2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1829

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1829

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

range of 0-1,275 mV. 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 toward 1,000 mV indicates a rich fuel mixture. An HO2S

voltage that decreases 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 DTC

P0131, P0137, P0151, or P0157

* DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128,

P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1516,

P2101, P2119, P2135, P2176 are not set.

* The engine is operating in Closed Loop.

* The Ignition 1 voltage is between 10-32 V.

* The fuel level is greater than 10 %.

* The throttle position (TP) is between 3-70 %.

* The DTCs run continuously when the above conditions are met for 2 s.

P0132, P0138, P0152, or P0158

* DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128,

P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1516,

P2101, P2119, P2135, P2176 are not set.

* The engine is operating in Closed Loop.

* The Ignition 1 voltage is between 10-32 V.

* The fuel level is greater than 10 %.

* The throttle position (TP) is between 0-70 %.

* The DTCs run continuously when the above conditions are met for 2 s.

Conditions for Setting the DTC

P0131, P0137, P0151, or P0157

* The ECM detects that the HO2S voltage is less than 50 mV.

* The DTCs set within 100 s when the above condition is met.

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)