Suzuki Wagon R Manual page 928

DTC B3040 W-LINE COMMUNICATION FAIL
WIRING CIRCUIT
DTC DETECTING CONDITION AND TROUBLE AREA
DTC DETECTING CONDITION
No response from ECM while immobilizer control
module requests signal.
TROUBLE SHOOTING (DTC B3040)
STEP
1 1) Ignition switch at OFF position.
2) Disconnect connector from ECM.
3) Check for proper connection to ECM at E22-3
terminal.
Is it in good condition?
2 1) Ignition switch at OFF position.
2) Disconnect connector from immobilizer control
module.
3) Check for proper connection to immobilizer
control module at G19-7 terminal.
Is it in good condition?
3 With connectors connected, measure voltage
between terminal G19-7 and ground with ignition
switch at ON position.
Is it 10 – 14 V?
4 With ignition switch at ON position, measure
voltage between E22-5 or E22-6 and ground.
Are they 10 – 14 V?
ACTION
IMMOBILIZER CONTROL SYSTEM 8G-13
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
PROCEDRE FOR
ECM REPLACEMENT
and recheck.
1. ECM
2. Immobilizer control module
3. Main relay
NO
Repair or replace.
Repair or replace.
W-line (W/B) circuit
open.
ECM power supply
(B/R) circuit open.