Basic Diagnostic Procedure - Subaru LEGACY 2004 Service Manual

LAN SYSTEM (DIAGNOSTICS)

1. Basic Diagnostic Procedure

A: PROCEDURE
1. WITH SUBARU SELECT MONITOR
CAUTION:
• Subaru Select Monitor is required for reading DTC, performing diagnosis and reading current data.
• Remove foreign matter (dust, water and oil etc.) from the body integrated unit connector during re-
moval and installation.
• For the model with immobilizer, registration of immobilizer may be needed after the replacement of
controller and etc. For detail procedure, refer to "REGISTRATION MANUAL FOR IMMOBILIZER".
NOTE:
• To check harness for broken wires or short circuits, shake it while holding it or the connector.
• Check List for Interview <Ref. to LAN(diag)-3, Check List for Interview.>
Step
1 CHECK PRE-INSPECTION.
1) Ask the customer when and how the trou-
ble occurred using interview check list. <Ref. to
LAN(diag)-3, Check List for Interview.>
2) Check the display of freeze frame data.
(Combination meter, odo/trip meter)
2 BASIC INSPECTION.
Check the components which might affect
body control. <Ref. to LAN(diag)-5, INSPEC-
TION, General Description.>
3 CHECK INDICATION OF DTC.
1) Read the DTC. <Ref. to LAN(diag)-14,
READ DIAGNOSTIC TROUBLE CODE (DTC),
OPERATION, Subaru Select Monitor.>
NOTE:
If the communication function of the Subaru Se-
lect Monitor cannot be executed normally,
check the communication circuit. <Ref. to
LAN(diag)-30, COMMUNICATION FOR INI-
TIALIZING IMPOSSIBLE, Diagnostic Proce-
dure with Diagnostic Trouble Code (DTC).>
2) Record all DTCs and freeze frame data.
4 PERFORM THE GENERAL DIAGNOSTICS.
Inspect using "General Diagnostics Table".
<Ref. to LAN(diag)-79, General Diagnostic
Table.>
5 PERFORM THE DIAGNOSIS.
1) Fix the wrong part.
2) Perform the clear memory mode. <Ref. to
LAN(diag)-20, CLEAR MEMORY MODE,
OPERATION, Subaru Select Monitor.>
3) Read DTC. <Ref. to LAN(diag)-14, READ
DIAGNOSTIC TROUBLE CODE (DTC),
OPERATION, Subaru Select Monitor.>
Basic Diagnostic Procedure
Is freeze frame data dis-
played?
Is the component that might
influence the body control
problem normal?
Is DTC displayed?
Is result of inspection OK?
Is DTC displayed?
LAN(diag)-2
Check Yes
Go to step 3.
Go to step 3.
Go to step 5.
LAN system is nor-
mal.
Repeat step 5 until
DTC is not shown.
No
Go to step 2.
Repair or replace
each unit.
Go to step 4.
Go to step 5.
Finish the diagno-
sis.