Suzuki 2006 SX4, Service Manual

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10C-15 Immobilizer Control System:
DTC P1638: Immobilizer Information Mismatched
S6RW0CA304017
Wiring Diagram
Refer to “Immobilizer Control System Wiring Circuit Diagram”.
Detecting Condition and Trouble Area
Troubleshooting
5 Replacement of BCM
1) Replace BCM with new one referring to “BCM (Included
in Junction Block) Removal and Installation in Section
10B”.
2) Check ECM for DTC referring to “DTC Check”.
Is DTC P1636 still detected?
Substitute a known-
good ECM and recheck. BCM faulty.
Step Action Yes No
Detecting Condition Trouble Area
• The immobilizer control system information in ECM and
the one in BCM does not match.
• The registration of the immobilizer control system
information in ECM is failed.
• Use of the wrong ECM
• CAN communication circuit
• Keyless start control module (if equipped)
• Combination meter
• TCM (A/T model)
• 4WD control module (if equipped)
• ABS control module
• BCM
• ECM
Step Action Yes No
1 Was “Immobilizer Control System Check” performed? Go to Step 2. Go to “Immobilizer
Control System Check”.
2 DTC confirmation
1) Disconnect negative (–) cable from battery for more than
5 seconds.
2) Connect negative (–) cable to battery.
3) Check if any DTC is detected referring to “DTC Check”.
Is DTC P1638 still detected?
Go to Step 3. Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”.
3 ECM specification check
1) Check ECM part number to see if ECM is applicable to
the vehicle in service.
Is a correct ECM used for the vehicle in service?
Go to Step 4. Replace ECM with the
correct one and recheck
if DTC P1638 is still
detected by ECM.
4 DTC check of ECM
1) Check ECM for DTC referring to “DTC Check in Section
1A”.
Is DTC U0073, U0101, U0121 and/or U0140 detected?
Go to applicable DTC
diag. flow. Go to Step 5.
5 DTC check of BCM
1) Check BCM for DTC referring to “DTC Check in Section
10B”.
Is DTC U0073, U0100, U0101, U0155 and/or U1144
detected?
Go to applicable DTC
diag. flow. Go to Step 6.