2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1871
* DTC P0461, P0462, P0463, P2066, P2067, or P2068 is not set.
* The engine is operating.
* The ignition voltage is greater than 10 V.
* The rear HO2S are at operating temperature for greater than 10 s.
* The fuel injectors are enabled.
* The long term fuel control is enabled.
* The mass air flow sensor is greater than 10 g/s.
* The MAF sensor is between 6-33 g/s for greater than 3 s during the intrusive test.
* The accumulated air flow into the engine is greater than 15 g during the fuel cut-off event.
* DTC P2271 runs continuously when the above conditions are met.
Conditions for Setting the DTC
The ECM detects that the rear HO2S voltage is greater than 650 mV for greater than 100 s, then an intrusive test is performed. The ECM will lean
the fuel mixture up to -7 % and then wait for 10 s at -7 %. If the ECM detects that the HO2S voltage is still greater than 650 mV, the ECM then
tests the HO2S at the next decel fuel cut-off. If the ECM detects the HO2S voltage is greater than 200 mV after 4 s or for a cumulative of 30 s in
decel fuel cut-off, the DTC sets.
Action Taken when the DTC Sets
DTC P2271 is a Type B DTC.
Conditions for Clearing the MIL/DTC
DTC P2271 is a Type B 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)
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
Circuit/System Verification
1. Ignition ON, observe the DTC information with a scan tool. Verify that DTC P0137, P0138, or P0140 is not set.
瀚慖f any of the listed DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code
Descriptions/Diagnostic Trouble Code (DTC) List - Vehicle) for further diagnosis.
2. Operate the engine above 1,200 RPM for 30 s, observe the HO2S 2 voltage parameter. The reading should fluctuate above and below the
range of 350-550 mV.
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the
conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
1. Engine operating, move the related HO2S harness between the B52 HO2S harness connector and the K20 ECM while monitoring the HO2S
2 voltage parameter. Verify that the HO2S 2 parameter does not change abruptly while moving the related harnesses.
