2010 Cadillac CTS Sedan AWD V6-3.6L Page 1030

2010 Cadillac CTS Sedan AWD V6-3.6L Page 1030

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 P0117

- Engine Coolant Temperature (ECT) Sensor Circuit Low Voltage

DTC P0118

- Engine Coolant Temperature (ECT) Sensor Circuit High Voltage

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 volts to the ECT signal circuit and supplies a ground to the low reference circuit.

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

Conditions for Running the DTC

P0117

* The engine is operating.

* The start up intake air temperature (IAT) is less than 72掳C (161掳F).

OR

* The start up intake air temperature (IAT) is greater than 72掳C (161掳F).

* The engine run time is greater than 59 seconds.

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

P0118

* The ignition is ON or the engine is operating.

* The DTC runs continuously once the above condition is met.

Conditions for Setting the DTC