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
