Suzuki GRAND VITARA Owner's Manual page 238

1A-183 Engine General Information and Diagnosis:
Step
15 CAN communication line circuit ground short check
1) Measure resistance at following connector terminals.
• Between "E23-4" terminal of ECM connector and
vehicle body ground
• Between "E23-19" terminal of ECM connector and
vehicle body ground
• Between "G31-1" terminal of BCM connector and
vehicle body ground
• Between "G31-2" terminal of BCM connector and
vehicle body ground
• Between "G31-3" terminal of BCM connector and
vehicle body ground
• Between "G31-4" terminal of BCM connector and
vehicle body ground
Is each resistance infinity?
16 Check for short circuit of CAN communication line to
power circuit
1) Measure voltage at following connector terminals with
ignition switch turned ON.
• Between "E23-4" terminal of ECM connector and
vehicle body ground
• Between "E23-19" terminal of ECM connector and
vehicle body ground
• Between "G31-1" terminal of BCM connector and
vehicle body ground
• Between "G31-2" terminal of BCM connector and
vehicle body ground
• Between "G31-3" terminal of BCM connector and
vehicle body ground
• Between "G31-4" terminal of BCM connector and
vehicle body ground
Is each voltage 0 – 1 V?
17 Vehicle spec check
Is vehicle equipped with A/T?
18 DTC check in TCM (for A/T model)
1) Connect connectors to all control modules with ignition
switch turned OFF.
2) Check DTC P1778 in TCM (for A/T model).
Is it indicated?
19 Combination meter operation check
1) Check combination meter operation for seat belt warning
lamp by fastening and unfastening driver side seat belt
with ignition switch turned ON.
Is it check result satisfactory?
Action Yes
Go to Step 16.
Go to Step 17.
Go to Step 18.
Go to Step 19.
Substitute a known-
good ECM and recheck.
No
Repair short to ground
of CAN communication
line circuit referring to
"Precaution for CAN
Communication
System: in Section 00".
Repair short to power
supply of CAN
communication line
circuit referring to
"Precaution for CAN
Communication
System: in Section 00".
Go to Step 19.
Substitute a known-
good ECM and recheck.
Substitute a known-
good BCM (included in
junction block
assembly) and recheck.