2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1768
Immobilizer Description and Operation (See: Accessories and Optional Equipment/Antitheft and Alarm Systems/Description and
Operation/Immobilizer)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit
Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic
Procedures/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General
Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring
Repairs/Wiring Repairs)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning)for scan tool information
Circuit/System Verification
Note: Because of normal system communications between the BCM and ECM, any immobilizer B-codes must be diagnosed prior to the diagnosis
of P-codes.
Perform the BCM immobilizer learn using the Body Control Module IMMO Function with Existing Transponder or Remote Key in SPS. Refer to
Immobilizer System Component Programming (See: Accessories and Optional Equipment/Antitheft and Alarm Systems/Testing and
Inspection/Programming and Relearning). The BCM should successfully complete the learn and the vehicle should start.
If vehicle starting is not restored, perform the ECM immobilizer learn using the Engine Control Module IMMO Learn in SPS. Refer to Immobilizer
System Component Programming (See: Accessories and Optional Equipment/Antitheft and Alarm Systems/Testing and Inspection/Programming
and Relearning).
P1649
DTC P1649
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions)provides an overview of each diagnostic category.
DTC Descriptor
DTC P1649
- Immobilizer Security Code Not Programmed
Circuit/System Description
When learning the security code, as well as the challenge and response sequence, the engine control module (ECM) is placed in learn mode. Once
the security code and challenge/response are learned, learn mode will be exited when the engine is successfully started.
Conditions for Running the DTC
The ECM is in learn mode.
Conditions for Setting the DTC
The ECM has not learned a security code.
Action Taken When the DTC Sets
The security indicator in the instrument cluster will illuminate.
Conditions for Clearing the DTC
* A current DTC P1649 will be cleared upon a successful engine start after exit of learn mode.
