Check Engine Light Came On (Oh lucky me!)

[Aveo5_boy]

According to the Chilton Manual.....

2009 Aveo:

1.6L (LXT Engine)

The Engine Coolant Temperature (ECT) Sensor is located on the cylinder head below the intake manifold.




1.6L (LXT Engine)

1. Before servicing the vehicle, refer to the precautions section.
2. Disconnect the negative battery cable.
3. Relieve the coolant system pressure.
4. Disconnect the negative battery cable.
5. Drain the coolant below the Engine Coolant Temperature (ECT) sensor level.
6. Disconnect the ECT sensor connector.
7. Remove the ECT sensor.
   

To install:

1. Tighten the ECT sensor to 15 ft. lbs. (20 Nm).
2. Connect the ECT sensor connector.
3. Refill and bleed the cooling system.
4. Connect the negative battery cable.

LXV Engine
ECT 1

The Engine Coolant Temperature (ECT) Sensor— ECT 1 is located at the rear of the cylinder head in the coolant jacket. It sits just below the intake camshaft sensor.




ECT 2

The Engine Coolant Temperature (ECT) Sensor— ECT 2 is located at the bottom of the radiator.




ECT 1

1. Before servicing the vehicle, refer to the precautions section.
2. Disconnect the negative battery cable.
3. Drain the engine coolant.
4. Disconnect the ECT sensor connector.
5. Remove the ECT retaining clip.
6. Remove the ECT from the coolant distributor.

To install:

1. Install the ECT to the coolant distributor.
2. Install the ECT retaining clip.
3. Connect the ECT sensor connector.
4. Refill and bleed the cooling system.
5. Connect the negative battery cable.

ECT 2

1. Before servicing the vehicle, refer to the precautions section.
2. Disconnect the negative battery cable.
3. Drain the engine coolant.
4. Drain the engine coolant.
5. Disconnect the ECT 2 sensor connector.
6. Remove the ECT 2 sensor from the radiator.

To install:

1. Install the ECT 2 sensor to the radiator. Tighten the ECT 2 sensor to 15 ft. lbs. (20 Nm).
2. Connect the ECT 2 sensor connector.
3. Refill and bleed the cooling system.
4. Connect the negative battery cable.

Testing:

Connection & Wiring Diagnosis

Refer to the Electrical Wiring Diagram for component and connector locations, connector views, and circuit-specific information.
Many intermittent open or short circuits may be caused by wiring harness and connector movement due to vibration, engine torque, bumps and rough pavement, etc.

1. Test the wiring harness and connectors by performing the following tests:
   
   • Move the related connectors and wiring while monitoring the appropriate scan tool data.
   • Move the related connectors and wiring with the component commanded ON and OFF. Using a suitable the scan tool, observe the component operation.
   • With the engine running, move the related connectors and wiring while monitoring component operation.
   • If harness or connector movement affects the data displayed, the component and system operation, or the engine operation, inspect and repair the harness or connections as necessary.
   
   
2. Test the connector terminal pins and/or wiring by performing the following tests:
   
   • Inspect for incorrect mating of the connector halves, or terminals not fully seated in the connector body.
   • Inspect for improperly formed or damaged terminals and test for incorrect terminal tension.
   • Inspect for poor terminal to wire connections including terminals crimped over insulation. This requires removing the terminal from the connector body.
   • Inspect for corrosion or water intrusion. Pierced or damaged insulation can allow moisture to enter the wiring. The conductor can corrode inside the insulation with little visible evidence. Look for swollen and/or brittle sections of wire in the suspect circuits.
   • Inspect for wires that are broken inside the insulation by gently pulling on suspect sections of wiring.

ECT Circuit Testing

Use a suitable scan tool, a Graphing Multi–Meter (GMM), or a Digital Volt–Ohm Meter (DVOM) in order to view the ECT data.
ECT Sensor logic is relative to the scale of resistance: when the coolant temperature is low, the voltage is increased. When the coolant temperature is high, the voltage is decreased.
Use a suitable pyrometer or thermometer, as well as visual observation to verify that the cooling system is operating properly. If a cooling system fault is evident, repair as required before continuing.
If a DVOM is being used, additional information may be acquired by taking measurements at the sensor connector as well as the PCM connector. If a significant voltage drop is measured (greater than 0.5 volts DC), check the wiring harness and connections for corrosion, poor pin connections, or damaged wires.
If all engine wiring and pin connections are confirmed, disconnect the ECT Sensor to verify the signal with a DVOM, and verify PCM communication before replacing the ECT Sensor.


ECT Sensor Strategy

The ECT Sensor provides a linear input signal to the Powertrain Control Module (PCM) for a number of engine control system calculations. The ECT signal is compared with Manifold Absolute Pressure (MAP), Mass Air Flow (MAF), Intake Air Temperature (IAT), and Fuel Trim (HO2S) in order to determine the correct air-fuel mixture for measured operating conditions. In some cases the ECT Sensor input is used in concert with the A/C Pressure (ACP) Sensor input in order to determine cooling fan and A/C system operation.


Related Diagnostic Trouble Codes

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