2010 Cadillac CTS Sedan AWD V6-3.6L Page 915
The ECM controls the heater by grounding the control circuit with a solid state device called a driver. The driver is equipped with a feedback
circuit that is pulled-up to voltage. The ECM can determine if the control circuit is open, shorted to ground, or shorted to a voltage by monitoring
the feedback voltage.
The HO2S utilizes the following circuits:
* A signal circuit
* A low reference circuit
* An ignition voltage circuit
* A heater control circuit
Conditions for Running the DTC
P0030, P0031, P0032, P0050, P0051, P0052
* The ignition voltage is between 10-18 volts.
* The engine speed is greater than 80 RPM, 240 RPM for LLT.
* The HO2S heater is commanded ON and OFF at least once during the ignition cycle.
* The HO2S heater is commanded ON-LLT only.
* The DTCs run continuously when the above conditions are met-5 seconds for LLT.
P0036, P0037, P0038, P0056, P0057, P0058
* The ignition voltage is between 10-18 volts.
* The engine speed is greater than 80 RPM.
* The HO2S heater is commanded ON and OFF at least once during the ignition cycle.
* The HO2S 2 is at operating temperature.
* The DTCs run continuously when the above conditions are met for greater than 500 mS.
Conditions for Setting the DTC
P0030, P0036, P0050, and P0056
The ECM detects an open in the heater circuits of the HO2S when the heater is commanded OFF. The condition exists for greater than 4 seconds or
a cumulative of 30 seconds.
P0031, P0037, P0051, and P0057
The ECM detects a short to ground in the heater circuits of the HO2S when the heater is commanded OFF. The condition exists for greater than 4
seconds or a cumulative of 30 seconds.
P0032, P0038, P0052, and P0058
The ECM detects a short to voltage in the heater circuits of the HO2S when the heater is commanded ON. The condition exists for greater than 4
seconds or a cumulative of 30 seconds.
Action Taken When the DTC Sets
DTCs P0030, P0031, P0032, P0036, P0037, P0038, P0050, P0051, P0052, P0056, P0057, and P0058 are Type B DTCs.
Conditions for Clearing the MIL/DTC
DTCs P0030, P0031, P0032, P0036, P0037, P0038, P0050, P0051, P0052, P0056, P0057, and P0058 are Type B DTCs.
Diagnostic Aids
* If the condition is intermittent, move the related harnesses and connectors, with the engine operating, while monitoring the scan tool Circuit
Test Status parameters for the component. The circuit status parameters change from OK or Not Run to Fault if there is a condition with the
circuit or a connection.
* An open fuse in the HO2S heater circuit may be caused by the heater element in one of the sensors. The condition may not be present until
the sensor operates for a period of time. If no fault is present in the heater circuit, monitor the amperage of each heater using the DMM to
determine if one of the heater elements is the cause of the open fuse. Inspect the sensor pigtail or the harness for contacting the exhaust
system.
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
