Subaru Legacy 2004 Service Manual page 2516

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
1 CHECK DTC.
2 CHECK BODY INTEGRATED UNIT.
1) Turn the ignition switch to OFF.
2) Connect the Subaru Select Monitor to data
link connector.
3) Turn the ignition switch to ON. (engine
OFF)
4) Turn the Subaru Select Monitor switch to
ON.
5) Read the data of brake pedal switch using
Subaru Select Monitor. <Ref. to 5AT(diag)-16,
OPERATION, Subaru Select Monitor.>
3 CHECK TCM.
Read the data of brake pedal switch using
Subaru Select Monitor. <Ref. to 5AT(diag)-16,
OPERATION, Subaru Select Monitor.>
4 CHECK BODY INTEGRATED UNIT INPUT
SIGNAL.
1) Disconnect the connector from body inte-
grated unit.
2) Measure the voltage between body inte-
grated unit connector and chassis ground.
Connector & terminal
(B281) No. 23 (+) — Chassis ground (
5 CHECK STOP LIGHT SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from stop light
switch.
3) Measure the resistance of harness
between stop light switch connectors.
Terminals
No. 1 — No. 2:
6 CHECK HARNESS CONNECTOR BETWEEN
BODY INTEGRATED UNIT AND STOP LIGHT
SWITCH.
1) Turn the ignition switch to ON.
2) Measure the voltage of harness between
the body integrated unit connector and chassis
ground.
Connector & terminal
(B281) No. 23 (+) — Chassis ground (
7 CHECK POOR CONTACT.
AUTOMATIC TRANSMISSION (DIAGNOSTICS)
Check
Is any of following DTC
detected?
' AT CAN Communication Cir-
cuit
' Output Speed Sensor Circuit
' AT Vehicle Speed Sensor
Circuit Malfunction (Rear
Wheel)
Is OFF displayed?
Is OFF displayed?
Is the voltage more than 10 V? Go to step 5.
$
):
Is the resistance more than 1
M"?
Is the voltage less than 1 V?
$
):
Is there poor contact in input
signal of brake switch?
5AT(diag)-57
Yes
Perform the diag- Go to step 2.
nosis according to
DTC.
Go to step 3. Go to step 4.
A temporary poor Replace the TCM
contact of connec- <Ref. to 5AT-61,
tor or harness may Transmission Con-
be the cause. trol Module
Check the poor (TCM).>
contact.
Go to step 7.
Go to step 6. Replace stop light
switch.
Go to step 7. Repair the short
circuit in harness
between TCM and
stop light switch.
Repair the poor Check the body
contact. integrated unit.
No