails to
provide voltage
drop across
solenoid. Circuit
open or shorted or
PCM Driver failure
during OBD Test. Short circuit: engine
stalls in second
(O/D, 2 range) at
low idle speeds with
brake applied.
Open circuit:
Torque Converter
never engages. Go To Pinpoint
Test A .
P1780 TCS TCS not
changing
states TCS not cycled
during self-
test.
TCS circuit open
or shorted. Rerun on-
board
diagnostic and
cycle switch. No
OD cancel when
switch is cycled. REFER to the
Powertrain
Control/Emissions
Diagnosis (PC/ED)
manual.
— TCIL TCIL circuit
failure TCIL circuit open
or shorted. Failed on, OD
cancel mode on. No
flashing TCIL for
EPC failure or
sensor. Failed off,
OD cancel mode
never indicated. No
flashing TCIL for
EPC sensor failure. REFER to the
Powertrain
Control/Emissions
Diagnosis (PC/ED)
manual
P1709 PNP switch PNP switch
out of self-
test
range Vehicle not in
PARK or
NEUTRAL during
on-
board
diagnostic. Rerun on-
board
diagnostic in PARK
or NEUTRAL. Go To Pinpoint
Test C . Klj . 7 ba
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z
Measure the resistance for each solenoid (SSA, SSB or
TCC) as follows:
z Are the resistances correct? Solenoid Resistance (ohms)
SSA 20-
30 SSB 20-
30 TCC 10-
16 A9 CHECK SOLENOID FOR SHORT TO GROUND
z
Check for continuity between engine ground and
appropriate solenoid pin with ohmmeter or other low
current tester. Connection should show infinite
resistance (no continuity).
z Is there continuity? Solenoid Terminal
SSA +/-
SSB +/-
TCC +/- Yes
INSTALL a new solenoid.
No
REFER to
Diagnosis By Symptom in this section for
diagnosis of shift or torque
converter concerns. Klj . 7 ba
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harness is wiggled, the sensor is tapped, or the
vehicle driven?
C6 CHECK DIGITAL TRANSMISSION RANGE SENSOR
OPERATION z
Disconnect: Digital TR Sensor .
z CAUTION: Do not pry on connector. This will
damage the connector and result in a transmission
concern.
z Connect: TR- E Cable to Transmission Tester.
z Connect: TR- E Cable to Digital TR Sensor.
z Place the Digital TR Overlay onto Transmission Tester.
z Carry out Sensor Test as instructed on the Digital TR
Overlay.
z Does the status lamp on the tester TRS- E cable
match the selected gear positions? Yes
Concern is not in the digital TR
sensor, GO to
C7 .
No
INSTALL a new digital TR
sensor. CLEAR DTCs and
REPEAT OBD Tests. C7 CHECK PCM HARNESS CIRCUITS FOR OPENS
z
Key in OFF position.
z Disconnect: Powertrain Control Module (PCM) .
z Inspect for damaged or pushed- out pins, corrosion or
loose wires.
z Disconnect: Digital TR Sensor.
z CAUTION: Do not pry the connector. This will
damage the connector and result in a transmission
concern.
z Disconnect the digital TR sensor connector.
z Install the EEC- V Control System Breakout Box.
z Measure the resistance between the PCM test pin 91 at
the EEC- V Control System Breakout Box and signal
return circuit pin 2 at digital TR sensor connector
harness side.
z For vehicles equipped with a 4.6L engine measure the
resistance between the PCM test pin 34 at the EEC- V
Control System Breakout Box and TR1 circuit pin 4 at
digital TR sensor connector harness side.
z For vehicles equipped with a 3.8L engine measure the
resistance between the PCM test pin 3 at the EEC- V Yes
GO to
C8 .
No
REPAIR open circuit(s).
RECONNECT all components.
CLEAR DTCs. REPEAT OBD
Tests. Klj . 11 ba
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97, 51, 77, 103, and 91 at the EEC-
V Control System
Breakout Box and chassis ground.
z Are all resistances greater than 10,000 ohms? C9 CHECK FOR SHORT BETWEEN TR/PCM INPUT
SIGNAL CIRCUITS z
For vehicles equipped with a 3.8L engine measure the
resistance between test pin 3 and pins 49, 50, and 64 at
the EEC- V Control System Breakout Box.
z For vehicles equipped with a 4.6L engine measure the
resistance between test pin 34 and pins 49, 50, and 64
at the EEC- V Control System Breakout Box.
z For vehicles equipped with a 3.8L engine measure the
resistance between test pin 49 and pins 3, 50, and 64 at
the EEC- V Control System Breakout Box.
z For vehicles equipped with a 4.6L engine measure the Yes
INSTALL a new PCM. REFER
to Section 303
- 14 .
RECONNECT all components.
CLEAR DTCs. REPEAT OBD
Tests.
No
REPAIR shorts on circuits
having less than 10,000 ohms
between other TR/PCM input
signal circuits. RECONNECT
all components. CLEAR DTCs.
REPEAT OBD Tests. Klj . 15 ba
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XXX.
z Press "SEND".
z Does the voltage and solenoid state change? D5 CHECK LEAD FRAME CONNECTIONS
z
Key in OFF position.
z Disconnect: Lead Frame.
z Inspect for damaged or pushed out pins, corrosion, etc.
z Using the special tool, check each of the lead frame
connector pins.
z Does the special tool go through the lead frame
connector pins? Yes
INSTALL a new lead frame.
GO to
D6 .
No
GO to D6 .
D6 CHECK SOLENOID RESISTANCE AT SOLENOID
z
Disconnect: Transmission Harness .
z Measure the resistance between the pins of the solenoid.
z Measure the resistance of the EPC solenoid.
z Is the resistance between 2.48 and 5.66 ohms? Yes
GO to
D7 .
No
INSTALL a new solenoid.
CLEAR the DTCs. REPEAT
the OBD Tests. D7 CHECK SOLENOID FOR SHORT TO GROUND
z
Check for continuity between engine GROUND and the
EPC solenoid terminals with ohmmeter or other low
current tester (less than 200 milliamps). Connection
should show infinite resistance (no continuity).
z Is there continuity? Yes
INSTALL a new solenoid.
CLEAR the DTCs. REPEAT
the OBD Tests.
No
REFER to
Diagnosis By Symptom in this section for
diagnosis of pressure
concerns. Klj . 19 ba
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PINPOINT TEST E: OUTPUT SHAFT SPEED (OSS) SENSORS
Test Step Result / Action to Take
NOTE:
Refer to the Output Shaft Speed (OSS) Sensor Harness Connector illustration preceding
these pinpoint tests. E1 ELECTRONIC DIAGNOSTICS
z
Check to make sure the transmission harness
connector is fully seated, pins are fully engaged in
connector and in good condition before proceeding.
z Connect the diagnostic tool.
z Key in ON position.
z Enter the following diagnostic mode on the diagnostic
tool: Diagnostic Data Link.
z Enter the following diagnostic mode on the diagnostic
tool: PCM.
z Select PID/Data Monitor and Record.
z Select the PID OSS.
z Does vehicle enter PID/Data Monitor and Record? Yes
GO to
E2 .
No
REPEAT procedure to ENTER
PID. If vehicle did not enter PID,
REFER to the Powertrain
Control/Emissions Diagnosis
(PC/ED) manual for diagnosis of
PCM. E2 DRIVE CYCLE TEST
z
While monitoring the OSS Speed PID, drive the
vehicle so that the transmission upshifts and
downshifts through all gears.
z Does the OSS Speed PID increase and decrease
with engine and vehicle speed? Yes
CLEAR all DTCs. ROAD TEST to
verify if concern is still present. If
concern is still present, REFER to
Diagnosis By Symptom
in this
section.
No
If the OSS Speed PID does not
increase and decrease with
engine and vehicle speed,
INSPECT for open or short in
vehicle harness, sensor, a PCM
concern, or internal hardware
concern.
If the sensor signal is erratic,
INSPECT for intermittent concern
in the internal/external harness,
sensor, or connector.
If the sensor signal is steady, GO
to E3 .
E3 CHECK RESISTANCE OF OSS SENSOR
z
Disconnect the vehicle harness connector from the
OSS sensor.
z Measure the resistance between the OSS sensor pins. Yes
REFER to
Diagnosis By Symptom for concern diagnosis.
No
INSTALL a new OSS sensor. Klj . 20 ba
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DIAGNOSIS AND TESTING
Special Testing Procedures
The special tests are designed to aid the technician in diagnosing the hydraulic and mechanical portion
of the transmission.
Engine Idle Speed Check
Refer to the Powertrain Control/Emissions Diagnosis (PC/ED) manual for diagnosis and testing of the
engine idle speed.
Line Pressure Test
CAUTION: Carry out the line pressure test prior to carrying out the stall speed test. If the
line pressure is low at stall, do not carry out stall speed test or further transmission damage
will occur. Do not maintain WOT in any transmission range for more than five seconds.
This test verifies that the line pressure is within specification.
1. Connect pressure gauge to line pressure tap.
SECTION 307-
01: Automatic Transaxle/Transmission 2003 Mustang Workshop Manual Item Part Number Description
1 — Direct clutch pressure tap
2 — Forward clutch pressure tap
3 — Electronic pressure control (EPC) pressure tap
4 — Intermediate clutch pressure tap
5 — Line pressure tap Klj . 1 ba
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