2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1074

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1074

- Engine Coolant Temperature (ECT) Sensor Circuit Intermittent

Diagnostic Fault Information

Typical Scan Tool Data

Circuit Description

The engine coolant temperature (ECT) sensor is a variable resistor that measures the temperature of the engine coolant. The engine control module

(ECM) supplies 5 V to the ECT signal circuit and supplies a ground to the low reference circuit. The ECM monitors the performance of the ECT

sensor. If the ECM detects excessive noise or rapid fluctuations in the ECT signal, this DTC sets.

The following table illustrates the difference between temperature, resistance, and voltage:

Conditions for Running the DTC

* DTC P0117 or P0118 is not set.

* The ignition is ON or the engine is operating.

* DTC P0119 runs continuously once the above conditions are met.

Conditions for Setting the DTC

* The ECM detects that the ECT changed 卤5掳C (卤9掳F) greater than the expected value during a calibrated amount of time.

* The condition exists for approximately 1 min.

Action Taken When the DTC Sets

DTC P0119 is a Type B DTC.

Conditions for Clearing the MIL/DTC

DTC P0119 is a Type B DTC.

Diagnostic Aids

* Test the ECT sensor at various temperature levels in order to evaluate the possibility of a skewed sensor. A skewed sensor can result in a

DTC or a driveability condition. Refer to Temperature Versus Resistance - Engine Coolant Temperature Sensor (See: Powertrain

Management/Computers and Control Systems/Specifications/Temperature Versus Resistance - Engine Coolant 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 on either the ECT sensor signal circuit or the ECT sensor low reference circuit could set a DTC.

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