Cruze L4-1.4L Turbo (2011)
The engine control module (ECM), by design, can withstand the normal current draws that are associated with the vehicle operations. However, care
must be taken in order to avoid overloading any of these circuits. When testing for opens or shorts, do not ground or apply voltage to any of the ECM
circuits unless the diagnostic procedure instructs you to do so. These circuits should only be tested with a DMM.
Aftermarket (Add-On) Electrical And Vacuum Equipment
Caution: Do not attach add-on vacuum operated equipment to this vehicle. The use of add-on vacuum equipment may result in damage to vehicle
components or systems.
Caution: Connect any add-on electrically operated equipment to the vehicle's electrical system at the battery (power and ground) in order to prevent
damage to the vehicle.
Aftermarket, add-on, electrical and vacuum equipment is defined as any equipment installed on a vehicle after leaving the factory that connects to the
vehicles electrical or vacuum systems. No allowances have been made in the vehicle design for this type of equipment.
Add-on electrical equipment, even when installed to these strict guidelines, may still cause the powertrain system to malfunction. This may also include
equipment not connected to the vehicle electrical system, such as portable telephones and radios. Therefore, the first step in diagnosing any powertrain
condition is to make sure all of the after-market electrical equipment is removed or disconnected from the vehicle. After this has been done and if the
condition still exists, the condition may be diagnosed in the normal manner.
Electrostatic Discharge (ESD) Damage
Note: In order to prevent possible electrostatic discharge damage to the ECM, do not touch the connector pins on the ECM.
The electronic components that are used in the control systems are often designed to carry very low voltage. The electronic components are susceptible
to damage caused by electrostatic discharge. Less than 100 V of static electricity can cause damage to some electronic components. By comparison, it
takes as much as 4 000 V for a person to even feel the zap of a static discharge.
There are several ways for a person to become statically charged. The most common methods of charging are by friction and by induction. An example
of charging by friction is a person sliding across a car seat.
Charging by induction occurs when a person with well insulated shoes stands near a highly charged object and momentarily touches ground. Charges of
the same polarity are drained off leaving the person highly charged with the opposite polarity. Static charges can cause damage, therefore, it is important
to exercise great care when handling and testing electronic components.
Emission Control Information Label
The underhood vehicle emissions control information label contains important emission specifications and setting procedures. This identifies the year,
the manufacturing division of the engine, the displacement of the engine in liters, the class of the vehicle, and type of fuel metering system. There is also
an illustrated emission components and vacuum hose schematic.
This label is located in the engine compartment of every General Motors vehicle. If the label has been removed, it can be ordered from GM service parts
operations (GMSPO).
Underhood Inspection
Note: This inspection is very important and must be done carefully and thoroughly.
Perform a careful underhood inspection when performing any diagnostic procedure or diagnosing the cause of an emission test failure. This can often
lead to repairing a condition without further steps. Use the following guidelines when performing an inspection:
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Inspect all of the vacuum hoses for correct routing, pinches, cuts, or disconnects.
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Inspect any hoses that are difficult to see.
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Inspect all of the wires in the engine compartment for the following conditions:
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Burned or chafed spots
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Pinched wires
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Contact with sharp edges
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Contact with hot exhaust manifolds
Basic Knowledge Required
Caution: Lack of basic knowledge of this powertrain when performing diagnostic procedures could result in incorrect diagnostic performance or
damage to powertrain components. Do not attempt to diagnose a powertrain problem without this basic knowledge.