Subaru 2009 IMPREZA Service Manual page 3401

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
LAN SYSTEM (DIAGNOSTICS)
Step
1 CHECK DTC.
Read all DTCs using the Subaru Select Monitor.
<Ref. to LAN(diag)-15, READ DIAGNOSTIC
TROUBLE CODE (DTC), OPERATION, Subaru
Select Monitor.>
2 CHECK DTC.
Read the DTC of body integrated unit using
Subaru Select Monitor.
3 CHECK DTC.
1) Turn the ignition switch to OFF.
2) Disconnect all connectors (B280, B310 or
B301, B55, B136, B230, B231) that are con-
nected to high speed CAN communication line.
3) Connect the disconnected connectors.
4) Turn the ignition switch to ON.
5) Read the DTC of body integrated unit using
Subaru Select Monitor.
4 CHECK HARNESS.
1) Turn the ignition switch to OFF.
2) Disconnect all connectors (B280, B310 or
B301, B55, B136, B230, B231) that are con-
nected to high speed CAN communication line.
3) Using the tester, inspect the open circuit of
harness and short (power supply-output short,
GND-output short).
Connector & terminal
(B55) No. 17 — (B40) No. 14:
(B55) No. 18 — (B40) No. 6:
5 CHECK DTC.
1) Connect the disconnected connectors.
2) Start the engine.
3) Read the DTC of body integrated unit using
Subaru Select Monitor.
6 CHECK DTC.
Using the Subaru Select Monitor, read all
DTCs.
7 CHECK HARNESS.
1) Shake the harness used for CAN communi-
cation circuit.
2) Read the DTC of body integrated unit using
Subaru Select Monitor.
8 CHECK CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect all the connector that is con-
nected to high speed CAN circuit.
Check
Is there U1202, or any DTC
other than for the body inte-
grated unit?
Is U1222 a current malfunc-
tion?
Is U1222 a current malfunc-
tion?
Is harness normal?
Is U1222 a current malfunc-
tion?
Are DTCs P0600 or P0044,
P0045, C0140 displayed?
Is U1222 a current malfunc-
tion?
Is there poor contact of connec-
tor terminal?
LAN(diag)-68
Yes No
Perform the diag- Go to step 2.
nosis according to
DTC.
Go to step 3. Go to step 7.
Go to step 4. Go to step 7.
Go to step 5. Repair or replace
the harness.
Go to step 6. Go to step 7.
Replace the TCM. Replace the body
<Ref. to 4AT-63, integrated unit.
Transmission Con- <Ref. to SL-50,
trol Module REMOVAL, Body
(TCM).> Integrated Unit.>
Repair or replace Go to step 8.
the harness.
Repair the connec- Temporary poor
tor terminal where contact occurs.
poor contact
exists, or replace
harness.