Autel Autolink AL539B User manual

Table of Contents
1. SAFETY PRECAUTIONS AND WARNINGS............................................1
2. GENERAL INFORMATION......................................................................2
2.1 ON-BOARD DIAGNOSTICS (OBD)II...........................................................2
2.2 DIAGNOSTIC TROUBLE CODES (DTCS)......................................................2
2.3 LOCATION OF THE DATA LINK CONNECTOR (DLC)...................................3
2.4 OBDII READINESS MONITORS .................................................................4
2.5 OBDIIMONITOR READINESS STATUS ......................................................5
2.6 OBDII DEFINITIONS ................................................................................6
2.7 OBDIIMODES OF OPERATION .................................................................7
3. USING THE SCAN TOOL........................................................................10
3.1 TOOL DESCRIPTION ................................................................................10
3.2 SPECIFICATIONS .....................................................................................12
3.3 ACCESSORIES INCLUDED......................................................................... 13
3.4 NAVIGATION CHARACTERS .....................................................................13
3.5 KEYBOARD .............................................................................................13
3.6 POWER AND CHARGE...............................................................................14
3.7 DTCLOOKUP.........................................................................................16
3.8 SYSTEM SETUP........................................................................................17
3.9 VEHICLE COVERAGE...............................................................................27
3.10 PRODUCT TROUBLESHOOTING ................................................................28
4. REVIEW DATA.........................................................................................30
5. OBDII DIAGNOSTICS..............................................................................31
5.1 READING CODES.....................................................................................33
5.2 ERASING CODES...................................................................................... 35
5.3 LIVE DATA .............................................................................................37
5.4 VIEWING FREEZE FRAME DATA ..............................................................49
5.5 RETRIEVING I/MREADINESS STATUS ......................................................50

5.6 O2MONITOR TEST ................................................................................. 56
5.7 ON-BOARD MONITOR TEST.....................................................................58
5.8 COMPONENT TEST .................................................................................. 61
5.9 VIEWING VEHICLE INFORMATION ...........................................................63
5.10 MODULES PRESENT.................................................................................65
6. READY TEST............................................................................................66
6.1 GENERAL INFORMATION.........................................................................66
6.2 READY TEST APPLICATION ......................................................................67
6.3 LEDAND TONE INTERPRETATION...........................................................69
7. CIRCUIT TEST FUNCTION....................................................................71
7.1 AUTO ...........................................................................................71
7.2 DC VOLTAGE ................................................................................71
7.3 AC VOLTAGE ...............................................................................72
7.4 CONTINUITY .................................................................................. 72
7.5 DIODES ..........................................................................................73
7.6 CURRENT ......................................................................................74
7.7 CURRENT ......................................................................................74
8. START TEST.............................................................................................76
8.1 STARTER TEST ...............................................................................76
8.2 CHARGING SYSTEM TEST ............................................................. 81
9. BATTERY TEST - ONLY FOR AL539B..................................................85
10. PRINT DATA.............................................................................................89
11. WARRANTY AND SERVICE...................................................................91
11.1 LIMITED ONE YEAR WARRANTY.............................................................91
11.2 SERVICE PROCEDURES............................................................................91

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1. Safety Precautions and Warnings
To prevent personal injury or damage to vehicles and/or the scan
tool, read this instruction manual first and observe the following
safety precautions at a minimum whenever working on a vehicle:
Always perform automotive testing in a safe environment.
Wear safety eye protection that meets ANSI standards.
Keep clothing, hair, hands, tools, test equipment, etc. away from
all moving or hot engine parts.
Operate the vehicle in a well ventilated work area: Exhaust gases
are poisonous.
Put blocks in front of the drive wheels and never leave the vehicle
unattended while running tests.
Use extreme caution when working around the ignition coil,
distributor cap, ignition wires and spark plugs. These
components create hazardous voltages when the engine is
running.
Put the transmission in PARK (for automatic transmission) or
NEUTRAL (for manual transmission) and make sure the parking
brake is engaged.
Keep a fire extinguisher suitable for gasoline/chemical/ electrical
fires nearby.
Don’t connect or disconnect any test equipment while the
ignition is on or the engine is running.
Keep the scan tool dry, clean, free from oil/water or grease. Use a
mild detergent on a clean cloth to clean the outside of the scan
tool, when necessary.

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2. General Information
2.1 On-Board Diagnostics (OBD) II
The first generation of On-Board Diagnostics (called OBD I) was
developed by the California Air Resources Board (ARB) and
implemented in 1988 to monitor some of the emission control
components on vehicles. As technology evolved and the desire to
improve the On-Board Diagnostic system increased, a new generation
of On-Board Diagnostic systemwas developed. This second generation
of On-Board Diagnostic regulations is called "OBD II".
The OBD II system is designed to monitor emission control systems
and key engine components by performing either continuous or
periodic tests of specific components and vehicle conditions. When a
problem is detected, the OBD II system turns ona warning lamp (MIL)
on the vehicle instrument panel to alert the driver typically by the
phrase of “Check Engine” or “Service Engine Soon”. The system will
also store important information about the detected malfunction so
that a technician can accurately find and fix the problem. Here below
follow three pieces of such valuable information:
1) Whether the Malfunction Indicator Light (MIL) is
commanded 'on' or 'off';
2) Which, if any, Diagnostic Trouble Codes (DTCs) are stored;
3) Readiness Monitor status.
2.2 Diagnostic Trouble Codes (DTCs)
OBD II Diagnostic Trouble Codes are codes that are stored by the
on-board computer diagnostic system in response to a problem found
in the vehicle. These codes identify a particular problem area and are
intended to provide you with a guide as to where a fault might be
occurring within a vehicle. OBD II Diagnostic Trouble Codes
consists of a five-digit alphanumeric code. The first character, a letter,
identifies which control system sets the code. The other four
characters, all numbers, provide additional information on where the
DTC originated and the operating conditions that caused it to set. Here
below is an example to illustrate the structure of the digits:

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2.3 Location of the Data Link Connector (DLC)
The DLC (Data Link Connector or Diagnostic Link Connector) is the
standardized 16-cavity connector where diagnostic scan tools
interface with the vehicle's on-board computer. The DLC is usually
located 12 inches from the center of the instrument panel (dash),
under or around the driver’s side for most vehicles. If Data Link
Connector is not located under dashboard, a label should be there
telling location. For some Asian and European vehicles, the DLC is
located behind the ashtray and the ashtray must be removed to access
the connector. If the DLC cannot be found, refer to the vehicle’s
service manual for the location.

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2.4 OBD II Readiness Monitors
An important part of a vehicle’s OBD II system is the Readiness
Monitors, which are indicators used to find out if all of the emissions
components have been evaluated by the OBD II system. They are
running periodic tests on specific systems and components to ensure
that they are performing within allowable limits.
Currently, there are eleven OBD II Readiness Monitors (or I/M
Monitors) defined by the U.S. Environmental Protection Agency
(EPA). Not all monitors are supported by all vehicles and the exact
number of monitors in any vehicle depends on the motor vehicle
manufacturer’s emissions control strategy.
Continuous Monitors -- Some of the vehicle components or systems
are continuously tested by the vehicle’s OBD II system, while others
are tested only under specific vehicle operating conditions. The
continuously monitored components listed below are always ready:
1）Misfire
2）Fuel System
3）Comprehensive Components (CCM)
Once the vehicle is running, the OBD II system is continuously
checking the above components, monitoring key engine sensors,
watching for engine misfire, and monitoring fuel demands.
Non-Continuous Monitors -- Unlike the continuous monitors, many
emissions and engine system components require the vehicle to be
operated under specific conditions before the monitor is ready. These

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monitors are termed non-continuous monitors. For different ignition
type engines, the available monitors are different too.
The following monitors are to be used for spark ignition engines
only:
1) EGR System
2) O2 Sensors
3) Catalyst
4) Evaporative System
5) O2 Sensor Heater
6) Secondary Air
7) Heated Catalyst
The following monitors are to be used for compression ignition
engines only:
1) EGR System
2) NMHC Catalyst
3) NOx Aftertreatment
4) Boost Pressure System
5) Exhaust Gas Sensor
6) PM Filter
2.5 OBD II Monitor Readiness Status
OBD II systems must indicate whether or not the vehicle’s PCM’s
monitor system has completed testing on each component.
Components that have been tested will be reported as “Ready”, or
“Complete”, meaning they have been tested by the OBD II system.
The purpose of recording readiness status is to allow inspectors to
determine if the vehicle’s OBD II system has tested all the
components and/or systems.
The power-train control module (PCM) sets a monitor to “Ready” or
“Complete” after an appropriate drive cycle has been performed. The
drive cycle that enables a monitor and sets readiness codes to “Ready”
varies for each individual monitor. Once a monitor is set as “Ready”

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or “Complete”, it will remain in this state. A number of factors,
including erasing of diagnostic trouble codes (DTCs) with a scan tool
or a disconnected battery, can result in Readiness Monitors being set
to “Not Ready”. Since the three continuous monitors are constantly
evaluating, they will be reported as “Ready” all of the time. If testing
of a particular supported non-continuous monitor has not been
completed, the monitor status will be reported as “Not Complete” or
“Not Ready.”
In order for the OBD monitor system to become ready, the vehicle
should be driven under a variety of normal operating conditions.
These operating conditions may include a mix of highway driving and
stop and go, city type driving, and at least one overnight-off period.
For specific information on getting your vehicle’s OBD monitor
system ready, please consult your vehicle owner’s manual.
2.6 OBD II Definitions
Power-train Control Module (PCM) -- OBD II terminology for the
on-board computer that controls engine and drive train.
Malfunction Indicator Light (MIL) -- Malfunction Indicator Light
(Service Engine Soon, Check Engine) is a term used for the light on
the instrument panel. It is to alert the driver and/or the repair
technician that there is a problem with one or more of vehicle's
systems and may cause emissions to exceed federal standards. If the
MIL illuminates with a steady light, it indicates that a problem has
been detected and the vehicle should be serviced as soon as possible.
Under certain conditions, the dashboard light will blink or flash. This
indicates a severe problem and flashing is intended to discourage
vehicle operation. The vehicle onboard diagnostic system can not turn
the MIL off until necessary repairs are completed or the condition no
longer exists.
DTC -- Diagnostic Trouble Codes (DTC) that identify which section
of the emission control system has malfunctioned.
Enabling Criteria -- Also termed Enabling Conditions. They are the
vehicle-specific events or conditions that must occur within the
engine before the various monitors will set, or run. Some monitors

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require the vehicle to follow a prescribed “drive cycle” routine as part
of the enabling criteria. Drive cycles vary among vehicles and for
each monitor in any particular vehicle.
OBD II Drive Cycle -- A specific mode of vehicle operation that
provides conditions required to set all the readiness monitors
applicable to the vehicle to the “ready” condition. The purpose of
completing an OBD II drive cycle is to force the vehicle to run its
onboard diagnostics. Some form of a drive cycle needs to be
performed after DTCs have been erased from the PCM’s memory or
after the battery has been disconnected. Running through a vehicle’s
complete drive cycle will “set” the readiness monitors so that future
faults can be detected.Drive cycles vary depending on the vehicle and
the monitor that needs to be reset. For vehicle specific drive cycle,
consult the vehicle’s Owner’s Manual.
Freeze Frame Data -- When an emissions related fault occurs, the
OBD II system not only sets a code but also records a snapshot of the
vehicle operating parameters to help in identifying the problem. This
set of values is referred to as Freeze Frame Data and may include
important engine parameters such as engine RPM, vehicle speed, air
flow, engine load, fuel pressure, fuel trim value, engine coolant
temperature, ignition timing advance, or closed loop status.
2.7 OBD II Modes of Operation
Here is a basic introduction to the OBD II communication protocol.
Mode byte: The first byte in the stream is the mode number. There
are 10 modes for diagnostic requests. The first byte in the response
data bytes is this same number plus 64. For example, a mode 1
request would have the first data byte = 1, and the response would
have the first data byte = 65. Here is a brief description of the modes:
Mode $01 –Identifies the Powertrain information and shows
current data available to the scan tool. This data includes: DTC set,
status of on-board tests, and vehicle data such as engine RPM,
temperatures, ignition advance, speed, air flow rates, and closed loop
status for fuel system.

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Mode $02 –Displays Freeze Frame data. Same data as in mode 1,
but it was captured and stored when a malfunction occurred and a
DTC was set. Some of the PIDs for mode one are not implemented in
this mode.
Mode $03 –Displays the type of powertrain or emission related
DTCs stored by a 5 digit code identifying the faults. There may be
more than one response message if there are more trouble codes than
will fit in the data bytes of the response message, or if there are more
than one ECU computer responding.
Mode $04 –Used to clear DTCs and Freeze Frame data. This
clears all diagnostic trouble codes that may be set including freeze
frame data and readiness monitors.
Mode $05 –Displays oxygen sensor test results. This mode
displays the oxygen sensor monitor screen and the test results
gathered about the oxygen sensor.
There are ten numbers available for diagnostics:
1. $01 Rich-to-Lean O2 sensor threshold voltage.
2. $02 Lean-to-Rich O2 sensor threshold voltage.
3. $03 Low sensor voltage threshold for switch time
measurement.
4. $04 High sensor voltage threshold for switch time
measurement.
5. $05 Rich-to-Lean switch time in ms.
6. $06 Lean-to-Rich switch time in ms.
7. $07 Minimum voltage for test.
8. $08 Maximum voltage for test.
9. $09 Time between voltage transitions in ms.
Mode $06 –Non-continuously Monitored Systems test results.
There are typically a minimum value, a maximum value, and a
current value for each non-continuous monitor. This data is optional,
and it is defined b a given vehicle maker if it’s used.
Mode $07 –A request for DTCs (pending) from Continuously
Monitored Systems after a single driving cycle has been

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performed to determine if repair has fixed a problem. This used
by service technicians to verify repair was performed properly and
after clearing diagnostic trouble codes.
Mode $08 –This special Control Mode requests control of the
on-board system, test, or component bi-directionally (where
applicable). This mode is manufacturer specific.
Mode $09 –Reports vehicle information. This information
includes vehicle VIN number and calibration information stored in
the vehicle ECUs.
Mode $0A –Requests Emission-Related Diagnostic Trouble
Codes with Permanent Status. This mode is required for all
emissions-related DTCs. The presence of permanent DTCs at an
inspection without the MIL illuminated is an indication that a proper
repair was not verified by the on-board monitoring system.

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3. Using the Scan Tool
3.1 Tool Description
1) OBD II CONNECTOR –Connects the scan tool to the
vehicle’s Data Link Connector (DLC).
2) LCD DISPLAY –Indicates test results.
3) GREEN LED –Indicates that engine systems are running
normally (The number of monitors on the vehicle which are
active and performing their diagnostic testing is in the allowed
limit, and no DTCs are present).

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4) 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.
5) 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
DTCs are present. DTCs are shown on the Scan Tool’s display.
In this case, the MIL lamp on the vehicle’s instrument panel
will light steady on.
6) ONE-CLICK I/M READINESS KEY –Quick-checks
State Emissions readiness and drive cycle verification.
7) ESC BUTTON –Cancels a selection (or action) from a
menu or returns to the previous screen.
8) LEFT SCROLL BUTTON –When look up DTC
definitions, moves to previous character and views additional
information on previous screens if DTC definition covers more
than one screen; deselect all marked PID data when viewing or
recording customized live data list; views previous frames of
recorded data when playing back live data. It is also used to
update DTC library when pressed.
9) POWER BUTTON –Press and hold for 2 seconds to turn
the scan tool on and off. Press and then release to view ? help
information.
10) UP SCROLL BUTTON –Moves up through menu and
submenu items in menu mode. When more than one screen of
data is retrieved, moves up through the current screen to the
previous screens for additional data.
11) OK BUTTON –Confirms a selection (or action) from a
menu.
12) RIGHT SCROLL BUTTON –When look up DTC
definitions, moves to next character and view additional
information on next screens if DTC definition covers more than

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one screen; selects/deselects PID data when viewing or
recording customized live data list, and views next frames of
data when playing back live data.
13) DOWN SCROLL BUTTON –Moves down through
menu and submenu items in menu mode. When more than one
screen of data is retrieved, moves down through the current
screen to next screens for additional data.
14) VΩTERMINAL –Assists voltage and/or resistance test as a
lead.
15) COM TERMINAL –Assists test as a ground lead.
16) mA TERMINAL –Assists current (0～200mA) test as a lead.
17) A TERMINAL –Assists current (0～20A) test as a lead.
18) USB CONNECTOR –Connects the scan tool to the PC for
printing and upgrading.
19) EXTERNAL DC POWER PORT –Connects the 5 volt power
adapter to power the tool when disconnected from the vehicle or
charge the battery.
20) STAND –Flips out for supporting the scan tool.
3.2 Specifications
1) Display: TFT color display (320 x 240 dpi)
2) Operating Temperature: 0 to 60°C (32 to 140 F°)
3) Storage Temperature: -20 to 70°C (-4to 158 F°)
4) Dimensions:
Length Width Height
175 mm (6.91”) 96.6 mm (3.80”) 37 mm (1.46”)
5) Weight: 0.3kg (without wire) 0.68kg (with wire)

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3.3 Accessories Included
1) User’s Manual -- Instructions on tool operations.
2) CD -- Includes user’s manual, MaxiLink update software, and
etc.
3) OBD2 Cable -- Provides power to tool and communicates
between tool and vehicle.
4) USB Cable -- Used to upgrade the scan tool, and to print
retrieved data.
5) 3.7V Li-ion Battery -- Provides power when disconnected with
vehicle.
6) Probes -- Contacts the circuit or component to be tested.
AutoLinkAL539 Only:
7) Protective Nylon Case –Contains the main unit and cables
while not in use.
AutoLinkAL539B Only:
8) Battery Test Cable -- Used to contact the terminals of vehicle
battery.
9) Carry Case -- A nyloncase to store the scan tool when not in use.
3.4 Navigation Characters
Characters used to help navigate the scan tool are:
1) “$”-- Identifies the control module number from which data is
retrieved. Indicates the Test ID in On-Board Mon. Test.
2) “G”-- Indicates graphic viewing is available.
3.5 Keyboard
No solvents such as alcohol are allowed to clean the keypad or display.
Use a mild nonabrasive detergent and a soft cotton cloth. Do not soak
the keypad as the keypad is not waterproof.

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3.6 Power and Charge
Power on
Before using the scan tool, you must provide power to it. There are
five methods for providing power to the scan tool.
Cable connection to vehicle.
AC/DC external power adapter.
Li-ion battery.
USB port.
Battery test cable.
During vehicle testing, power for the scan tool is usually provided
through the vehicle cable connection. The detailed instructions show
as below:
1) Connect the OBD II Cable to scan tool.
2) Find DLC on vehicle.
A plastic DLC cover may be found for some vehicles and you
need to remove it before plugging the OBD2 cable.
3) Plug OBD II cable to the vehicle’s DLC.
When the scan tool is not connected to a vehicle, it can be powered
in the other three ways.
Auto power-off
Solely powered up by Li-ion battery, the tool will automatically turn
off after 15 minutes of inactivity.
Li-ion battery charging
You can charge your Li-ion battery by connecting it to an external
power adapter, by connecting it to the vehicle’s DLC or by
connecting it to a USB port on your computer. The tool displays a
battery icon in the upper-right corner of the screen to show
approximately how much charge is left. (Note: This battery icon only
appears when you are choosing the "Circuit test" function, “BAT
test”or "Start test" function.)

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Using a Power Adapter
If you're using an external power adapter, connect the tool to the
adapter. Then plug the adapter into a working electrical socket.
Using your computer
If you want to charge the tool using your computer, make sure
that your computer is turned on, it isn't sleeping (refer to the
computer's manual to find out how to turn sleep off), and that the
USB you connect the tool to provides power. Also, make sure to
use the high-powered USB ports which are typically found on the
computer itself ----- not on your keyboard, which is low-powered.
NOTE: If using a portable computer, make sure it is plugged into
power and that the lid or display is open because if the lid is
closed the computer may go into either standby, sleep, or
hibernation mode and the tool will not charge.
Using vehicle DLC
If you want to charge the tool with vehicle DLC, the detailed
instructions are described as above (refer to the Power on
instructions).
Using vehicle battery
If you want to charge the tool with vehicle battery, use the battery
test cable to connect the tool to the battery.
Once connected, the Li-ion battery will be fully charged in about 2.5
hours. You can disconnect and use the tool before the battery is fully
charged. You don't have to wait until the battery is completely empty
before charging it again.
The battery stops charging when it's full, so you don't have to worry
if you leave it plugged in overnight (leaving the tool connected to an
electrical source all the time doesn't continuously charge it). Once

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the battery is charged, disconnect the tool. If you're using your
computer to charge it, make sure that you disconnect your tool
correctly when it's finished charging.
3.7 DTC Lookup
The DTC Lookup function is used to search for definitions of DTCs
stored in the DTC library and for code breaker information.
1) From Main Screen (Figure 3.1), use the UP/DOWN scroll button
and LEFT/RIGHT scroll button to select DTC Lookup and
press the OK button.
Figure 3.1
2) From DTC Lookup screen, use the LEFT/RIGHT button to
move to the desired character, use the UP/DOWN button to
change selected digit/character and press the OK button to
confirm. (Figure 3.2)
Figure 3.2
DTC Lookup
P 0 0 0 1
Left
Right
Change digit
OK
Confirm
ESC
Exit
［］［ ］- Change Digit
［ENTER］- Confirm
［ESC］- Exit

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3) View the DTC definition on screen. When DTC definition covers
more than one screen, use the LEFT/RIGHT button or
UP/DOWN button to view additional information on
previous/next screens.
For manufacturer specific codes, you need to select a vehicle
make on an additional screen to look for DTC definitions.
If definition could not be found (SAE or Manufacturer
Specific), the scan tool displays “Please refer to vehicle
service manual!”
For code breaker information, you need to press the “?” Help
button.
In the Code Breaker screen, there are three options to assist user to
understand DTC more: System Description and Quick Check to
read detailed description of DTCs, General Notes to view helpful
repair information of DTCs.
4) To view previous or next DTC in the built-in DTC library, use the
LEFT/RIGHT button.
5) To enter another DTC, press the ESC button to return to previous
screen.
6) To exit to Main Screen, press the ESC button.
3.8 System Setup
The scan tool allows you to make the following adjustments and
settings:
1) Language: Selects the desired language.
2) Configure Monitors: Sets the monitors you want to test.
3) Unit of measure: Sets the unit of measure to English or Metric.
4) Key Beep Set: Turns on/off beep.
5) Status Beep Set: Turns on/off the I/M Readiness Status beep.
6) Tool Self-test: Checks if the LCD display, LED lamps and
keyboard are working normally.

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7) Tool Information: Views the important information of the tool.
8) Update Mode: Accesses the Update Mode.
Settings of the unit will remain until change to the existing
settings is made.
To enter the Setup menu
From the Main Screen: Use the UP/DOWN scroll button and
LEFT/RIGHT scroll button to select Setup, andpress the OK button.
Follow the instructions to make adjustments and settings as described
in the above setup options. (Figure 3.3)
Figure 3.3
Language Setup
English is the default language.
1) From System Setup screen, use the UP/DOWN scroll button to
select Language, and press the OK button.
2) Use the UP/DOWN scroll button to select the desired language
and press the OK button to save your selection and return to
previous screen. (Figure 3.4)
System Setup 1/8
Language
Configure Monitors
Unit of Measure ?
Key Beep Set
Status Beep Set
Tool Self-test
Tool Information