Subaru Impreza 2004 Service Manual page 157

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
BV:DTC P0734 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 effective 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(H4DOTC)(diag)-
47, OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4DOTC)(diag)-39, Inspec-
tion Mode.>.
• WIRING DIAGRAM:
Step
1 CHECK ANY OTHER DTC ON DISPLAY.
2 CHECK THROTTLE POSITION SENSOR
CIRCUIT.
Check the throttle position sensor circuit. <Ref.
to 4AT(diag)-47, DTC 31 THROTTLE POSI-
TION SENSOR, Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>
3 CHECK FRONT VEHICLE SPEED SENSOR
CIRCUIT.
Check the front vehicle speed sensor circuit.
<Ref. to 4AT(diag)-52, DTC 33 FRONT VEHI-
CLE SPEED SENSOR, Diagnostic Procedure
with Diagnostic Trouble Code (DTC).>
4 CHECK TORQUE CONVERTER TURBINE
SPEED SENSOR CIRCUIT.
Check the torque converter turbine speed sen-
sor circuit. <Ref. to 4AT(diag)-56, DTC 36
TORQUE CONVERTER TURBINE SPEED
SENSOR, Diagnostic Procedure with Diagnos-
tic Trouble Code (DTC).>
5 CHECK POOR CONTACT.
Check poor contact in TCM connector.
6 CHECK MECHANICAL TROUBLE.
Check mechanical trouble in automatic trans-
mission.
Check
Is any other DTC displayed?
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(H4DOTC)(diag)-236
Yes
Inspect the rele- Go to step 2.
vant DTC using
"List of Diagnostic
Trouble Code
(DTC)". <Ref. to
EN(H4DOTC)(dia
g)-74, List of Diag-
nostic Trouble
Code (DTC).>
Repair or replace Go to step 3.
the throttle posi-
tion sensor circuit.
Repair or replace Go to step 4.
the vehicle speed
sensor 2 circuit.
Repair or replace Go to step 5.
the torque con-
verter turbine
speed sensor cir-
cuit.
Repair the poor Go to step 6.
contact in TCM
connector.
Repair or replace Replace the TCM.
the automatic <Ref. to 4AT-74,
transmission. Transmission Con-
<Ref. to 4AT-34, trol Module
INSPECTION, (TCM).>
Road Test.>
No