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