2010 Cadillac CTS Sedan AWD V6-3.6L Page 1081

2010 Cadillac CTS Sedan AWD V6-3.6L Page 1081

* DTC P0036, P0037, P0038, P0056, P0057, P0058, P0116, P0117, P0118, P0119, or P0128 is not set.

* The engine speed is greater than 240 RPM.

* The ignition voltage is greater than 10 volts.

* The engine coolant temperature is colder than 40掳C (104掳F) at start-up and the engine coolant temperature was warmer than 60掳C (140掳F)

when the ignition was turned OFF last ignition cycle.

* The calculated exhaust temperature at the HO2S 2 is warmer than 700掳C (1,292掳F) and the HO2S 2 is warmed up for greater than 90

seconds.

* The calculated exhaust temperature is colder than 800掳C (1472掳F) 5 seconds after engine start.

* DTCs P0137 and P0157 run continuously once the above conditions are met.

P0138, P0140, P0158, and P0160

* The engine speed is greater than 240 RPM.

* The ignition voltage is greater than 10 volts.

* The HO2S 2 heater duty cycle is stable and the HO2S 2 is warmed up for greater than 90 seconds.

* The calculated exhaust temperature is colder than 800掳C (1472掳F).

* DTCs P0138 and P0158 run continuously once the above conditions are met for greater than 5 seconds.

* DTCs P0140 and P0160 run continuously once the above conditions are met for greater than 60 seconds.

Conditions for Setting the DTC

P0137 or P0157

The ECM detects that a secondary HO2S signal voltage is less than 60 mV for greater than 1 seconds of for a cumulative of 10 seconds.

P0138 or P0158

The ECM detects that the HO2S signal voltage is greater than 1,150 mV for greater than 1 seconds or for a cumulative of 10 seconds.

P0140 or P0160

* The ECM detects that the HO2S 2 signal voltage is between 401-519 mV.

* The ECM detects that the measured internal resistance of the HO2S 2 is greater than 40,000 ohms, when the calculated exhaust temperature

is warmer than 500掳C (932掳F).

* Either condition exists for greater than 1 second or for a cumulative of 10 seconds.

Action Taken when the DTC Sets

DTCs P0137, P0138, P0140, P0157, P0158, and P0160 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTCs P0137, P0138, P0140, P0157, P0158, and P0160 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 2 voltage parameter. The reading should fluctuate above and below the range of

2010 Cadillac CTS Sedan AWD V6-3.6L Page 914

2010 Cadillac CTS Sedan AWD V6-3.6L Page 914

DTC P0030, P0031, P0032, P0036, P0037, P0038, P0050, P0051, P0052, P0056, P0057, or P0058 (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 P0030

- HO2S Heater Control Circuit Bank 1 Sensor 1

DTC P0031

- HO2S Heater Control Circuit Low Voltage Bank 1 Sensor 1

DTC P0032

- HO2S Heater Control Circuit High Voltage Bank 1 Sensor 1

DTC P0036

- Heater Control Circuit Bank 1 Sensor 2

DTC P0037

- HO2S Heater Control Circuit Low Voltage Bank 1 Sensor 2

DTC P0038

- HO2S Heater Control Circuit High Voltage Bank 1 Sensor 2

DTC P0050

- HO2S Heater Control Circuit Bank 2 Sensor 1

DTC P0051

- HO2S Heater Control Circuit Low Voltage Bank 2 Sensor 1

DTC P0052

- HO2S Heater Control Circuit High Voltage Bank 2 Sensor 1

DTC P0056

- HO2S Heater Control Circuit Bank 2 Sensor 2

DTC P0057

- HO2S Heater Control Circuit Low Voltage Bank 2 Sensor 2

DTC P0058

- HO2S Heater Control Circuit High Voltage Bank 2 Sensor 2

Diagnostic Fault Information

Circuit Description

The heated oxygen sensor (HO2S) heater reduces the time required for the oxygen sensor to reach operating temperature and maintains the

operating temperature during extended idle periods. When the ignition is turned to the ON position, ignition voltage is supplied directly to the

sensor heater. The engine control module (ECM) controls the heater operation by first modulating the control circuit to ground when the sensors are

cold. This prevents the possibility of thermal shock to the sensor, from condensation build-up on the sensor, by controlling the sensors rate of

heating. After a predetermined amount of time, the ECM commands the heaters ON continuously. Once the sensor reaches operating temperature,

the ECM may modulate the heater control circuit to ground, to maintain a desired temperature.

2010 Cadillac CTS Sedan AWD V6-3.6L Page 925

2010 Cadillac CTS Sedan AWD V6-3.6L Page 925

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

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 at operating temperature for at least 30 seconds. Observe the DTC information, DTCs P0030, P0031, P0032, P0036, P0037,

P0038, P0050, P0051, P0052, P0056, P0057, and P0058 should not set.

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 heated oxygen sensor (HO2S).

2. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal D and ground.

Note: The ignition circuit supplies voltage to other components. Make sure you test all circuits for a short to ground or test all components

for being shorted that share the ignition circuit.

瀚慖f the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and

the ignition circuit fuse is open, test all the components connected to the ignition circuit and replace as necessary.

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 948

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 948

* DTC P0036, P0037, P0038, P0130, P0137, P0138, P0140, P0141, P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0443, P0458,

P0459, P2096, P2097, P2177, P2178, P2179, P2787, P2088, P2089, P2090, P2232, P2235, P2270, P2271, P2272, or P2273 is not set.

* The engine speed is 1,200-3,000 RPM.

* The HO2S 1 is in Closed Loop.

* The engine load is 18-75 %.

* The exhaust gas temperature is greater than 300掳C (572掳F).

* The evaporative purge (EVAP) solenoid valve is commanded OFF or ON for greater than 10 s.

* These DTCs run continuously when the conditions above exist.

Conditions for Setting the DTCs

The ECM determines that the length of time for an HO2S 1 to switch from lean to rich and back to lean, which is called a switching cycle, has

exceeded a predetermined threshold. The condition exists for 3 cycles out of a 20 cycle test sample.

Action Taken when the DTCs Set

DTCs P0133, P013A, and P013E are Type B DTCs.

Conditions for Clearing the MIL/DTCs

DTCs P0133, P013A, and P013E are Type B DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics (LAU) (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/Connector End Views By Name)

Electrical Information Reference

* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit

Testing/Circuit Testing)

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/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. Verify that other DTCs are not set.

瀚慖f any other DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code

Descriptions/Diagnostic Trouble Code (DTC) List - Vehicle).

2. Engine idling at operating temperature, observe the appropriate B52 HO2S parameter with a scan tool. Verify the following:

* The B52 HO2S 1 value should vary from below 200 mV to above 800 mV and respond to fueling changes.

* The B52 HO2S 2 value should change greater than 200 mV when the throttle is quickly cycled 3 times from closed to wide open and

back to closed after running the engine at 1,500 RPM for 30 s.

3. Engine idling, observe the scan tool HO2S 1 voltage parameter. The voltage should fluctuate above and below the range of 350-550 mV.

4. Observe the DTC information with a scan tool. DTCs P0133, P013A, and P013E should not set.

5. 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. Verify that none of the following conditions exist: