Suzuki SWIFT RS415 2017, Service Manual

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10C-8 Immobilizer Control System:
DTC P1621 Immobilizer Communication Line Error
S4RS0AA304029
Possible Cause and Trouble Area
Troubleshooting
Possible Cause Trouble Area
• Temporary error
• Related fuse(s) blown
• Poor connection at immobilizer control module
connector
• “BLK/WHT” wire open
• “BLK/ORN” wire open
• “YEL/BLK” wire open, short to ground circuit, short to
power circuit, or shorted to “YEL/RED” wire
• “YEL/RED” wire open, short to ground circuit, short to
power circuit, or shorted to “YEL/BLK” wire
• Immobilizer control module faulty
• ECM faulty
• Related fuse(s)
• Connection at immobilizer control module
• “BLK/WHT” wire
• “BLK/ORN” wire
• “YEL/BLK” wire
• “YEL/RED” wire
• Immobilizer control module
• ECM
Step Action Yes No
1 Diagnostic Trouble Code (DTC) confirmation:
1) Clear DTC(s) referring to “Diagnostic Trouble Code
(DTC) Clearance: ”.
2) Turn the ignition switch to OFF position.
3) Check if any DTC is detected referring to “Diagnostic
Trouble Code (DTC) Check: ”.
Is DTC P1621 still detected?
Go to Step 2. The troubleshooting is
completed.
2 Fuse check:
1) Check if any related fuse is blown.
Is any fuse blown?
Replace blown fuse(s)
with new one (s). Go to Step 3.
3 Check for poor connection at immobilizer control
module:
1) Disconnect immobilizer control module connector “G24”
referring to “Immobilizer Control Module Removal and
Installation: ”.
2) Check if wire connections are normal at immobilizer
assembly connector “G24”.
Is each wire connection normal?
Go to Step 4. Repair poor
connection(s).
4 Check for poor connection at ECM:
1) Disconnect ECM connector “E23” referring to “Engine
Control Module (ECM) Removal and Installation: in
Section 1C”.
2) Check if wire connections at “E23-13” and “E23-28” wire
terminals are normal.
Is each wire connection normal?
Go to Step 5. Repair poor
connection(s).
5 Check for open in “BLK/WHT” wire:
1) Connect immobilizer control module connector “G24”
referring to “Immobilizer Control Module Removal and
Installation: ”.
2) With the ignition switch at ON position, check voltage
between “G24-1” wire terminal at immobilizer control
module and body ground.
Is voltage about 12 V?
Go to Step 6. Repair open in “BLK/
WHT” wire.