2010 Cadillac CTS Sedan AWD V6-3.6L Page 944
Circuit/System Description
Heated oxygen sensors (HO2S) are used for fuel control and post catalyst monitoring. Each HO2S compares the oxygen content of the surrounding
air with the oxygen content in the exhaust stream. The HO2S must reach operating temperature to provide an accurate voltage signal. A heating
element inside the HO2S minimizes the time required for the sensors to reach operating temperature. Voltage is provided to the heater by an
ignition voltage circuit through a fuse. With the engine running, ground is provided to the heater by the HO2S heater low control circuit through a
low side driver within the engine control module (ECM). The ECM uses pulse width modulation (PWM) to control the HO2S heater operation to
maintain a specific HO2S operating temperature range.
Conditions for Running the DTC
P0030, P0036, P0050, or P0056
* The ignition 1 voltage is between 11-18 V.
* The engine speed is greater than 400 RPM.
* The DTCs run continuously when the above conditions are met.
P0053, P0054, P0059, or P0060
* DTCs P0112, P0113, P0117, P0118, or P2610 are not set.
* The engine run time is greater than 20 s.
* The ignition voltage is less than 18 V.
* The ignition is OFF for greater than 8 h.
* The engine coolant temperature (ECT) is between -30 to +45掳C (-22 to +113掳F) at engine start-up.
* The ECT and the intake air temperature (IAT) are within 8掳C (14掳F) at engine start-up.
* The DTCs run once per drive cycle when the above conditions are met.
P0135, P0141, P0155, or P0161
* DTCs P0116, P0117, P0118, P0125, or P0128 are not set.
* The ignition 1 voltage is between 10-32 V.
* The HO2S is at operating temperature.
* The HO2S is commanded ON.
* The DTCs run once per drive cycle when the above conditions are met for 120 s.
Conditions for Setting the DTC
P0030, P0036, P0050, or P0056
The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for greater than 5 s.
P0053, P0054, P0059, or P0060
The ECM detects the HO2S heater is not within a specified resistance range at engine start-up.
P0135 or P0155
The ECM detects that the HO2S 1 heater current is greater than 3.1 amps, or less than 0.3 amps for greater than 8 s.
P0141 or P0161
The ECM detects that the HO2S 2 heater current is greater than 2.9 amps, or less than 0.3 amps for greater than 8 s.
Action Taken When the DTC Sets
DTCs P0030, P0036, P0050, P0053, P0054, P0056, P0059, P0060, P0135, P0141. P0155, and P0161 are Type B DTCs.
Conditions for Clearing the MIL/DTC
DTCs P0030, P0036, P0050, P0053, P0054, P0056, P0059, P0060, P0135, P0141. P0155, and P0161 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)
