2004 SUBARU FORESTER light

4AT(H4DOTC)-81
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
7 CHECK OUTPUT SIGNAL FROM TCM US-
ING SUBARU SELECT MONITOR.
1) Connect the connectors to TCM and trans-
mission.
2) Lift-up the vehicle and place rigid racks.
N
OTE:
Raise all wheels off ground.
3) Connect the Subaru Select Monitor to data
link connector.
4) Start the engine and turn Subaru Select
Monitor switch to ON.
5) Start the engine and warm-up the engine
until ATF temperature is above 80°C (176°F).
N
OTE:
If ambient temperature is below 0°C (32°F),
drive the vehicle until ATF reaches its operating
temperature.
6) Read the data of high clutch duty solenoid
using Subaru Select Monitor.
 High clutch duty solenoid is indicated in “%”.
7) Shift the select lever to “D” range and
slowly increase vehicle speed and measure at
3rd or 4th gear.
NOTE:
The speed difference between front and rear
wheels may light the ABS warning light, but this
indicates no malfunction. When AT control diag-
nosis is finished, perform the ABS memory
clearance procedure of on-board diagnostics
system. Mode.>Is the value 0%? Go to step 8.Go to step 9.
8 CHECK OUTPUT SIGNAL FROM TCM US-
ING SUBARU SELECT MONITOR.
Return the engine to idling speed and shift
select lever to “N” range.
N
OTE:
The speed difference between front and rear
wheels may light the ABS warning light, but this
indicates no malfunction. When AT control diag-
nosis is finished, perform the ABS memory
clearance procedure of on-board diagnostics
system. Mode.>Is the value 100%? Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. A tempo-
rary poor contact of
the connector or
harness may be the
cause. Repair the
harness or connec-
tor in TCM and
transmission.Go to step 9.
9 CHECK POOR CONTACT.Is there poor contact in high
clutch duty circuit?Repair poor con-
tact.Replace the TCM.
Transmission Con-
trol Module
(TCM).> Step Check Yes No

4AT(H4DOTC)-82
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
10 CHECK HIGH CLUTCH DUTY SOLENOID (IN
TRANSMISSION).
1) Remove the transmission connector from
bracket.
2) Drain the ATF.
CAUTION:
Do not drain the ATF until it cools down.
3) Remove the oil pan and disconnect con-
nector from high clutch duty solenoid.
4) Measure the resistance between high
clutch duty solenoid connector and transmis-
sion ground.
Connector & terminal
(AT12) No. 3 — Transmission ground:Is the resistance 2.0 — 4.5 Ω? Go to step 11.Replace the control
valve body. 4AT-61, Control
Valve Body.>
11 CHECK HARNESS CONNECTOR BETWEEN
HIGH CLUTCH DUTY SOLENOID AND
TRANSMISSION.
Measure the resistance of harness between
high clutch duty solenoid and transmission
connector.
Connector & terminal
(T4) No. 7 — (AT12) No. 3:Is the resistance less than 1
Ω?Go to step 12.Repair the open
circuit in harness
between TCM and
transmission con-
nector.
12 CHECK HARNESS CONNECTOR BETWEEN
HIGH CLUTCH DUTY SOLENOID AND
TRANSMISSION.
Measure the resistance of harness between
transmission connector and transmission
ground.
Connector & terminal
(T4) No. 7 — Transmission ground:Is the resistance more than 1
MΩ?Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. A tempo-
rary poor contact of
the connector or
harness may be the
cause. Repair the
harness or connec-
tor in high clutch
duty solenoid and
transmission.Repair the short
circuit in harness
between high
clutch duty sole-
noid and transmis-
sion connector. Step Check Yes No

4AT(H4DOTC)-84
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
5 CHECK OUTPUT SIGNAL FROM TCM.
1) Connect all connectors.
2) Start the engine and warm-up the engine
until ATF temperature is above 80°C (176°F).
N
OTE:
If ambient temperature is below 0°C (32°F),
drive the vehicle until ATF reaches its operating
temperature.
3) Turn the ignition switch to ON (engine
OFF).
4) Shift the select lever to “N” range.
5) Measure the voltage between TCM con-
nector and chassis ground.
Connector & terminal
(B56) No. 7 (+) — Chassis ground (
−):Is the voltage more than 10.5
V?Go to step 6.Go to step 9.
6 CHECK OUTPUT SIGNAL FROM TCM.
1) Shift the select lever to “1” range.
2) Measure the voltage between TCM con-
nector and chassis ground.
Connector & terminal
(B56) No. 7 (+) — Chassis ground (
−):Is the voltage less than 5 — 9
V? Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. A tempo-
rary poor contact of
the connector or
harness may be the
cause. Repair the
harness or connec-
tor in TCM and
transmission.Go to step 9.
7 CHECK OUTPUT SIGNAL FROM TCM US-
ING SUBARU SELECT MONITOR.
1) Connect all connectors.
2) Connect the Subaru Select Monitor to data
link connector.
3) Start the engine and turn Subaru Select
Monitor switch to ON.
4) Warm-up the transmission until ATF tem-
perature is above 80°C (176°F).
N
OTE:
If ambient temperature is below 0°C (32°F),
drive the vehicle until ATF reaches its operating
temperature.
5) Stop the engine and turn ignition switch to
ON (engine OFF).
6) Move the select lever to “N” range.
7) Read the data of low & reverse duty sole-
noid using Subaru Select Monitor.
 Low & reverse brake duty solenoid is indi-
cated in “%”.Is the value 100%? Go to step 8.Go to step 9. Step Check Yes No

4AT(H4DOTC)-85
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
8 CHECK OUTPUT SIGNAL FROM TCM US-
ING SUBARU SELECT MONITOR.
1) Shift the select lever to “1” range.
2) Read the data of low & reverse duty sole-
noid.Is the value 61.5%? Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. A tempo-
rary poor contact of
the connector or
harness may be the
cause. Repair the
harness or connec-
tor in TCM and
transmission.Go to step 9.
9 CHECK POOR CONTACT.Is there poor contact in low &
reverse duty solenoid circuit?Repair the poor
contact.Replace the TCM.
Transmission Con-
trol Module
(TCM).>
10 CHECK LOW & REVERSE BRAKE DUTY
SOLENOID (IN TRANSMISSION).
1) Remove the transmission connector from
bracket.
2) Drain the ATF.
CAUTION:
Do not drain the ATF until it cools down.
3) Remove the oil pan, and disconnect con-
nector from low & reverse brake duty solenoid.
4) Measure the resistance between low &
reverse brake duty solenoid connector and
transmission ground.
Connector & terminal
(AT12) No. 1 — Transmission ground:Is the resistance 2.0 — 4.5 Ω? Go to step 11.Replace the control
valve body. 4AT-61, Control
Valve Body.>
11 CHECK HARNESS CONNECTOR BETWEEN
TRANSMISSION AND LOW & REVERSE
BRAKE DUTY SOLENOID.
Measure the resistance of harness between
low & reverse brake duty solenoid and trans-
mission connector.
Connector & terminal
(T4) No. 6 — (AT12) No. 1:Is the resistance less than 1
Ω?Go to step 12.Repair the open
circuit in harness
between low &
reverse brake duty
solenoid and
transmission con-
nector.
12 CHECK HARNESS CONNECTOR BETWEEN
TRANSMISSION AND LOW & REVERSE
BRAKE DUTY SOLENOID.
Measure the resistance of harness between
transmission connector and transmission
ground.
Connector & terminal
(T4) No. 6 — Transmission ground:Is the resistance more than 1
MΩ?Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. A tempo-
rary poor contact of
the connector or
harness may be the
cause. Repair the
harness or connec-
tor in low & reverse
brake duty solenoid
and transmission.Repair the short
circuit in harness
between low &
reverse brake duty
solenoid and
transmission con-
nector. Step Check Yes No

4AT(H4DOTC)-87
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
2 CHECK HARNESS CONNECTOR BETWEEN
TCM AND N–R LOCK SOLENOID.
Measure the resistance of harness between
TCM and chassis ground.
Connector & terminal
(B56) No. 18 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 3.Repair the short
circuit in harness
between TCM and
N–R lock solenoid
connector.
3 CHECK HARNESS CONNECTOR BETWEEN
N–R LOCK SOLENOID AND CHASSIS
GROUND.
Measure the resistance of harness between
N–R lock solenoid and chassis ground.
Connector & terminal
(B117) No. 5 — Chassis ground:Is the resistance less than 1
Ω?Go to step 4.Repair the open
circuit in harness
between chassis
ground terminal
and N–R lock sole-
noid connector.
4 CHECK N–R LOCK SOLENOID.
Measure the resistance between N–R lock
solenoid.
Connector & terminal
(B117) No. 5 — No. 4:Is the resistance 20 — 40 Ω? Go to step 5.Replace the N–R
lock solenoid.
5 CHECK TCM OUTPUT SIGNAL.
1) Connect all connectors.
2) Turn the ignition switch to ON.
3) Shift the select lever to “D” range.
4) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B56) No. 18 (+) — Chassis ground (
−):Is the voltage more than 10.5
V?Go to step 6.Go to step 7.
6 CHECK OUTPUT SIGNAL FROM TCM.
1) Lift-up the vehicle and place rigid racks.
N
OTE:
Raise all wheels off ground.
2) Start the engine.
3) Shift the select lever “D” range and slowly
increase vehicle speed to 20 km/h (12 MPH).
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.
4) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B56) No. 18 (+) — Chassis ground (
−):Is the voltage less than 1 V? Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. A tempo-
rary poor contact of
the connector or
harness may be
cause. Repair the
harness or connec-
tor in reverse inhibi-
tor control circuit.Go to step 7.
7 CHECK POOR CONTACT.Is there poor contact in the
reverse inhibitor control circuit?Repair the poor
contact.Replace the TCM.
Transmission Con-
trol Module
(TCM).> Step Check Yes No

4AT(H4DOTC)-90
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
8 CHECK INPUT SIGNAL FOR TCM.
1) Connect the connectors to TCM and trans-
mission.
2) Lift-up the vehicle and place rigid racks.
N
OTE:
Raise all wheels off ground.
3) Start the engine and set vehicle in 20 km/h
(12 MPH) condition.
N
OTE:
The speed difference between front and rear
wheels may light the ABS warning light, but this
indicates no malfunction. When AT control diag-
nosis is finished, perform the ABS memory
clearance procedure of on-board diagnostics
system. Mode.>
4) Measure the AC voltage between TCM
connector terminals.
Connector & terminal
(B55) No. 24 (+) — No. 23 (
−):Is the voltage more than AC 2
V?Go to step 10.Replace the rear
vehicle speed sen-
sor.
9 CHECK INPUT SIGNAL FOR TCM USING
OSCILLOSCOPE.
1) Connect the connectors to TCM and trans-
mission.
2) Lift-up the vehicle and place rigid racks.
NOTE:
Raise all wheels off ground.
3) Set the oscilloscope to TCM connector ter-
minals.
Connector & terminal
Positive probe; (B55) No. 24:
Earth lead; (B55) No. 23:
4) Start the engine and set vehicle in 20 km/h
(12 MPH) condition.
NOTE:
The speed difference between front and rear
wheels may light the ABS warning light, but this
indicates no malfunction. When AT control diag-
nosis is finished, perform the ABS memory
clearance procedure of on-board diagnostics
system. Mode.>
5) Measure the signal voltage indicated on
oscilloscope.Is the voltage more than AC 2
V?Go to step 10.Replace the rear
vehicle speed sen-
sor.
10 CHECK POOR CONTACT.Is there poor contact in rear
vehicle speed sensor circuit?Repair the poor
contact.Replace the TCM.
Transmission Con-
trol Module
(TCM).> Step Check Yes No

4AT(H4DOTC)-92
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
5 CHECK OUTPUT SIGNAL FROM TCM.
1) Connect the connectors to TCM and trans-
mission.
2) Turn the ignition switch to ON (engine OFF).
3) Shift the select lever to “P” range.
4) Throttle is fully closed.
5) Measure the voltage between TCM con-
nector and chassis ground.
Connector & terminal
(B56) No. 4 (+) — Chassis ground (
−):Is the voltage less than 1 V? Go to step 6.Go to step 9.
6 CHECK OUTPUT SIGNAL FROM TCM.
1) Shift the select lever to “D” range.
2) Measure the voltage between TCM con-
nector and chassis ground with throttle fully
open.
Connector & terminal
(B56) No. 4 (+) — Chassis ground (
−):Is the voltage more than 10.5
V?Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. A tempo-
rary poor contact of
the connector or
harness may be the
cause. Repair the
harness or connec-
tor in TCM and
transmission.Go to step 9.
7 CHECK OUTPUT SIGNAL FROM TCM US-
ING SUBARU SELECT MONITOR.
1) Connect the connectors to TCM and trans-
mission.
2) Connect the Subaru Select Monitor to data
link connector.
3) Turn the ignition switch to ON (engine OFF)
and turn Subaru Select Monitor switch to ON.
4) Move the select lever to “N” range with
throttle fully close (vehicle speed 0 km/h (0
MPH)).
5) Read data of transfer duty solenoid using
Subaru Select Monitor.
 Transfer duty solenoid is indicated in “%”.Is the value 5%? Go to step 8.Go to step 9.
8 CHECK OUTPUT SIGNAL EMITTED FROM
TCM USING SUBARU SELECT MONITOR.
1) Shift the select lever to “D” range with throt-
tle fully open (vehicle speed 0 km/h (0 MPH)).
2) Read the data of transfer duty solenoid
using Subaru Select Monitor.
 Transfer duty solenoid is indicated in “%”.Is the value 90 — 95%? Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. A tempo-
rary poor contact of
the connector or
harness may be the
cause. Repair the
harness or connec-
tor in TCM and
transmission.Go to step 9.
9 CHECK POOR CONTACT.Is there poor contact in transfer
duty solenoid circuit?Repair the poor
contact.Replace the TCM.
Transmission Con-
trol Module
(TCM).> Step Check Yes No

4AT(H4DOTC)-93
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
10 CHECK TRANSFER DUTY SOLENOID (IN
TRANSMISSION).
1) Lift-up the vehicle and place rigid racks.
N
OTE:
Raise all wheels off ground.
2) Drain the ATF.
CAUTION:
Do not drain the ATF until it cools down.
3) Remove the extension case and disconnect
connector from transfer duty solenoid.
4) Measure the resistance between transfer
duty solenoid connector and transmission
ground.
Connector & terminal
(AT12) No. 5 — Transmission ground:Is the resistance 2.0 — 4.5 Ω? Go to step 11.Replace the con-
trol valve body.
Control Valve
Body.>
11 CHECK HARNESS CONNECTOR BETWEEN
TRANSFER DUTY SOLENOID AND TRANS-
MISSION.
Measure the resistance of harness between
transfer duty solenoid and transmission con-
nector.
Connector & terminal
(T4) No. 8 — (AT12) No. 5:Is the resistance less than 1
Ω?Go to step 12.Repair the open
circuit in harness
between transfer
duty solenoid and
transmission con-
nector.
12 CHECK HARNESS CONNECTOR BETWEEN
TRANSFER DUTY SOLENOID AND TRANS-
MISSION.
Measure the resistance of harness between
transmission connector and transmission
ground.
Connector & terminal
(T4) No. 8 — Transmission ground:Is the resistance more than 1
MΩ?Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. A tempo-
rary poor contact of
the connector or
harness may be the
cause. Repair the
harness or contact
in transfer duty
solenoid and trans-
mission.Repair the short
circuit in harness
between transfer
duty solenoid and
transmission con-
nector. Step Check Yes No