Subaru IMPREZA 2002 Service Manual page 577

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE (DIAGNOSTICS)
B0:DTC PO734
-
GEAR 4 INCORRECT RATIO
-
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
TROUBLE SYMPTOM:
Shift point too high or too low; engine brake not effected in "3" range; excessive shift shock; excessive
tight corner "braking"
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(S0HC)-43, OP-
ERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(S0HC)-40, OPERATION, Inspec-
tion Mode.>.
WIRING DIAGRAM:
Step
I CHECK ANY OTHER DTC ON DISPLAY.
Check
Is there any other DTC on dis-
play?
Yes
Inspect relevant
DTC using "List of
Diagnostic Trou-
ble Code (DTC)".
<Ref. to
List of Diagnostic
Trouble Code
(DTC).>
Repair or replace
the throttle posi-
tion sensor circuit.
EN(S0HC)-77,
No
Go to step 2.
Go to step
3.
Repair or replace
the front vehicle
speed sensor cir-
cuit.
r
Go to step 4.
2 CHECK THROTTLE POSITION SENSOR
CIRCUIT.
Check throttle position sensor circuit. <Ref. to
SOR, Diagnostic Procedure with Diagnostic
Trouble Code (DTC).>
CHECK FRONT VEHICLE SPEED SENSOR
CIRCUIT.
Check front vehicle speed sensor circuit. <Ref.
SENSOR, Diagnostic Procedure with Diagnos-
tic Trouble Code (DTC).>
SPEED SENSOR CIRCUIT.
Check torque converter turbine speed sensor
circuit. <Ref. to AT-62, DTC 36 TORQUE CON-
VERTER TURBINE SPEED SENSOR, Diag-
nostic Procedure with Diagnostic Trouble Code
(DTC).>
Check poor contact in TCM connector.
AT-52, DTC 31 THROTTLE POSITION SEN-
3
to AT-57, DTC 33 FRONT VEHICLE SPEED
I CHECK TORQUE CONVERTER TURBINE
5 CHECK POOR CONTACT.
5 CHECK MECHANICAL TROUBLE.
Check mechanical trouble in automatic trans-
mission.
Is there any trouble in throttle
position sensor circuit?
Is there any trouble in front
vehicle speed sensor circuit?
Is there any trouble in torque
converter turbine speed sensor
circuit?
Is there poor contact in TCM
connector?
Is there any mechanical trouble
in automatic transmission?
EN(S0HC)-253
Repair or replace
the torque con-
verter turbine
speed sensor cir-
cuit.
Repair poor con-
tact in TCM con-
nector.
Repair or replace
the automatic
transmission.
<Ref. to AT-12,
INSPECTION,
Road Test.>
Go to step 5.
Go to step
6.
Replace the TCM.
<Ref. to AT-45,
Transmission Con
trol Module
(TCM).>