2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1764

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1764

The engine control module (ECM) uses the engine coolant temperature sensor to monitor the engine for an over-temperature condition. This

condition occurs when the coolant temperature is above a calibrated value. The ECM will alternately disable 2 groups of cylinders by turning OFF

the fuel injectors. By switching between the 2 groups of cylinders, the ECM is able to reduce the temperature of the coolant.

Conditions for Running the DTC

* DTCs P0116, P0117, P0118, P0128 are not set.

* The engine is operating for greater than 30 seconds.

* DTC P1258 runs continuously once the conditions above have been met.

Conditions for Setting the DTC

3.0L - LF1

The ECM detects that engine coolant temperature is warmer than 129掳C (264掳F) for greater than 2 seconds.

3.6L - LLT

The ECM detects that engine coolant temperature is warmer than 136掳C (277掳F) for greater than 1 second.

Action Taken When the DTC Sets

* DTC P1258 is a Type A DTC.

* The engine will operate in the Overheated Engine Protection Operating Mode.

* The IP will illuminate the coolant temperature indicator lamp and the driver information center (DIC), if equipped, may display a message.

Conditions for Clearing the MIL/DTC

DTC P1258 is a Type A DTC.

Reference Information

Schematic Reference

Engine Controls Schematics (LAU) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)Engine Controls Schematics

(LF1) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)

Connector End View Reference

Component Connector End Views (See: Diagrams/Connector Views/Connector End Views By Name)

Description and Operation

* Cooling Fan Description and Operation (LAU) (See: Engine, Cooling and Exhaust/Cooling System/Description and Operation/Cooling Fan

Description and Operation)Cooling Fan Description and Operation (LF1) (See: Engine, Cooling and Exhaust/Cooling System/Description

and Operation/Cooling Fan Description and Operation)

* Instrument Cluster Description and Operation (See: Instrument Panel, Gauges and Warning Indicators/Description and

Operation/Instrument Cluster)

* Indicator/Warning Message Description and Operation (See: Instrument Panel, Gauges and Warning Indicators/Description and

Operation/Indicator/Warning Message)

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)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code

(DTC) Type Definitions)

Scan Tool Reference

Engine Control Module Scan Tool Information (LF1,LFW) (See: Powertrain Management/Computers and Control Systems/Testing and

Inspection/Scan Tool Testing and Procedures)Engine Control Module Scan Tool Information (LAU) (See: Powertrain Management/Computers

and Control Systems/Testing and Inspection/Scan Tool Testing and Procedures) for scan tool information

Circuit/System Verification