Onboard Diagnosis (OBD) Tools

Compiled by Abubeker Ali

On Board Diagnosis (OBD)

Definition:- is a generic term referring to a vehicle's self-diagnostic and reporting capability. OBD systems give the vehicle owner or a repair technician access to state of health information for various vehicle sub-systems. The amount of diagnostic information available via OBD has varied widely since the introduction in the early 1980s of on-board vehicle computers, which made OBD possible.

• Early instances of OBD would simply illuminate a malfunction indicator light, or MIL, if a problem was detected—but would not provide any information as to the nature of the problem.

• Modern OBD implementations use a standardized fast digital communications port to provide real-time data in addition to a standardized series of diagnostic trouble codes, or DTCs, which allow one to rapidly identify and remedy malfunctions within the vehicle.

Can /OBD/ Scan Tools Fix Vehicles?

• No• Scan tools are diagnostic tools.• Scan tools are used to gather information about the

vehicle.• The service technician actually fixes the vehicle.

Can the Use of a Scan Tool Damage a Vehicle?

• No.• Care should be taken during certain bi-directional

commands, but generally, a student cannot do harm to a vehicle that could happen with other service procedures.

HISTORY

• 1969: Volkswagen introduces the first on-board computer system with scanning capability, in their fuel-injected Type 3 models.

• 1988: The Society of Automotive Engineers (SAE) recommends a standardized diagnostic connector and set of diagnostic test signals.

• 1996: The OBD-II specification is made mandatory for all cars sold in the United States.

OBD-I

• The regulatory intent of OBD-I was to encourage auto manufacturers to design reliable emission control systems.

• OBD-I was largely unsuccessful as the means of reporting emissions-specific diagnostic information was not standardized. Technical difficulties with obtaining standardized and reliable emissions information from all vehicles led to an inability to implement effectively the annual testing program.

OBD II

• On-Board Diagnostics Second Generation (OBD II) is required for all 1996-and-later vehicles. It is intended to reduce in-use vehicle emissions by continually monitoring all emission control systems and sensors.

• A Malfunction Indicator Light (MIL) (i.e. Check Engine light or Service Engine Soon light) must be illuminated and a Diagnostic Trouble Code (DTC) set when there is a failure of a monitored component such that the vehicle's emissions would exceed the relevant standard by approximately 50 percent.

• The OBD II Scan Tool connects to the vehicle’s OBD II connector and obtains diagnostic information from the vehicle’s computer systems.

• The OBD II Scan Tool enables operations such as reading Diagnostic Trouble Codes, turning off the vehicle’s Check Engine light, real-time sensor data acquisition, and more.

Getting Started• Where is the DLC?• 1996 to 1997 – The DLC had to be visible with the driver’s door

open and the technician in a kneeling position.• 1998 and newer – The DLC can be located almost anywhere and

can be covered.• The cover must not need tools to remove it.

DLC Types Examples on TOYOTA

DLC 1 22 pinsDLC 2 17 pinsDLC 3 16 pins

DLC Locations

Steps in the Diagnostic Process

• Perform a thorough visual inspection.• Check for TSB(tech. service bulletin).• Look carefully at scan tool data (PID or Parameter

Identification).• Narrow the problem to a system or a cylinder.

What Should a Service Technician Do First?

• Verify the customer’s concern.• Check for DTCs.

What Should a Service Technician Do First? (continued)

• Repair the problem and determine the root cause.• Verify the repair and clear all DTCs.

Diagnosis Trouble Codes (DTC)

Why We Use a Scan Tool?

• Is it possible to have a performance complaint with a stored trouble code without having an illuminated check engine light?

• YES!!

Example in terms of using companies' Tec tools(TOYOTA)

Applications

Types and Classifications with Examples

We can categorize auto scanners based on 1. OEM Companies set up TOYOTA-IT2 or TecStream,NISSAN-CONSULT2&3,VW-VAS….etc

2. Automotive system developers creation A scanners capable of scanning different kind of brand vehicles. General Scanners like Launch, AdBlue, AUTOBOSSUK, MAXIDAS…..etc

Thank You!