2010 Cadillac CTS Sedan AWD V6-3.6L Page 1950
* The ECM monitors the HO2S voltage to determine if the signal voltage goes above a predetermined threshold within a certain amount of
time. If the ECM determines that the signal voltage remains below a threshold, the ECM will command the fuel system rich to determine if
the HO2S signal voltage can be forced above the threshold within a certain amount of time.
* The ECM monitors the HO2S voltage during power enrichment to ensure that the signal voltage goes above a predetermined threshold during
power enrichment.
Conditions for Running the DTC
* Before the ECM can report DTC P2270 or P2272 failed, DTCs P0036, P0037, P0038, P0056, P0057, P0058, P013A, P013C, P013E, P0137,
P0138, P014A, P0140, P0141, P0157, P0158, P0160, P0161, P0443, P0458, P0459, P2096, P2098, P2177, P2179, P2187, and P2189 must
run and pass.
* DTC P0461, P0462, P0463, P2066, P2067, or P2068 is not set.
* The engine speed is greater than 240 RPM.
* The ignition voltage is greater than 10 volts.
* The HO2S 2 is at operating temperature for greater than 10 seconds.
* The long term fuel control is enabled.
* The mass air flow (MAF) signal is greater than 10 g/s.
* The MAF signal is between 6-33 g/s for greater than 3 seconds during the intrusive test.
* DTCs P2270 and P2272 run continuously when the above conditions are met for approximately 10 minutes, or 20 minutes if the fuel level is
less than 12 percent.
Conditions for Setting the DTC
The ECM detects that the HO2S 2 voltage is less than 629 mV for greater than 100 seconds, then an intrusive test is performed. The ECM will
enrich the fuel mixture 2 percent per second and then wait for 10 seconds at 20 percent. If the ECM detects that the HO2S 2 voltage is still less than
629 mV during the intrusive test, for greater than 4 second or for a cumulative of 30 seconds the DTC sets.
Action Taken when the DTC Sets
DTCs P2270 and P2272 are Type B DTCs.
Conditions for Clearing the MIL/DTC
DTCs P2270 and P2272 are Type B DTCs.
Reference Information
Schematic Reference
Engine Controls Schematics (LLT) (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)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit
Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/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, P0140, P0157, P0158, or P0160 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 seconds, observe the HO2S voltage parameter. The reading should fluctuate above and below
the range of 401-519 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
