2010 Cadillac CTS Sedan AWD V6-3.6L Page 859
Circuit/System Verification
1. Ignition ON, observe the scan tool DTC information. Verify no other DTC is set.
瀚慖f any other DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic
Trouble Code (DTC) List - Vehicle).
2. Engine idling, observe the appropriate scan tool HO2S voltage parameter. The voltage should fluctuate above and below the range of
401-519 mV.
3. Observe the DTC information with a scan tool. DTC P013A, P013C, P013E, and P014A should not set.
4. 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 400-520 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. Connect 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 mV.
瀚慖f greater than the specified range, test the signal circuit for an open/high resistance. If the circuit/connections test normal, replace the
ECM.
4. Connect a 3 A fused jumper wire between the signal circuit terminal B and the low reference circuit terminal A. Verify the scan tool HO2S
voltage parameter is less than 60 mV.
瀚慖f greater than the specified range, test the low reference circuit for an open/high resistance or for a short to voltage. If the
circuit/connections test normal, replace the ECM.
5. Verify that none of the following conditions exist:
* Lean or rich condition.
* Water intrusion in the HO2S harness connector
* HO2S wiring harness damage
* Incorrect RTV sealant
* Low or high fuel system pressure-Refer to Fuel System Diagnosis (See: Powertrain Management/Computers and Control
Systems/Testing and Inspection/Component Tests and General Diagnostics/Fuel System Diagnosis).
* Fuel that is contaminated-Refer to Alcohol/Contaminants-in-Fuel Diagnosis (with Special Tool) (See: Powertrain
Management/Computers and Control Systems/Testing and Inspection/Component Tests and General
Diagnostics/Alcohol/Contaminants-in-Fuel Diagnosis (with Special Tool))Alcohol/Contaminants-in-Fuel Diagnosis (without Special
Tool) (See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Component Tests and General
Diagnostics/Alcohol/Contaminants-in-Fuel Diagnosis (without Special Tool)).
* Fuel saturation of the evaporative emission (EVAP) canister
* Exhaust leaks near the HO2S
* Engine vacuum leaks
* Engine oil consumption
* Engine coolant consumption
瀚慖f you find any of the above conditions, repair as necessary.
6. If all conditions test normal, replace the appropriate HO2S.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 (LF1) (See: Powertrain Management/Computers and Control Systems/Oxygen
Sensor/Service and Repair)Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 (LLT) (See: Powertrain Management/Computers and
Control Systems/Oxygen Sensor/Service and Repair)
* Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 (LF1) (See: Powertrain Management/Computers and Control Systems/Oxygen
Sensor/Service and Repair)Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 (LLT) (See: Powertrain Management/Computers and
Control Systems/Oxygen Sensor/Service and Repair)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for engine control module replacement, setup, and
