Suzuki GRAND VITARA Owner's Manual page 1662

10B-26 Body Electrical Control System:
DTC Detecting Condition and Trouble Area
DTC detecting condition
BCM can not receive CAN data from TCM (A/T
model) for longer than specified time
continuously.
DTC Confirmation Procedure
1) Connect scan tool to DLC with ignition switch turned OFF.
2) Turn ON ignition switch and clear DTC by using scan tool.
3) Start engine and run it for 1 min. or more.
4) Check DTC.
Troubleshooting
Step
1 Check DTC in BCM
Is DTC U1101 (No. 1101) and DTC U1073 (No. 1073)
detected together?
2 Check each control module connectors
1) Check connection of connectors of all control modules
communicating by means of CAN.
2) Recheck BCM for DTC.
Is DTC U1101 (No. 1101) detected?
3 CAN communication circuit check
1) Turn ignition switch to OFF position.
2) Disconnect connectors of BCM and TCM
communicating by means of CAN.
3) Check CAN communication circuit between control
modules for open, short and high resistance.
Is each CAN communication circuit in good condition?
4 DTC Check
1) Turn ignition switch to OFF position.
2) Connect connectors to BCM and TCM.
3) Check DTC for ECM.
Is DTC P1678 detected by ECM?
• CAN communication circuit
• BCM
• TCM (A/T model)
Action
Trouble area
Yes
Go to "DTC U1073 (No.
1073): Control Module
Communication Bus
Off: ".
Go to Step 3.
Go to Step 4.
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".
Repair circuit.
Check TCM power and
ground circuit. If circuit
is OK, substitute a
known-good TCM and
recheck.