2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1066

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1066

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 mutual performance of the

ECT and the intake air temperature (IAT) signals. The ECM monitors the warm up and cool down behavior of the sensors, after a vehicle driven at

operating temperature is shut down. If the ECM detects that the ECT is not with in a predetermined range of IAT after a long soak, or the ECT and

IAT are not within a range of each other, as compared to a previous cold start, this DTC sets.

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

Conditions for Running the DTC

P0116

* Before the ECM can report DTC P0116 failed, DTC P0101 must run and pass.

* DTC P0100, P0101, P0102, P0103, P0117, P0118, P0119, P0335, P0336, or P0338 is not set.

* The engine speed is greater than 1,000 RPM.

* The engine coolant temperature is less than 93掳C (200掳F).

* The ignition was OFF for greater than 5 Hours after the previous engine shut down.

* The accumulated air mass of the previous ignition cycle was greater than 1,500 g.

* The DTC runs once an ignition cycle when the above conditions are met for greater than 35 s.

P050C

* The time after the engine started is greater than 5 s.

* The accumulated air mass of the previous ignition cycle was greater than 4,000 g.

* The engine run time of the previous ignition cycle was greater than 8 min.

* The ECT at the previous engine shut-down is greater than 85掳C (185掳F).

* The ignition was OFF for greater than 6 h after the previous engine shut-down.

* DTCs P0111, P0112, P0113, P0114, P0117 or P0118 are not set.

* The block heater is not detected.

* This DTC runs continuously.

Conditions for Setting the DTC

* The ECM determines the difference between the ECT and IAT at ignition ON is not within 10掳C (50掳F) of the difference recorded during a

previous ignition cycle, when the enable conditions were met.

OR

* The ECM determines the IAT at ignition ON is within a calibrated range of the ECT and IAT recorded during a previous ignition cycle, but

the ECT is not within 14掳C (25掳F) of the calibrated range.

Action Taken When the DTC Sets

* DTC P0116 is a Type B DTC.

* DTC P050C is a Type A DTC.

Conditions for Clearing the MIL/DTC

* DTC P0116 is a Type B DTC.

* DTC P050C is a Type A DTC.

Diagnostic Aids

* Test the ECT and the IAT 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) and