2010 Cadillac CTS Sedan AWD V6-3.6L Page 1064
module uses the HO2S voltage to determine the air-to-fuel ratio. An HO2S voltage that increases above bias voltage toward 1,000 mV indicates a
rich fuel mixture. An HO2S voltage that decreases below bias voltage toward 0 mV indicates a lean fuel mixture.
The heating elements inside each HO2S heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed
Loop earlier and the control module to calculate the air-to-fuel ratio sooner.
Conditions for Running the DTC
* DTC P0201, P0202, P0203, P0204, P0205, P0206 P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276,
P0277, P2146, P2149, P2152, P2155, P216A, or P216D is not set.
* The ignition voltage is greater than 10 volts.
* The engine speed is greater than 240 RPM.
* The HO2S 1 heater duty cycle is greater than 90 percent for greater than 5 seconds.
* The ECM is not commanding the air/fuel mixture rich.
* DTC P0132 and P0152 run continuously once the conditions above exist for greater than 5 seconds.
Conditions for Setting the DTC
The ECM detects that an HO2S 1 signal voltage is greater than 1,150 mV.
Action Taken when the DTC Sets
DTCs P0132 and P0152 are Type B DTCs.
Conditions for Clearing the MIL/DTC
DTCs P0132 and P0152 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. Engine idling, observe the appropriate scan tool HO2S 1 voltage parameter. The voltage should fluctuate above and below the range of
350-550 mV.
2. 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. Ignition OFF, disconnect the harness connector at the appropriate HO2S.
2. Ignition ON, verify that the scan tool HO2S voltage parameter is between 350-500 mV.
瀚慖f less than the specified range, test the signal circuit terminal B for a short to ground. If the circuit/connections test normal, replace the
ECM.
瀚慖f greater than the specified range, test the signal circuit terminal B for a short to voltage. If the circuit/connections test normal, replace
the ECM.
3. Install a 3 A fused jumper wire between the signal circuit terminal B and ground. Verify the scan tool HO2S voltage parameter is less than 60
