Subaru 2009 IMPREZA Service Manual page 3403

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
Models with VDC
(B40) No. 6 — (B310) No. 35:
(B40) No. 14 — (B310) No. 10:
Models without VDC
(B40) No. 6 — (B301) No. 26:
(B40) No. 14 — (B301) No. 11:
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.
Read all DTCs using the Subaru Select Monitor.
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 connectors (B280, B310 or
B301, B55, B136, B230, B231) that are con-
nected to high speed CAN communication line.
Check
Is there DTC U1202?
Is U1223 a current malfunc-
tion?
Is U1223 a current malfunc-
tion?
Is harness normal?
Is U1223 a current malfunc-
tion?
Is P1718 or P0600 displayed? Replace the VDC/
Is U1223 a current malfunc-
tion?
Is there connector terminal
where poor contact exists?
LAN(diag)-70
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 body
ABS CM. <Ref. to integrated unit.
VDC-7, <Ref. to SL-50,
REMOVAL, VDC REMOVAL, Body
Control Module Integrated Unit.>
and Hydraulic Con-
trol Unit
(VDCCM&H/U).>
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.