Express 2500 V8-6.6L DSL Turbo (2010)
stores a DTC that is associated with the condition.
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
vehicle's 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 eliminate all of the aftermarket electrical equipment from the vehicle. After this is done, if the problem still exists, the problem 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. These 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 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 use care when handling and testing electronic components.
Emissions Control Information Label
The underhood Vehicle Emissions Control Information Label contains important emission specifications and setting procedures. In the upper left corner
is the exhaust emission information. 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.
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).
VIN 6
Engine Control Module Description
The powertrain has electronic controls to reduce exhaust emissions while maintaining excellent driveability and fuel economy. The engine control
module (ECM) is the control center of this system. The ECM monitors numerous engine and vehicle functions. The ECM constantly monitors
information from various sensors and other inputs, and controls the systems that affect vehicle performance and emissions. The ECM also performs
diagnostic tests on various parts of the system. The ECM can recognize operational problems and alert the driver via the malfunction indicator lamp
(MIL). When the ECM detects a malfunction, the ECM stores a diagnostic trouble code (DTC). The problem area is identified by the particular DTC
that is set. The control module supplies a buffered voltage to various sensors and switches. Review the components and wiring diagrams in order to
determine which systems are controlled by the ECM.
Malfunction Indicator Lamp (MIL) Operation
The malfunction indicator lamp (MIL) is located in the instrument panel cluster. The MIL will display as either SERVICE ENGINE SOON or one of the
following symbols when commanded ON:
