LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Suzuki >> 2009 >> SX4 LE, Standard >> Repair and Diagnosis >> Body & Frame >> Door Locks >> Immobilizer System >> Diagnostic Information and Procedures >> DTC P1645: ID Code Communication Error >> Troubleshooting
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC P1645: ID Code Communication Error: Troubleshooting

DIAGNOSIS PROCEDURE - ID CODE COMMUNICATION ERROR

Step Action YES NO
Was "Immobilizer Control System Check" performed?  Go to Step 2. Go to IMMOBILIZER CONTROL SYSTEM CHECK .
DTC check of ECM 
1) Check ECM for DTC referring to DTC CHECK .
Is DTC U0073, U0101, U0121 and/or U0140 detected? 
Go to applicable DTC diag. flow. Go to Step 3.
CAN communication circuit check 
  1. Disconnect connectors of all control modules communicating by means of CAN.
  2. Check CAN communication circuit between control modules for open, short and high resistance.

Is each CAN communication circuit in good condition? 
Replace ID controller with new one. If DTC P1645 is still detected, substitute a known-good ECM and recheck. Repair circuit.