Dtc P1621: Immobilizer Communication Line Error - Suzuki GRAND VITARA Owner's Manual

Step
6 Check for short to ground wire circuit in CAN
communication wire circuits
1) Measure resistance at the following wire terminals.
• Between "E03-6" wire terminal at ABS connector and
body ground
• Between "E03-12" wire terminal at ABS connector
and body ground
Is resistance infinite?
7 Check for short to power supply wire circuit in CAN
communication wire circuits
1) Measure resistance at the following wire terminals with
the ignition switch at ON position.
• Between "E03-6" wire terminal at ABS connector and
body ground
• Between "E03-12" wire terminal at ABS connector
and body ground
Is voltage 0 V?
8 Check of keyless start control module power and
ground wire circuits
1) Check keyless start control module power and ground
wire circuits referring to "Keyless Start Control Module
Power and Ground Circuit Check: in Section 10E".
Are they in normal?

DTC P1621: Immobilizer Communication Line Error

Detecting Condition and Trouble Area
Detecting Condition
Communication error between immobilizer control module
(ICM) and ECM is detected by ECM.
Action
Immobilizer Control System:
Yes
Go to Step 7.
Go to Step 8.
Replace keyless start
control module with a
known-good one and
recheck.
Trouble Area
• Related fuse(s) blown
• Poor connection at immobilizer control module (ICM)
connector
• Poor connection at ECM connector
• Open in power supply wire circuit
• Open in ground wire circuit
• Open in communication wire circuits
• Short to ground wire circuit in communication wire
circuits
• Short to power supply wire circuit in communication
wire circuits
• Short of communication wire circuits
• Immobilizer control module (ICM) faulty
• ECM faulty
10C-15
No
Repair short to ground
wire circuit in CAN
communication wire
circuits.
Repair short to power
supply wire circuit in
CAN communication
wire circuits.
Repair malfunctional
wire circuit.
S5JB0AA304007