Monday, March 15, 2021

2010 Cadillac CTS Sedan AWD V6-3.6L Page 1098

2010 Cadillac CTS Sedan AWD V6-3.6L Page 1098



* Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 (LF1) (See: Powertrain Management/Computers and Control Systems/Oxygen



Sensor/Service and Repair)Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 (LLT) (See: Powertrain Management/Computers and



Control Systems/Oxygen Sensor/Service and Repair)



* Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 (LF1) (See: Powertrain Management/Computers and Control Systems/Oxygen



Sensor/Service and Repair)Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 (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



programming



P0154



DTC P0134 or P0154 (LLT)



Diagnostic Instructions



* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System



Check - Vehicle) prior to using this diagnostic procedure.



* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an



overview of the diagnostic approach.



* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure



Instructions) provides an overview of each diagnostic category.



DTC Descriptors



DTC P0134



- HO2S Circuit Insufficient Activity Bank 1 Sensor 1



DTC P0154



- HO2S Circuit Insufficient Activity Bank 2 Sensor 1



Diagnostic Fault Information



Typical Scan Tool Data



Circuit Description



The heated oxygen sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding



air with the oxygen content of the exhaust stream. When the engine is started, the control module operates in an Open Loop mode, ignoring the



HO2S signal voltage while calculating the air-to-fuel ratio. The control module supplies the HO2S with a reference, or bias voltage of about 450



mV. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0-1,000 mV. This voltage will fluctuate above



and below the bias voltage. Once sufficient HO2S voltage fluctuation is observed by the control module, Closed Loop is entered. The control



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 DTCs