Suzuki Wagon R Manual page 2662

DTC B3040 W-line Communication Fail for M13 Engine Model
Wiring Circuit
Refer to "Wiring Circuit for M13 Engine Model" on page 8G-2.
DTC Detecting Condition and Trouble Area
DTC Detecting Condition
No response from ECM while immobilizer control mod-
ule requests signal
Troubleshooting
Step
1 1) Ignition switch at OFF position.
2) Disconnect connector from ECM.
3) Check for proper connection to ECM at
E22-11 terminal.
Is it in good condition?
2 1) Ignition switch at OFF position.
2) Disconnect connector from immobilizer con-
trol module.
3) Check for proper connection to immobilizer
control module at G17-7 terminal.
Is it in good condition?
3 With connectors connected, measure voltage
between terminal G17-7 and ground with igni-
tion switch at ON position.
Is it 10 – 14 V?
4 With ignition switch at ON position, measure
voltage between E21-5 or E21-6 terminal and
ground.
Are they 10 – 14 V?
Action
IMMOBILIZER CONTROL SYSTEM (G10/M13 ENGINES) 8G-7
Trouble Area
W-line circuit
ECM power circuit
Yes
Go to step 2.
Go to step 3.
Go to step 4.
Substitute a known-good
ECM according to "Proce-
dure After ECM Replace-
ment" under "Registration
Procedure of Immobilizer
System Components",
and recheck.
No
Repair or replace.
Repair or replace.
W-line (WHT/BLK) circuit
open
ECM power supply (BLK/
WHT) circuit open