2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1817

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1817

P0132, P0138, P0152, or P0158

* The ECM detects that the HO2S voltage is greater than 1,050 mV.

* The DTCs set within 15 s when the above condition is met.

Action Taken When the DTC Sets

DTCs P0131, P0132, P0137, P0138, P0151, P0152, and P0158 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTCs P0131, P0132, P0137, P0138, P0151, P0152, and P0158 are Type B DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics (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/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)

* Heated Oxygen Sensor Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical

Diagnostic Procedures/Wiring Repairs/Heated Oxygen Sensor Wiring 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. Ignition ON, observe the DTC information with a scan tool. Verify no B52 HO2S heater DTCs are set.

瀚慖f a B52 HO2S heater DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code

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

2. Engine running, observe the appropriate scan tool B52 HO2S voltage parameter. The reading should be within the range of 50-1,050 mV.

3. 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

Note: All modules must be powered down or misdiagnosis may result.

1. Ignition OFF, disconnect the harness connector at the appropriate B52 HO2S.

2. Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes, test for less than 5 ohm between the low reference circuit terminal A

and ground.

瀚慖f greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

3. Ignition ON, verify the appropriate scan tool B52 HO2S parameter is approximately 450 mV.

瀚慖f less than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.

瀚慖f greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.

4. Ignition ON, install a 3 A fused jumper wire between the signal circuit terminal B and ground. Verify the appropriate scan tool B52 HO2S

parameter is less than 60 mV.

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1800

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1800

DTC P0131, P0132, P0137, P0138, P0151, P0152, P0157, or P0158

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 P0131

- HO2S Circuit Low Voltage Bank 1 Sensor 1

DTC P0132

- HO2S Circuit High Voltage Bank 1 Sensor 1

DTC P0137

- HO2S Circuit Low Voltage Bank 1 Sensor 2

DTC P0138

- HO2S Circuit High Voltage Bank 1 Sensor 2

DTC P0151

- HO2S Circuit Low Voltage Bank 2 Sensor 1

DTC P0152

- HO2S Circuit High Voltage Bank 2 Sensor 1

DTC P0157

- HO2S Circuit Low Voltage Bank 2 Sensor 2

DTC P0158

- HO2S Circuit High Voltage Bank 2 Sensor 2

Diagnostic Fault Information

Typical Scan Tool Data

Circuit/System 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. While the engine runs, the HO2S heats up and begins to generate a voltage within a

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1789

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1789

DTCs P0131, P0132, P0137, P0138, P0151, P0152, and P0158 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTCs P0131, P0132, P0137, P0138, P0151, P0152, and P0158 are Type B DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics (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/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)

* Heated Oxygen Sensor Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical

Diagnostic Procedures/Wiring Repairs/Heated Oxygen Sensor Wiring 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. Ignition ON, observe the DTC information with a scan tool. Verify no B52 HO2S heater DTCs are set.

瀚慖f a B52 HO2S heater DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code

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

2. Engine running, observe the appropriate scan tool B52 HO2S voltage parameter. The reading should be within the range of 50-1,050 mV.

3. 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

Note: All modules must be powered down or misdiagnosis may result.

1. Ignition OFF, disconnect the harness connector at the appropriate B52 HO2S.

2. Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes, test for less than 5 ohm between the low reference circuit terminal A

and ground.

瀚慖f greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

3. Ignition ON, verify the appropriate scan tool B52 HO2S parameter is approximately 450 mV.

瀚慖f less than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.

瀚慖f greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.

4. Ignition ON, install a 3 A fused jumper wire between the signal circuit terminal B and ground. Verify the appropriate scan tool B52 HO2S

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 tests normal, replace the K20 ECM.

5. If all circuits test normal, replace the appropriate B52 HO2S.

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1786

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1786

DTCs P0131, P0132, P0137, P0138, P0151, P0152, and P0158 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTCs P0131, P0132, P0137, P0138, P0151, P0152, and P0158 are Type B DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics (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/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)

* Heated Oxygen Sensor Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical

Diagnostic Procedures/Wiring Repairs/Heated Oxygen Sensor Wiring 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. Ignition ON, observe the DTC information with a scan tool. Verify no B52 HO2S heater DTCs are set.

瀚慖f a B52 HO2S heater DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code

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

2. Engine running, observe the appropriate scan tool B52 HO2S voltage parameter. The reading should be within the range of 50-1,050 mV.

3. 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

Note: All modules must be powered down or misdiagnosis may result.

1. Ignition OFF, disconnect the harness connector at the appropriate B52 HO2S.

2. Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes, test for less than 5 ohm between the low reference circuit terminal A

and ground.

瀚慖f greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

3. Ignition ON, verify the appropriate scan tool B52 HO2S parameter is approximately 450 mV.

瀚慖f less than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.

瀚慖f greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.

4. Ignition ON, install a 3 A fused jumper wire between the signal circuit terminal B and ground. Verify the appropriate scan tool B52 HO2S

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 tests normal, replace the K20 ECM.

5. If all circuits test normal, replace the appropriate B52 HO2S.

2010 Cadillac Truck Escalade ESV AWD V8-6.2L Page 1918

2010 Cadillac Truck Escalade ESV AWD V8-6.2L Page 1918

P0132, P0138, P0152, or P0158

* The ECM detects that the HO2S voltage is greater than 1,050 mV.

* The DTCs set within 15 s when the above condition is met.

Action Taken When the DTC Sets

DTCs P0131, P0132, P0137, P0138, P0151, P0152, and P0158 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTCs P0131, P0132, P0137, P0138, P0151, P0152, and P0158 are Type B DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics (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/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)

* Heated Oxygen Sensor Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical

Diagnostic Procedures/Wiring Repairs/Heated Oxygen Sensor Wiring 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. Ignition ON, observe the DTC information with a scan tool. Verify no B52 HO2S heater DTCs are set.

锟斤拷If a B52 HO2S heater DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code

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

2. Engine running, observe the appropriate scan tool B52 HO2S voltage parameter. The reading should be within the range of 50-1,050 mV.

3. 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

Note: All modules must be powered down or misdiagnosis may result.

1. Ignition OFF, disconnect the harness connector at the appropriate B52 HO2S.

2. Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes, test for less than 5 ohm between the low reference circuit terminal A

and ground.

锟斤拷If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

3. Ignition ON, verify the appropriate scan tool B52 HO2S parameter is approximately 450 mV.

锟斤拷If less than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.

锟斤拷If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.

4. Ignition ON, install a 3 A fused jumper wire between the signal circuit terminal B and ground. Verify the appropriate scan tool B52 HO2S

parameter is less than 60 mV.

2010 Cadillac Truck Escalade ESV AWD V8-6.2L Page 1901

2010 Cadillac Truck Escalade ESV AWD V8-6.2L Page 1901

DTC P0131, P0132, P0137, P0138, P0151, P0152, P0157, or P0158

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 P0131

- HO2S Circuit Low Voltage Bank 1 Sensor 1

DTC P0132

- HO2S Circuit High Voltage Bank 1 Sensor 1

DTC P0137

- HO2S Circuit Low Voltage Bank 1 Sensor 2

DTC P0138

- HO2S Circuit High Voltage Bank 1 Sensor 2

DTC P0151

- HO2S Circuit Low Voltage Bank 2 Sensor 1

DTC P0152

- HO2S Circuit High Voltage Bank 2 Sensor 1

DTC P0157

- HO2S Circuit Low Voltage Bank 2 Sensor 2

DTC P0158

- HO2S Circuit High Voltage Bank 2 Sensor 2

Diagnostic Fault Information

Typical Scan Tool Data

Circuit/System 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. While the engine runs, the HO2S heats up and begins to generate a voltage within a

2010 Cadillac Truck Escalade ESV AWD V8-6.2L Page 1890

2010 Cadillac Truck Escalade ESV AWD V8-6.2L Page 1890

DTCs P0131, P0132, P0137, P0138, P0151, P0152, and P0158 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTCs P0131, P0132, P0137, P0138, P0151, P0152, and P0158 are Type B DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics (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/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)

* Heated Oxygen Sensor Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical

Diagnostic Procedures/Wiring Repairs/Heated Oxygen Sensor Wiring 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. Ignition ON, observe the DTC information with a scan tool. Verify no B52 HO2S heater DTCs are set.

锟斤拷If a B52 HO2S heater DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code

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

2. Engine running, observe the appropriate scan tool B52 HO2S voltage parameter. The reading should be within the range of 50-1,050 mV.

3. 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

Note: All modules must be powered down or misdiagnosis may result.

1. Ignition OFF, disconnect the harness connector at the appropriate B52 HO2S.

2. Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes, test for less than 5 ohm between the low reference circuit terminal A

and ground.

锟斤拷If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

3. Ignition ON, verify the appropriate scan tool B52 HO2S parameter is approximately 450 mV.

锟斤拷If less than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.

锟斤拷If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.

4. Ignition ON, install a 3 A fused jumper wire between the signal circuit terminal B and ground. Verify the appropriate scan tool B52 HO2S

parameter is less than 60 mV.

锟斤拷If greater than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.

5. If all circuits test normal, replace the appropriate B52 HO2S.

2010 Cadillac Truck Escalade ESV AWD V8-6.2L Page 1887

2010 Cadillac Truck Escalade ESV AWD V8-6.2L Page 1887

DTCs P0131, P0132, P0137, P0138, P0151, P0152, and P0158 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTCs P0131, P0132, P0137, P0138, P0151, P0152, and P0158 are Type B DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics (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/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)

* Heated Oxygen Sensor Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical

Diagnostic Procedures/Wiring Repairs/Heated Oxygen Sensor Wiring 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. Ignition ON, observe the DTC information with a scan tool. Verify no B52 HO2S heater DTCs are set.

锟斤拷If a B52 HO2S heater DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code

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

2. Engine running, observe the appropriate scan tool B52 HO2S voltage parameter. The reading should be within the range of 50-1,050 mV.

3. 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

Note: All modules must be powered down or misdiagnosis may result.

1. Ignition OFF, disconnect the harness connector at the appropriate B52 HO2S.

2. Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes, test for less than 5 ohm between the low reference circuit terminal A

and ground.

锟斤拷If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

3. Ignition ON, verify the appropriate scan tool B52 HO2S parameter is approximately 450 mV.

锟斤拷If less than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.

锟斤拷If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.

4. Ignition ON, install a 3 A fused jumper wire between the signal circuit terminal B and ground. Verify the appropriate scan tool B52 HO2S

parameter is less than 60 mV.

锟斤拷If greater than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.

5. If all circuits test normal, replace the appropriate B52 HO2S.