Actron KAL9640B - Manual (Page 17)

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Getting Started
2
OBD II stands for On-Board Diagnostics version II. OBD II is a system that the
Society of Automotive Engineers (SAE) developed to standardize automotive
electronic diagnosis. Technicians now can use the same tool to test any OBD
II compliant vehicles without special adapters. The SAE established guidelines
that provide:
• a universal diagnostic test connector, called the data link connector (DLC),
with dedicated pin assignments.
• a standardized location for the DLC, visible under the dash on the driver’s
side.
• a standardized list of diagnostic trouble codes (DTCs) used by all
manufacturers.
• a standardized list of parameter identification (PID) data used by all
manufacturers.
• the ability of the vehicle system to record a freeze frame of the operating
conditions when a fault occurs.
• expanded diagnostic capabilities that records a code whenever a condition
occurs that effects vehicle emissions.
• the ability to clear stored codes from vehicle memory with the scan tool.
In addition, SAE has published hundreds of pages of text defining a standard
communications protocol that establishes the hardware, software, and circuit
parameters of OBD II systems. Unfortunately, vehicle manufacturers have
different interpretations of this standard communications protocol. As a result,
the generic OBD II communications scheme used will vary, depending on the
vehicle.
Chrysler On-Board Diagnostics
System Long Name Years Description
SMEC Single Module Engine
Controller
1989–1990
Used a 6-pin Serial Communication Interface (SCI)
DLC and has bidirectional capability.
SBEC
Single Board Engine
Controller
1989*–1995
Used two types of DLCs: a 6-pin SCI and a 6-pin LH
series.
The first to allow a tool to reset the EMR light on trucks.
OBD II
PCM
OBD II Powertrain
Control Module
1995**– present Complies with OBD II regulations and uses the OBD II
J1962 DLC.
JTEC
Jeep/Truck Engine
Controller
1996– present
Complies with OBD II regulations and uses the OBD II
J1962 DLC.
The JTEC system is used on light-duty trucks and
Jeeps
* In 1989, the SBEC system was installed in selected vehicles with 3.0L V6 engines.
** Some vehicles in 1995 were equipped with the OBD II PCM.