Actron 9640 User Manual

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.

SMEC Single Module Engine 

Controller

1989–1990

Used a 6-pin Serial Communication Interface (SCI) 

DLC and has bidirectional capability.

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 Powertrain 

Control Module

1995**– present Complies with OBD II regulations and uses the OBD II 

J1962 DLC. 

Complies with OBD II regulations and uses the OBD II 

Jeeps