2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1067
Temperature Versus Resistance - Intake Air Temperature Sensor (See: Powertrain Management/Computers and Control
Systems/Specifications/Temperature Versus Resistance - Intake Air Temperature Sensor).
* If the vehicle has sat overnight, the IAT sensor and the ECT sensor values should display within 3掳C (5掳F).
* After starting a cold engine, the ECT sensor temperature should rise steadily, then stabilize after the thermostat opens.
* High resistance in the circuits of either the ECT or IAT sensor could set a DTC.
* A short to ground or voltage through a conductive material or fluid could set this DTC. Inspect the ECT sensor for evidence of engine
coolant leaking into the connector body.
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
Note: Diagnose DTC P050C first.
1. Verify that DTC P0117, P0118, or P0119 is not set.
瀚慖f any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code
Descriptions/Diagnostic Trouble Code (DTC) List - Vehicle).
2. Inspect the engine coolant level. Verify that the cooling system is operating correctly.
瀚慖f you suspect a condition with engine cooling system, refer to Loss of Coolant (See: Engine, Cooling and Exhaust/Cooling
System/Testing and Inspection/Symptom Related Diagnostic Procedures/Loss of Coolant).
3. Ignition ON, verify the DTC P0116 or P050C Freeze Frame Start-Up ECT and the Start Up IAT parameters are within 10掳C (50掳F).
4. 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 B34 ECT sensor.
2. Ignition OFF, remove the fuse that supplies B+ to circuit terminal 56 X2 of the K20 ECM.
Caution: Do NOT use a test lamp to test the continuity of the circuit. Damage to the control module may occur due to excessive current
draw.
Note: The control module or the sensor may be damaged if the circuit is shorted to battery positive voltage.
3. Test for less than 5 ohm between the low reference circuit terminal 2 and ground.
瀚慖f greater than the specified range, test the low reference circuit for an open/high resistance, or for a short to voltage. If the circuit tests
normal, replace the K20 ECM.
4. Install the fuse that supplies B+ to circuit terminal 56 X2 of the K20 ECM.
5. Ignition ON, verify that the scan tool ECT sensor parameter is at -40掳C (-40掳F).
