Suzuki Swift Sport 2004 Service & Repair Manual page 1426

10B-23 Body Electrical Control System:
DTC Troubleshooting
Step
1 DTC check of BCM
Is DTC U0155 (No. 0155) and DTC U1073 (No. 1073)
detected together?
2 Control module connector check
1) Check connection of connectors of all control modules
communicating by means of CAN.
2) Recheck BCM for DTC.
Is DTC U0155 (No. 0155) detected?
3 Combination meter power and ground circuit check
1) Turn ignition switch to ON position.
Do warning lights in combination meter other than key
indicator light light up?
4 CAN communication circuit check
1) Turn ignition switch to OFF position.
2) Disconnect connectors from BCM, combination meter
and steering angle sensor (ESP® model).
3) Check CAN communication circuit between BCM and
combination meter for open, short and high resistance.
Is each CAN communication circuit in good condition?
5 CAN communication circuit check
1) Disconnect connectors of all control modules
communicating by means of CAN.
2) Check CAN communication circuit between control
modules other than Step 4 for open, short and high
resistance.
Is each CAN communication circuit in good condition?
6 DTC check of BCM
1) Connect connectors of disconnected control modules
communicating by means of CAN.
2) Disconnect connector of any one of control module other
than BCM.
3) Recheck BCM for DTC.
Is DTC U0155 (No.0155) detected?
Action Yes
Go to "DTC U1073 (No.
1073): Control Module
Communication Bus
Off".
Go to Step 3.
Go to Step 4.
Go to Step 5.
Go to Step 6.
Disconnect connectors
of control modules other
than the one whose
connector is
disconnected in Step 2)
one by one and check
that DTC U0155 is
detected by BCM each
time connector is
disconnected. When
DTC U0155 is not
detected by BCM while
checking in this way, go
to description under
"NO" below. If DTC
U0155 is detected by
BCM even when
connectors of all control
modules that use CAN
communication with
BCM are disconnected,
substitute a known-
good BCM and recheck.
No
Go to Step 2.
Intermittent trouble.
Check for intermittent
referring to "Intermittent
and Poor Connection
Inspection in Section
00".
Check combination
meter power and
ground circuit. If circuit
is OK, substitute a
known-good
combination meter and
recheck.
Repair circuit.
Repair circuit.
Check power and
ground circuit of control
module disconnected in
Step 2). If circuit is OK,
substitute a known-
good control module
disconnected in Step 2)
and recheck.