Subaru Legacy (2005 year). Service manual — part 561

4AT(diag)-81

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

U: DTC P0801 REVERSE INHIBIT CONTROL CIRCUIT

DTC DETECTING CONDITION:
Shift lock solenoid malfunction, open or short reverse inhibitor control circuit
TROUBLE SYMPTOM:
• Gear is shifted from “N” range to “R” range during driving at 20 km/h (12 MPH) or more.
• Gear cannot be shifted from “N” range to “R” range.
WIRING DIAGRAM:

Step

Check

Yes

No

1

CHECK HARNESS CONNECTOR BETWEEN
TCM AND SHIFT LOCK SOLENOID.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from TCM and
shift lock solenoid.
3) Measure the resistance of harness
between TCM and shift lock solenoid connec-
tor.

Connector & terminal

(B55) No. 18 — (B116) No. 3:

Is the resistance less than 1
Ω?

Go to step 2.

Repair the open
circuit of harness
between TCM and
shift lock solenoid
connector.

AT-01893

TCM

18

B55

E

B116

B55

B116

3
4

1

2

7

8

9

5

6

3

4

10 11 12

19 20 21
29 30 31

13 14 15 16 17

27 28

18

22 23 24 25 26

2

3

6 7 8 9

1
5

4

10

BODY INTEGRATED MODULE

SHIFT LOCK
SOLENOID

4AT(diag)-82

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

2

CHECK HARNESS CONNECTOR BETWEEN
TCM AND SHIFT LOCK SOLENOID.
Measure the resistance of harness between
TCM and chassis ground.

Connector & terminal

(B55) No. 18 — Chassis ground:

Is the resistance more than 1
M

Ω?

Go to step 3.

Repair the short
circuit of harness
between TCM and
shift lock solenoid
connector.

3

CHECK HARNESS BETWEEN SHIFT LOCK
SOLENOID AND CHASSIS GROUND TERMI-
NAL.
Measure the resistance of harness between
shift lock solenoid and chassis ground.

Connector & terminal

(B116) No. 4 — Chassis ground:

Is the resistance less than 1
Ω?

Go to step 4.

Repair the open
circuit of harness
between chassis
ground and shift
lock solenoid con-
nector.

4

CHECK SHIFT LOCK SOLENOID.
Measure the resistance of shift lock solenoid
terminals.

Connector & terminal

(B116) No. 3 — No. 4:

Is the resistance 12 — 18

Ω?

Go to step 5.

Replace the shift
lock solenoid.

5

CHECK OUTPUT SIGNAL OF TCM.
1) Connect all the 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

(B55) No. 18 (+) — Chassis ground (

−

):

Is the voltage more than 10.5
V?

Go to step 6.

Go to step 7.

6

CHECK OUTPUT SIGNAL OF TCM.
1) Lift-up the vehicle.

NOTE:

Raise all wheels off floor.

2) Start the engine.
3) Shift the select lever to “D” range and
slowly increase vehicle speed to 20 km/h (12
MPH).

NOTE:

The speed difference between front and rear
wheels may light the ABS warning light or VDC
warning light, but this indicates no malfunction.
When AT control diagnosis is finished, perform
the ABS memory clearance procedure or VDC
memory clearance procedure of on-board diag-
nostics system. <Ref. to ABS(diag)-26, Clear
Memory Mode.> <Ref. to VDC(diag)-25, Clear
Memory Mode.>

4) Measure the voltage between TCM and
chassis ground.

Connector & terminal

(B55) No. 18 (+) — Chassis ground (

−

):

Is the voltage less than 1 V?

Even if the SPORT
indicator light is
blinking, the cir-
cuit has returned
to normal condi-
tion at this time. A
temporary poor
contact of connec-
tor or harness may
be the cause.
Repair the har-
ness or connector
in reverse inhibitor
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.
<Ref. to 4AT-66,
Transmission Con-
trol Module
(TCM).>

Step

Check

Yes

No

4AT(diag)-83

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

V: DTC P1706 AT VEHICLE SPEED SENSOR CIRCUIT MALFUNCTION (REAR

WHEEL)

DTC DETECTING CONDITION:
Input signal circuit of TCM is open or shorted.
TROUBLE SYMPTOM:
No lock-up or occurring tight corner braking phenomenon.
WIRING DIAGRAM:

AT-03161

23

24

B11

AT1

T4

9

17

13

3

1

2

B54

TCM

BATTERY

IGNITION
SWITCH

REAR VEHICLE
SPEED SENSOR

E

MAIN SBF

SBF-6

1 2 3

B11

AT1

1

2

3 4

5

6 7

8

9

13

14 15

20

19

17

16

10

11 12

18

B54

1 2

7

8 9

5

6

3

4

10 11 12
19 20 21

13 14 15 16

17 18

22 23 24

No.12

4AT(diag)-84

AUTOMATIC TRANSMISSION (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK IGNITION POWER SUPPLY CIR-
CUIT.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from rear vehicle
speed sensor.
Turn the ignition switch to ON.
3) Measure the ignition power supply voltage
between rear vehicle speed sensor connector
and transmission ground.

Connector & terminal

(AT1) No. 3 (+) — Transmission ground (

−

):

Is the voltage more than 10 V? Go to step 2.

Check harness
between rear vehi-
cle speed sensor
and battery for
open circuit, short
or poor contact.
Repair the har-
ness if required.

2

CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
1) Turn the ignition switch to OFF.
2) Measure the resistance of harness
between TCM connector and rear vehicle
speed sensor connector.

Connector & terminal

(B54) No. 23 — (AT1) No. 1:

Is the resistance less than 1
Ω?

Go to step 3.

Repair the open
circuit or poor con-
tact of connector in
harness between
TCM and rear
vehicle speed sen-
sor connector.

3

CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
Measure the resistance of harness between
TCM connector and rear vehicle speed sensor
connector.

Connector & terminal

(B54) No. 24 — (AT1) No. 2:

Is the resistance less than 1
Ω?

Go to step 4.

Repair the open
circuit or poor con-
tact of connector in
harness between
TCM and rear
vehicle speed sen-
sor connector.

4

CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
Measure the resistance of harness between
TCM connector and chassis ground.

Connector & terminal

(B54) No. 23 — Chassis ground:

Is the resistance more than 1
M

Ω?

Go to step 5.

Repair the short
circuit of harness
between TCM and
rear vehicle speed
sensor connector.

5

CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
Measure the resistance of harness between
TCM connector and chassis ground.

Connector & terminal

(B54) No. 24 — Chassis ground:

Is the resistance more than 1
M

Ω?

Go to step 6.

Repair the short
circuit of harness
between TCM and
rear vehicle speed
sensor connector.