King Tool CanScan D900 User manual

CanScan
OWNER’S
MANUAL
The Easiest
And Best Way
To Troubleshoot
1996 and
Newer OBD2
Vehicles!

Table of Contents
Introduction...................................................................................................................................2
You Can Do It!...............................................................................................................................3
Safety Precautions.......................................................................................................................4
SAFETY FIRST!............................................................................................................................4
About the CanScan......................................................................................................................6
VEHICLES COVERED.................................................................................................................6
BATTERY REPLACEMENT..........................................................................................................7
ADJUSTMENTS AND SETTINGS................................................................................................7
CanScan Controls........................................................................................................................9
CONTROLS AND INDICATORS ..................................................................................................9
DISPLAY FUNCTIONS...............................................................................................................11
Onboard Diagnostics................................................................................................................12
COMPUTER ENGINE CONTROLS...........................................................................................12
OBD 2 Terminology....................................................................................................................16
DIAGNOSTIC TROUBLE CODES (DTCs) ................................................................................18
Preparation for Testing.............................................................................................................20
BEFORE YOU BEGIN................................................................................................................20
Using the CanScan....................................................................................................................21
CODE RETRIEVAL PROCEDURE............................................................................................21
ERASING DIAGNOSTIC TROUBLE CODES (DTCs)...............................................................27
D900 CanScan 1

Introduction
WHAT IS OBD?
Introduction
WHAT IS OBD?
The D900 CanScan is designed to work on all OBD 2 compliant vehicles.
All 1996 and newer vehicles (cars, light trucks and SUVs) sold in the
United States are OBD 2 compliant.
One of the most exciting improvements in
the automobile industry was the addition of
on-board diagnostics (OBD) on vehicles, or
in more basic terms, the computer that
activates the vehicle’s “CHECK ENGINE”
light. OBD 1 was designed to monitor
manufacturer-specific systems on vehicles
built from 1981 to 1995. Then came the
development of OBD 2, which is on all 1996
and newer vehicles sold in the U.S. Like its predecessor, OBD 2 was adopted
as part of a government mandate to lower vehicle emissions. But what makes
OBD 2 unique is its universal application for all late model cars and trucks –
domestic and import. This sophisticated program in the vehicle’s main
computer system is designed to detect failures in a range of systems, and can
be accessed through a universal OBD 2 port, which is usually found under the
dashboard. For all OBD systems, if a problem is found, the computer turns on
the “CHECK ENGINE” light to warn the driver, and sets a Diagnostic Trouble
Code (DTC) to identify where the problem occurred. A special diagnostic tool,
such as the D900 CanScan, is required to retrieve these codes, which
consumers and professionals use as a starting point for repairs.
D900 CanScan 2
To learn more about vehicle Computer Control Systems and OBD 2,
see COMPUTER ENGINE CONTROLS on page 12.

You Can Do It!
EASY TO USE - EASY TO VIEW
You Can Do It!
Easy To Use ....
¾Connect the CanScan to the vehicle’s test
connector.
¾Turn the ignition key "On.”
¾Press the LINK button.
Easy To View ....
¾The CanScan retrieves stored codes,
Freeze Frame data and I/M Readiness
status.
¾Codes, I/M Readiness status and Freeze
Frame data are displayed on the
CanScan’s LCD display screen. System
status is indicated by LED indicators.
Easy To Define ....
¾Read code definitions from the
CanScan’s LCD display.
¾View Freeze Frame data.
D900 CanScan 3

Safety Precautions
SAFETY FIRST!
Safety Precautions
SAFETY FIRST!
This manual describes common test procedures used by
experienced service technicians. Many test procedures require
precautions to avoid accidents that can result in personal injury,
and/or damage to your vehicle or test equipment. Always read your
vehicle's service manual and follow its safety precautions before and
during any test or service procedure. ALWAYS observe the following
general safety precautions:
To avoid personal injury, instrument damage and/or damage to
your vehicle; do not use the CAN OBD2 Code Reader before
reading this manual.
When an engine is running, it produces carbon monoxide, a
toxic and poisonous gas. To prevent serious injury or death
from carbon monoxide poisoning, operate the vehicle ONLY
in a well-ventilated area.
To protect your eyes from propelled objects as well as hot
or caustic liquids, always wear approved safety eye
protection.
When an engine is running, many parts (such as the coolant
fan, pulleys, fan belt etc.) turn at high speed. To avoid
serious injury, always be aware of moving parts. Keep a
safe distance from these parts as well as other potentially
moving objects.
Engine parts become very hot when the engine is running.
To prevent severe burns, avoid contact with hot engine
parts.
Before starting an engine for testing or trouble-shooting,
make sure the parking brake is engaged. Put the
transmission in park (for automatic transmission) or neutral
(for manual transmission). Block the drive wheels with
suitable blocks.
Connecting or disconnecting test equipment when the
ignition is ON can damage test equipment and the vehicle's
electronic components. Turn the ignition OFF before
connecting the CanScan to or disconnecting the CanScan
from the vehicle’s Data Link Connector (DLC).
D900 CanScan 4

Safety Precautions
SAFETY FIRST!
To prevent damage to the on-board computer when taking
vehicle electrical measurements, always use a digital
multimeter with at least 10 megOhms of impedance.
Fuel and battery vapors are highly flammable. To pre-vent
an explosion, keep all sparks, heated items and open
flames away from the battery and fuel / fuel vapors. DO
NOT SMOKE NEAR THE VEHICLE DUR-ING TESTING.
Don't wear loose clothing or jewelry when working on an
engine. Loose clothing can become caught in the fan,
pulleys, belts, etc. Jewelry is highly conductive, and can
cause a severe burn if it makes contact between a power
source and ground.
D900 CanScan 5

About the Code Reader
VEHICLES COVERED / BATTERY REPLACEMENT
About the CanScan
VEHICLES COVERED
The D900 CanScan is designed to work on all OBD 2 compliant vehicles. All
1996 and newer vehicles (cars and light trucks) sold in the United States are
OBD 2 compliant.
Federal law requires that all 1996 and newer cars and light trucks
sold in the United States must be OBD 2 compliant; this includes all
Domestic, Asian and European vehicles.
Some 1994 and 1995 vehicles are OBD 2 compliant. To find out if a 1994 or
1995 vehicle is OBD 2 compliant, check the following:
1. The Vehicle Emissions Control Information (VECI) Label. This label is
located under the hood or by the radiator of most vehicles. If the vehicle is
OBD 2 compliant, the label will state “OBD II Certified.”
2. Government Regulations require that all
OBD 2 compliant vehicles must have a
“common” sixteen-pin Data Link Connector
(DLC).
Some 1994 and 1995 vehicles have 16-pin connectors but are not
OBD 2 compliant. Only those vehicles with a Vehicle Emissions
Control Label stating “OBD II Certified” are OBD 2 compliant.
D900 CanScan 6

About the Code Reader
VEHICLES COVERED / BATTERY REPLACEMENT
Data Link Connector (DLC) Location
The 16-pin DLC is usually located under the
instrument panel (dash), within 12 inches
(300 mm) of center of the panel, on the
driver’s side of most vehicles. It should be
easily accessible and visible from a kneeling
position outside the vehicle with the door
open.
On some Asian and European vehicles the DLC is located behind
the “ashtray” (the ashtray must be removed to access it) or on the
far left corner of the dash. If the DLC cannot be located, consult the
vehicle’s service manual for the location.
BATTERY REPLACEMENT
1. Locate the battery cover on the back of the CanScan.
2. Slide the battery cover off (use your fingers).
3. Replace batteries with three AA-size batteries (for longer life, use
Alkaline-type batteries).
4. Reinstall the battery cover on the back of the CanScan.
ADJUSTMENTS AND SETTINGS
To enter the MENU Mode:
1. Press and hold the UP button, then press
and release the POWER/LINK button.
¾The adjustments and setting MENU
displays.
2. DO NOT release the UP button until the
adjustments and settings MENU is visible on
the display.
3. Make adjustments and settings as described in the following paragraphs.
D900 CanScan 7

About the Code Reader
VEHICLES COVERED / BATTERY REPLACEMENT
Adjusting Display Brightness
1. Use the UP and DOWN buttons, as
necessary, to highlight Adjust Brightness in
the MENU, then press the ENTER/FF
button.
¾The Adjust Brightness screen displays.
¾The Brightness field shows the current
brightness setting, from 1 to 10.
2. Press the UP button to decrease the brightness of the LCD display (make
the display darker)
3. Press the DOWN button to increase the brightness of the LCD display
(make the display lighter).
4. When the desired brightness is obtained, press the ENTER/FF button to
save your changes and return to the MENU.
Exiting the MENU Mode
1. Use the UP and DOWN buttons, as necessary, to highlight Menu Exit
in the MENU, then press the ENTER/FF button.
¾The LCD display returns to the DTC screen.
Changes made to Brightness will remain in the CanScan’s memory
as long as the batteries are not removed. If the batteries are
removed (or go dead), the settings will be lost from the CanScan’s
memory, and they must be reset again.
D900 CanScan 8

Code Reader Controls
CONTROLS AND INDICATORS
CanScan Controls
CONTROLS AND INDICATORS
Figure 1. Controls and Indicators
See Figure 1 for the locations of items 1 through 11, below.
1. ERASE button - Erases Diagnostic Trouble Codes (DTCs), and
“Freeze Frame” data from your vehicle’s computer, and resets Monitor status.
2. DTC SCROLL button - Displays the DTC View screen and/or scrolls
the LCD display to view DTCs when more than one DTC is present.
3. POWER/LINK button - When the CanScan IS NOT connected to a
vehicle, turns the CanScan “On” and “Off”. When the CanScan is connected
to a vehicle, links the CanScan to the vehicle’s PCM to retrieve diagnostic data
from the computer’s memory.
4. ENTER/FREEZE FRAME button - When in MENU mode, confirms
the selected option or value. When retrieving and viewing DTCs, displays
Freeze Frame data for the highest priority code.
D900 CanScan 9

Code Reader Controls
CONTROLS AND INDICATORS
5. DOWN button - When in MENU mode, scrolls DOWN through the
menu and submenu selection options. When retrieving and viewing DTCs,
scrolls down through the current display screen to display any additional data.
6. UP button - When in MENU mode, scrolls UP through the menu and
submenu selection options. When retrieving and viewing DTCs, scrolls ups
through the current display screen to display any additional data.
7. GREEN LED - Indicates that all engine systems are running normally (all
Monitors on the vehicle are active and performing their diagnostic testing, and
no DTCs are present).
8. YELLOW LED - Indicates there is a possible problem. A “Pending” DTC is
present and/or some of the vehicle’s emission monitors have not run their
diagnostic testing.
9. RED LED - Indicates there is a problem in one or more of the vehicle’s
systems. The red LED is also used to show that DTC(s) are present. DTCs are
shown on the CanScan’s LCD display. In this case, the Multifunction Indicator
(“Check Engine”) lamp on the vehicle’s instrument panel will light steady on.
10. LCD Display - Displays settings Menu and submenus, test results,
CanScan functions. See DISPLAY FUNCTIONS, on next page, for more
details.
11. CABLE - Connects the CanScan to the vehicle’s Data Link Connector
(DLC).
D900 CanScan 10

Code Reader Controls
DISPLAY FUNCTIONS
DISPLAY FUNCTIONS
Figure 2. Display Functions
See Figure 2 for the locations of items 1 through 6, below.
1. Test Data Display Area - Displays DTC definitions, and other pertinent test
information messages.
2. DTC Display Area - Displays the Diagnostic Trouble Code (DTC) number.
Each fault is assigned a code number that is specific to that fault.
3. Code Number Sequence - The CanScan assigns a sequence number to
each DTC that is present in the computer’s memory, starting with “1.” This
number indicates which code is currently displayed. Code number “1” is
always the highest priority code.
4. Code Enumerator - Indicates the total number of codes retrieved from the
vehicle’s computer.
5. Vehicle icon / Link icon / Internal Battery icon
Vehicle icon - Indicates whether or not the CanScan is being properly
powered through the vehicle’s Data Link Connector (DLC). A visible icon
indicates that the CanScan is being powered through the vehicle’s DLC
connector.
Link icon - Indicates whether or not the CanScan is communicating
(linked) with the vehicle’s on-board computer. When visible, the CanScan is
communicating with the computer. If the Link icon is not visible, the CanScan is
not communicating with the computer.
CanScan Internal Battery icon - When visible, indicates the CanScan
batteries are “low” and should be replaced.
6. PENDING icon - Indicates the currently displayed DTC is a “Pending” code.
D900 CanScan 11

Onboard Diagnostics
DIAGNOSTIC TROUBLE CODES (DTCs)
Onboard Diagnostics
COMPUTER ENGINE CONTROLS
The Introduction of Electronic Engine Controls
As a result of increased air pollution (smog) in large cities, such as Los
Angeles, the California Air Resources Board (CARB) and the
Environmental Protection Agency (EPA) set new regulations and air
pollution standards to deal with the problem. To further complicate matters,
the energy crisis of the early 1970s caused a sharp increase in fuel prices
over a short period. As a result, vehicle manufacturers were not only
required to comply with the new emissions standards, they also had to make
their vehicles more fuel-efficient. Most vehicles were required to meet a
miles-per-gallon (MPG) standard set by the U.S. Federal Government.
Electronic Computer Control Systems make it possible for
vehicle manufacturers to comply with the tougher emissions and
fuel efficiency standards mandated by State and Federal
G
Precise fuel delivery and spark timing are needed to reduce vehicle emissions.
Mechanical engine controls in use at the time (such as ignition points,
mechanical spark advance and the carburetor) responded too slowly to driving
conditions to properly control fuel delivery and spark timing. This made it
difficult for vehicle manufacturers to meet the new standards.
A new Engine Control System had to be designed and integrated with the
engine controls to meet the stricter standards. The new system had to:
¾Respond instantly to supply the proper mixture of air and fuel for any
driving condition (idle, cruising, low-speed driving, high-speed driving,
etc.).
¾Calculate instantly the best time to “ignite” the air/fuel mixture for maximum
engine efficiency.
¾Perform both these tasks without affecting vehicle performance or fuel
economy.
Vehicle Computer Control Systems can perform millions of calculations each
second. This makes them an ideal substitute for the slower mechanical engine
controls. By switching from mechanical to electronic engine controls, vehicle
manufacturers are able to control fuel delivery and spark timing more precisely.
Some newer Computer Control Systems also provide control over other
vehicle functions, such as transmission, brakes, charging, body, and
suspension systems.
D900 CanScan 12

Onboard Diagnostics
DIAGNOSTIC TROUBLE CODES (DTCs)
The Basic Engine Computer Control System
The Computer Control System consists of an on-board computer
and several related control devices (sensors, switches, and
actuators).
The on-board computer is the heart of the Computer Control System. The
computer contains several programs with preset reference values for air/fuel
ratio, spark or ignition timing, injector pulse width, engine speed, etc. Separate
values are provided for various driving conditions, such as idle, low speed
driving, high-speed driving, low load, or high load. The preset reference values
represent the ideal air/fuel mixture, spark timing, transmission gear selection,
etc., for any driving condition. These values are programmed by the vehicle
manufacturer, and are specific to each vehicle model.
Most on-board computers are located inside the vehicle behind the dashboard,
under the passenger’s or driver’s seat, or behind the right kick panel. However,
some manufacturers may still position it in the engine compartment.
Vehicle sensors, switches, and actuators are located throughout the engine,
and are connected by electrical wiring to the on-board computer. These
devices include oxygen sensors, coolant temperature sensors, throttle position
sensors, fuel injectors, etc. Sensors and switches are input devices. They
provide signals representing current engine operating conditions to the
computer. Actuators are output devices. They perform actions in response to
commands received from the computer.
The on-board computer receives information inputs from sensors and switches
located throughout the engine. These devices monitor critical engine
conditions such as coolant temperature, engine speed, engine load, throttle
position, air/fuel ratio etc.
D900 CanScan 13

Onboard Diagnostics
DIAGNOSTIC TROUBLE CODES (DTCs)
The computer compares the values received from these sensors with its preset
reference values, and makes corrective actions as needed so that the sensor
values always match the preset reference values for the current driving
condition. The computer makes adjustments by commanding other devices
such as the fuel injectors, idle air control, EGR valve or Ignition Module to
perform these actions.
Vehicle operating conditions are constantly changing. The computer
continuously makes adjustments or corrections (especially to the air/fuel
mixture and spark timing) to keep all the engine systems operating within the
preset reference values.
On-Board Diagnostics - First Generation (OBD 1)
Beginning in 1988, California’s Air Resources Board (CARB), and
later the Environmental Protection Agency (EPA) required vehicle
manufacturers to include a self-diagnostic program in their on-board
computers. The pro-gram would be capable of identifying
emissions-related faults in a system. The first generation of Onboard
Diagnostics came to be known as OBD 1.
The Computer Control System consists of an on-board computer
and several related control devices (sensors, switches, and
actuators).
OBD 1 is a set of self-testing and diagnostic instructions programmed into the
vehicle’s on-board computer. The programs are specifically designed to detect
failures in the sensors, actuators, switches and wiring of the various vehicle
missions-related systems. If the computer detects a failure in any of these
components or systems, it lights an indicator on the dashboard to alert the
driver. The indicator lights only when an emissions-related problem is
detected.
The computer also assigns a numeric code for each specific problem that it
detects, and stores these codes in its memory for later retrieval. These codes
can be retrieved from the computer’s memory with the use of a “CanScan” or a
“Scan Tool.”
D900 CanScan 14

Onboard Diagnostics
DIAGNOSTIC TROUBLE CODES (DTCs)
On-Board Diagnostics - Second Generation (OBD 2)
The OBD 2 System is
an enhancement of the
OBD 1 System.
In addition to performing all the functions
of the OBD 1 System, the OBD 2 System
has been enhanced with new Diagnostic
Programs. These programs closely
monitor the functions of various
emissions-related components and systems (as well as other systems)
and make this information readily available (with the proper equipment)
to the technician for evaluation.
The California Air Resources Board (CARB) conducted studies on
OBD 1 equipped vehicles. The information that was gathered from
these studies showed the following:
¾A large number of vehicles had deteriorating or degraded
emissions-related components. These components were causing an
increase in emissions.
¾Because OBD 1 systems only detect failed components, the degraded
components were not setting codes.
¾Some emissions problems related to degraded components only occur
when the vehicle is being driven under a load. The emission checks being
conducted at the time were not performed under simulated driving
conditions. As a result, a significant number of vehicles with degraded
components were passing Emissions Tests.
¾Codes, code definitions, diagnostic connectors, communication protocols
and emissions terminology were different for each manufacturer. This
caused confusion for the technicians working on different make and model
vehicles.
To address the problems made evident by this study, CARB and the EPA
passed new laws and standardization requirements. These laws required that
vehicle manufacturers to equip their new vehicles with devices capable of
meeting all of the new emissions standards and regulations. It was also
decided that an enhanced on-board diagnostic system, capable of addressing
all of these problems, was needed. This new system is known as “On-Board
Diagnostics Generation Two (OBD 2).” The primary objective of the OBD 2
system is to comply with the latest regulations and emissions standards
established by CARB and the EPA.
The Main Objectives of the OBD 2 System are:
¾To detect degraded and/or failed emissions-related components or
systems that could cause tailpipe emissions to exceed by 1.5 times the
Federal Test Procedure (FTP) standard.
D900 CanScan 15

Onboard Diagnostics
DIAGNOSTIC TROUBLE CODES (DTCs)
¾To expand emissions-related system monitoring. This includes a set of
computer run diagnostics called Monitors. Monitors perform diagnostics
and testing to verify that all emissions-related components and/or systems
are operating correctly and within the manufacturer’s specifications.
¾To use a standardized Diagnostic Link Connector (DLC) in all vehicles.
(Before OBD 2, DLCs were of different shapes and sizes.)
¾To standardize the code numbers, code definitions and language used to
describe faults. (Before OBD 2, each vehicle manufacturer used their own
code numbers, code definitions and language to describe the same faults.)
¾To expand the operation of the Malfunction Indicator Lamp (MIL).
¾To standardize communication procedures and protocols between the
diagnostic equipment (Scan Tools, CanScans, etc.) and the vehicle’s
on-board computer.
OBD 2 Terminology
The following terms and their definitions are related to OBD 2 systems. Read
and reference this list as needed to aid in the understanding of OBD 2
systems.
¾Powertrain Control Module (PCM) - The PCM is the OBD 2 accepted
term for the vehicle’s “on-board computer.” In addition to controlling the
engine management and emissions systems, the PCM also participates in
controlling the powertrain (transmission) operation. Most PCMs also have
the ability to communicate with other computers on the vehicle (ABS, ride
control, body, etc.).
¾Monitor - Monitors are “diagnostic routines” programmed into the PCM.
The PCM utilizes these programs to run diagnostic tests, and to monitor
operation of the vehicle’s emissions-related components or systems to
ensure they are operating correctly and within the vehicle’s manufacturer
specifications. Currently, up to eleven Monitors are used in OBD 2 systems.
Additional Monitors will be added as the OBD 2 system is further
developed.
Not all vehicles support all eleven Monitors.
D900 CanScan 16
¾Enabling Criteria - Each Monitor is designed to test and monitor the
operation of a specific part of the vehicle’s emissions system (EGR system,
oxygen sensor, catalytic converter, etc.). A specific set of “conditions” or
“driving procedures” must be met before the computer can command a
Monitor to run tests on its related system. These “conditions” are known as

Onboard Diagnostics
DIAGNOSTIC TROUBLE CODES (DTCs)
“Enabling Criteria.” The requirements and procedures vary for each
Monitor. Some Monitors only require the ignition key to be turned “On” for
them to run and complete their diagnostic testing. Others may require a set
of complex procedures, such as, starting the vehicle when cold, bringing it
to operating temperature, and driving the vehicle under specific conditions
before the Monitor can run and complete its diagnostic testing.
¾Monitor Has/Has Not Run - The terms “Monitor has run” or “Monitor has
not run” are used throughout this manual. “Monitor has run,” means the
PCM has commanded a particular Monitor to perform the required
diagnostic testing on a system to ensure the system is operating correctly
(within factory specifications). The term “Monitor has not run” means the
PCM has not yet commanded a particular Monitor to perform diagnostic
testing on its associated part of the emissions system.
¾Trip - A Trip for a particular Monitor requires that the vehicle is being
driven in such a way that all the required “Enabling Criteria” for the Monitor
to run and complete its diagnostic testing are met. The “Trip Drive Cycle”
for a particular Monitor begins when the ignition key is turned “On.” It is
successfully completed when all the “Enabling Criteria” for the Monitor to
run and complete its diagnostic testing are met by the time the ignition key
is turned “Off.” Since each of the eleven monitors is designed to run
diagnostics and testing on a different part of the engine or emissions
system, the “Trip Drive Cycle” needed for each individual Monitor to run
and complete varies.
¾OBD 2 Drive Cycle - An OBD 2 Drive Cycle is an extended set of driving
procedures that takes into consideration the various types of driving
conditions encountered in real life. These conditions may include starting
the vehicle when it is cold, driving the vehicle at a steady speed (cruising),
accelerating, etc. An OBD 2 Drive Cycle begins when the ignition key is
turned “On” (when cold) and ends when the vehicle has been driven in
such a way as to have all the “Enabling Criteria” met for all its applicable
Monitors. Only those trips that provide the Enabling Criteria for all Monitors
applicable to the vehicle to run and complete their individual diagnostic
tests qualify as an OBD 2 Drive Cycle. OBD 2 Drive Cycle requirements
vary from one model of vehicle to another. Vehicle manufacturers set
these procedures. Consult your vehicle’s service manual for OBD 2 Drive
Cycle procedures.
Do not confuse a “Trip” Drive Cycle with an OBD 2 Drive Cycle. A
“Trip” Drive Cycle provides the “Enabling Criteria” for one specific
Monitor to run and complete its diagnostic testing. An OBD 2 Drive
Cycle must meet the “Enabling Criteria” for all Monitors on a
particular vehicle to run and complete their diagnostic testing.
D900 CanScan 17
¾Warm-up Cycle - Vehicle operation after an engine off period where
engine temperature rises at least 40°F (22°C) from its temperature before
starting, and reaches at least 160°F (70°C). The PCM uses warm-up

Onboard Diagnostics
DIAGNOSTIC TROUBLE CODES (DTCs)
cycles as a counter to automatically erase a specific code and related data
from its memory. When no faults related to the original problem are
detected within a specified number of warm-up cycles, the code is erased
automatically.
DIAGNOSTIC TROUBLE CODES (DTCs)
Diagnostic Trouble
Codes (DTCs) are
codes that identify a
specific problem area.
Diagnostic Trouble Codes (DTCs) are meant
to guide you to the proper service procedure
in the vehicle’s service manual. DO NOT
replace parts based only on DTCs without
first consulting the vehicle’s service manual
for proper testing procedures for that
particular system, circuit or component. DTCs
are alphanumeric codes that are used to identify a problem that is
present in any of the systems that are monitored by the on-board
computer (PCM). Each trouble code has an assigned message that
identifies the circuit, component or system area where the problem was
found.
OBD 2 diagnostic trouble codes are made up of five characters:
¾The 1st character is a letter. It identifies the “main system” where the fault
occurred (Body, Chassis, Powertrain, or Network).
¾The 2nd character is a numeric digit. It identifies the “type” of code
(Generic or Manufacturer-Specific).
Generic DTCs are codes that are used by all vehicle manufacturers.
The standards for generic DTCs, as well as their definitions, are set
by the Society of Automotive Engineers (SAE).
Manufacturer-Specific DTCs are codes that are controlled by the
vehicle manufacturers. The Federal Government does not require
vehicle manufacturers to go beyond the standardized generic DTCs
in order to comply with the new OBD2 emissions standards.
However, manufacturers are free to expand beyond the
standardized codes to make their systems easier to diagnose.
¾The 3rd character is a numeric digit. It identifies the specific sys-tem or
sub-system where the problem is located.
¾The 4th and 5th characters are numeric digits. They identify the section of
the system that is malfunctioning.
D900 CanScan 18

Onboard Diagnostics
DIAGNOSTIC TROUBLE CODES (DTCs)
BD 2 DTC EXAMPLE
P0201 - Injector Circuit Malfunction, Cylinder 1
D900 CanScan 19