4AT(H4DOTC)-62
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
M: DTC P0736 REVERSE INCORRECT RATIO
DTC DETECTING CONDITION:
Vehicle speed sensor malfunction and torque converter turbine speed sensor malfunction, etc. or control
valve malfunction.
TROUBLE SYMPTOM:
Shift point is too high or too low.
Excessive shift shock.
Tight corner “braking” phenomenon.
Gear is not shifted to reverse.
Gear position is held by fail safe function.
Step Check Yes No
1 PREPARE SUBARU SELECT MONITOR.Do you have a Subaru Select
Monitor?Go to step 2.Go to step 5.
2 CHECK ACCELERATOR PEDAL POSITION
SENSOR.
1) Connect the Subaru Select Monitor to data
link connector.
2) Turn the ignition switch to ON.
3) Read the value of accelerator pedal posi-
tion sensor on Subaru Select Monitor.Does the value of accelerator
pedal position sensor change
from 0% to 100% smoothly
when throttle was operated from
fully closing to fully opening?Go to step 3.Check accelerator
pedal position sen-
sor.
4AT(H4DOTC)-94,
DTC P1708
THROTTLE POSI-
TION SENSOR
CIRCUIT LOW
INPUT, Diagnostic
Procedure with
Diagnostic Trou-
ble Code (DTC).>
3 CHECK FRONT VEHICLE SPEED SENSOR.
1) Lift-up the vehicle and place rigid racks.
2) Start the engine.
3) Move the select lever “D” range and slowly
increase vehicle speed.
NOTE:
The speed difference between front and rear
wheels may light ABS warning light, but this indi-
cates no malfunction. When AT control diagnosis
is finished, perform the ABS memory clearance
procedure of on-board diagnostics system.Does the vehicle speed dis-
played by Subaru Select Moni-
tor almost correspond with
vehicle speed indicated by
combination meter?Go to step 4.Check the front
vehicle speed sen-
sor.
4 CHECK TORQUE CONVERTER TURBINE
SPEED SENSOR.
1) Move the select lever to “P” or “N” range.
2) Idle the engine.Does the turbine speed sen-
sor revolution displayed by
Subaru Select Monitor almost
correspond with engine revolu-
tion indicated by tachometer?There are mal-
functions in TCM,
TCM connector
poor contact or
transmission
assembly mechan-
ical malfunction.Check the torque
converter turbine
speed sensor cir-
cuit.
5 CHECK ACCELERATOR PEDAL POSITION
SENSOR.
1) Turn the ignition switch to ON.
2) Fully close the throttle.
3) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B55) No. 19 (+) — Chassis ground (
−):Is the voltage 0.8 — 1.2 V? Go to step 6.Check the acceler-
ator pedal position
sensor circuit.
4AT(H4DOTC)-94,
DTC P1708
THROTTLE POSI-
TION SENSOR
CIRCUIT LOW
INPUT, Diagnostic
Procedure with
Diagnostic Trou-
ble Code (DTC).>
4AT(H4DOTC)-64
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
N: DTC P0741 TORQUE CONVERTER CLUTCH CIRCUIT PERFORMANCE OR
STUCK OFF
DTC DETECTING CONDITION:
Lock up clutch malfunction
Locking of valve
TROUBLE SYMPTOM:
Lock up is not operated.
Step Check Yes No
1 CHECK LOCK UP DUTY SOLENOID CIR-
CUIT.
Check according as DTC P0743 procedure.Is there malfunction? Repair or replace
the lock up duty
solenoid circuit.Go to step 2.
2 CHECK INHIBITOR SWITCH CIRCUIT.
Check according as DTC P0705 procedure.Is there malfunction? Repair or replace
the inhibitor switch
circuit.Go to step 3.
3 CHECK STOP LIGHT SWITCH CIRCUIT.
Check according as DTC P0719 and DTC
P0724 procedure.Is there malfunction? Repair or replace
the stop light
switch circuit.Go to step 4.
4 CHECK ATF TEMPERATURE SENSOR CIR-
CUIT.
Check according to DTC P0712 and DTC
P0713 procedure.Is there malfunction? Repair or replace
the ATF tempera-
ture sensor circuit.Go to step 5.
5 PREPARE SUBARU SELECT MONITOR.Do you have a Subaru Select
Monitor?Go to step 6.Go to step 9.
6 CHECK ACCELERATOR PEDAL POSITION
SENSOR.
1) Connect the Subaru Select Monitor to data
link connector.
2) Turn the ignition switch to ON.
3) Read the value of accelerator pedal posi-
tion sensor on Subaru Select Monitor display.Does the value of accelerator
pedal position sensor change
from 0% to 100% smoothly
when throttle was operated from
fully closing to fully opening?Go to step 7.Check the acceler-
ator pedal position
sensor circuit.
7 CHECK TORQUE CONVERTER TURBINE
SPEED SENSOR.
1) Move the select lever to “P” or “N” range.
2) Idle the engine.Does the turbine revolution dis-
played by Subaru Select Moni-
tor almost correspond with
engine revolution indicated by
tachometer?Go to step 8.Check the torque
converter turbine
speed sensor cir-
cuit.
8 CHECK ENGINE SPEED SIGNAL.
Idle the engine.Does the turbine revolution dis-
played by Subaru Select Moni-
tor almost correspond with
engine revolution indicated by
tachometer?There is malfunc-
tion in TCM, TCM
connector poor
contact or trans-
mission assembly
mechanical mal-
fuction.Check the engine
speed signal cir-
cuit.
9 CHECK ACCELERATOR PEDAL POSITION
SENSOR.
Check according to DTC P1708, DTC 1709
and DTC P1714 procedure.Is there a malfunction? Go to step 10.Repair or replace
the accelerator
pedal position sen-
sor circuit.
10 CHECK TORQUE CONVERTER TURBINE
SPEED SENSOR.
Check according to DTC P0715 procedure.Is there a malfunction? Go to step 11.Repair or replace
the torque converter
turbine speed sen-
sor circuit.
11 CHECK ENGINE SPEED SIGNAL.
Check according to DTC P0725 procedure.Is there a malfunction? Repair or replace
the engine speed
signal circuit. There is malfunc-
tion in TCM, TCM
connector poor
contact or trans-
mission assembly
mechanical mal-
function.
4AT(H4DOTC)-110
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AA:DTC P1718 CAN COMMUNICATION CIRCUIT
DTC DETECTING CONDITION:
Input signal circuit of TCM is open or shorted.
WIRING DIAGRAM:
Step Check Yes No
1 CHECK DTC.Are multiple DTCs displayed in
the on-board diagnostics test
mode?Go to other DTC. Go to step 2.
2 CHECK HARNESS CONNECTOR BETWEEN
TCM AND ECM.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from TCM and
ECM.
3) Measure the resistance of harness
between TCM and ECM connectors.
Connector & terminal
(B55) No. 3 — (B137) No. 18:Is the resistance less than 1
Ω?Go to step 3.Repair the open
circuit in harness
between TCM and
ECM or poor con-
tact of connector.
AT-01853
1832612
B55
B137
ECM
B55
TCM
B137
12
7
8956 3410 11 12
19 20 2113 14 15 16
17 1822
23
24
567
82 1
94 310
22 23 11 12 13 14 15
24 25
2616 17
18 19 20 21
27 28 29 30 31
TWISTED WIRE
