2010 Cadillac Truck SRX FWD V6-3.0L Page 1881

2010 Cadillac Truck SRX FWD V6-3.0L Page 1881

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 fuel pump control module replacement, setup, and

programming

P1258

DTC P1258

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 Descriptors

DTC P1258

- Engine Coolant Overtemperature - Protection Mode Active

Circuit/System Description

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