2010 Cadillac Truck SRX AWD V6-3.0L Page 1139
DTC P0117 or P0118 (LF1)
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 V 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 s.
* 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
