2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1253

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1253

P0300

The ECM detects a crankshaft rotation speed variation indicating a misfire rate sufficient to cause emissions levels to exceed a predetermined value.

P0301, P0302, P0303, P0304, P0305, P0306

The ECM detects a crankshaft rotation speed variation indicating a single cylinder misfire rate sufficient to cause emissions levels to exceed

mandated standards.

Action Taken When the DTC Sets

* DTCs P0300-P0306 are Type B DTCs.

* When the MIL is flashing, the injector may be disabled for the misfiring cylinder to protect the catalytic converter.

* Depending on the conditions that set the code, the engine may go into Open Loop.

Conditions for Clearing the DTC

* DTCs P0300-P0306 are Type B DTCs.

* The DTC must pass under the same conditions that were present when the DTC failed.

Diagnostic Aids

* A misfire DTC could be caused by an excessive vibration from sources other than the engine. Inspect for the following possible sources:

- A tire or wheel that is out of round or out of balance

- Variable thickness brake rotors

- An unbalanced drive shaft

- Certain rough road conditions

- Transmission operation

- A damaged accessory drive component or belt; remove the belt and safely operate the engine to evaluate

* High resistance in the circuits of the injectors could set a misfire DTC without setting an injector DTC. Test the injector circuits of the

affected cylinder(s) for a high resistance if you suspect a condition.

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)

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)

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

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Special Tools

J 26792 HEI Spark Tester

Circuit/System Verification

1. Engine idling at the normal operating temperature, there should be no abnormal engine noise.

瀚慖f there is an abnormal engine noise, refer to Symptoms - Engine Mechanical (See: Engine, Cooling and Exhaust/Engine/Testing and