Suzuki GRAND VITARA Owner's Manual page 236

1A-181 Engine General Information and Diagnosis:
Step
4 ECM, ABS hydraulic unit / control module and BCM
connector check
1) Check for proper connection at each ECM, ABS
hydraulic unit / control module and BCM connector
terminals with ignition switch turned OFF.
2) If connections are OK, recheck ECM for DTC with
engine running.
Is there DTC P1678?
5 ECM power and ground circuit check
1) Check ECM power and ground circuits referring to "ECM
Power and Ground Circuit Check: ".
Are they in good condition?
6 DTC check in BCM
1) Check DTC U1073 in BCM.
Is it indicated?
7 DTC check in ECM
1) Disconnect connector from BCM with ignition switch
turned OFF.
2) Check ECM for DTC(s).
Is there DTC P1678?
8 DTC check in ECM
1) Disconnect connectors from TCM (for A/T model) and
connect connector to ABS hydraulic unit / control module
with ignition switch turned OFF.
2) Check ECM for DTC.
Is there DTC P1678?
9 DTC check in ECM
1) Disconnect connector from keyless start control module
(if equipped) with ignition switch turned OFF.
2) Check ECM for DTC.
Is there DTC P1678?
10 DTC check in ECM
1) Disconnect connector from combination meter with
ignition switch turned OFF.
2) Check ECM for DTC.
Is there DTC P1678?
Action Yes
Go to Step 5.
Go to Step 6.
Go to "DTC U1073 (No.
1073): Control Module
Communication Bus
Off: in Section 10B".
Go to Step 8.
Go to Step 9.
Go to Step 10.
Go to Step 11.
No
Intermittent trouble.
Check for intermittent
referring to "Intermittent
and Poor Connection
Inspection: in Section
00".
Repair ECM power and/
or ground circuits.
Go to Step 7.
"G31-1" or "G31-3"
circuit wire between
BCM and CAN circuit
junction connector is
open or high resistance.
If wires are OK,
substitute a known-
good BCM and recheck.
"E92-17" or "E92-7"
circuit wire between
TCM and CAN circuit
junction connector is
open or high resistance.
If wires are OK,
substitute a known-
good TCM (for A/T
model) and recheck.
"G44-19" or "G44-18"
circuit wire between
keyless start control
module and CAN circuit
junction connector is
open or high resistance.
If wires are OK,
substitute a known-
good keyless start
control module and
recheck.
"G28-10" or "G28-8"
circuit wire between
combination meter and
CAN circuit junction
connector is open or
high resistance. If wires
are OK, substitute a
known-good
combination meter or
keyless start control
module (if equipped)
and recheck.