2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2441

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2441

Immobilizer Description and Operation (See: Accessories and Optional Equipment/Antitheft and Alarm Systems/Description and

Operation/Immobilizer Description and Operation)

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

Important: Because of normal system communications between the TDM and ECM, any theft deterrent B-codes must be diagnosed prior

to the diagnosis of P-codes.

Perform the 10-Minute Immobilizer Relearn procedure. Refer to Immobilizer System Component Programming (See: Accessories and Optional

Equipment/Antitheft and Alarm Systems/Testing and Inspection/Programming and Relearning). The ECM should successfully complete the

password learn and the vehicle should start.

If the ECM does not complete the learn or vehicle starting remains disabled, replace the ECM.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup and programming

P1668

DTC P1668

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 P1668

- Generator L-Terminal Control Circuit

Diagnostic Fault Information

Circuit/System Description

The engine control module (ECM) uses the generator turn on signal circuit, or L-terminal circuit, to control the load of the generator on the engine.

A high side driver in the ECM applies a voltage to the voltage regulator. This signals the voltage regulator to turn the field circuit ON and OFF.

The ECM monitors the state of the generator turn ON signal circuit. The ECM should detect low voltage on generator turn on signal circuit when

the ignition is ON and the engine is OFF, or when the charging system malfunctions. With the engine running, the ECM should detect high voltage

on the generator turn on signal circuit. The ECM performs tests to determine the status of the generator turn on signal circuit.

Conditions for Running the DTC

The engine is running.

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1768

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.