Transcript Anti-Lock Braking System Diagnostics Motor Vehicle Level 3

Motor Vehicle Level 3
Resource 6
Anti-Lock Braking System Diagnostics
Motor Vehicle Level 3
Resource 6
Aims
Recognise the diagnostics procedures within ABS systems
Anti-Lock Braking System Diagnostics
Motor Vehicle Level 3
Resource 6
Anti-Lock Braking System Diagnostics
Objectivies
By the end of the session you will be able to:
1) Recognise the tools used to diagnose faults within ABS systems
2) List a diagnostic procedure for diagnosing a fault within ABS systems
3) Recognise different types of diagnostic systems.
Motor Vehicle Level 3
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Anti-Lock Braking System Diagnostics
On board and Off board diagnostic
•ON board diagnostic refers to a self diagnostic procedure that the vehicle performs during
start up
•OFF board diagnostic refers to diagnostic done by a technician via a scan tool.
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Diagnostic tools.
Diagnostic tools could include the following:•Multi meter
•Hand scan tool
•Sun diagnostic Machine/computer
•based diagnostic system
Anti-Lock Braking System Diagnostics
Motor Vehicle Level 3
Resource 6
Anti-Lock Braking System Diagnostics
Diagnostic tools
Multi-meter
•A multi meter is used to read voltages (AC and DC), current and resistance through a
circuit.
•It can also be used to measure continuity throughout a circuit.
•The scale can be altered to suit the amount of voltage etc that you are measuring.
Motor Vehicle Level 3
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Anti-Lock Braking System Diagnostics
Diagnostic Tools
Hand Scan tools
•Is plugged into the vehicle via the OBDII port.
•Shows trouble codes in order to aid diagnostic of a system fault.
•This is the most common method
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Diagnostic Tools
Sun diagnostic machine/computer based diagnostic
software
•Similar to a scan tool is used to show diagnostic
codes, however waveform patters can also be
shown.
•Software can be uploaded to the technicians laptop
Anti-Lock Braking System Diagnostics
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Anti-Lock Braking System Diagnostics
Diagnostic Function
•When a fault occurs within a vehicle’s system a MIL (Malfunction Indicator Light) lights up to
display to the driver that there is a fault.
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Anti-Lock Braking System Diagnostics
Diagnostic Function
•The vehicle will then store a code within the vehicles ECU so that a technician can access it
via a scan tool (hand scanner or Sun diagnostic machine)
•The technician can now begin to solve the problem(s) within that system
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Anti-Lock Braking System Diagnostics
How to access the trouble codes
There are various methods that the technician can use to access the code. This could
include
•OBD II port
•Blink Codes
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Anti-Lock Braking System Diagnostics
How to access the trouble codes
Blink Codes
•Sometimes known as flash codes
•Once the scan tool has been connected a LED will light for a considerable while.
•After which the LED will begin to flash a code (similar to Morse code) which the technician
records.
•The technician can then detect where the problem on the system by looking up the code
within the specification documentation.
•The LED will illuminate for a long time to show that the code has finished being transmitted.
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How to access the trouble codes
OBD port
•The most common way of accessing the
fault code is via the diagnostic port.
•This is normally located within the
passenger foot well
•This is the location within vehicles
after 2000 (EOBD),
•For vehicles before this year-see
manufacture spec.
Anti-Lock Braking System Diagnostics
Motor Vehicle Level 3
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Anti-Lock Braking System Diagnostics
How to access the trouble codes
•Once the scan tool has been connected to the vehicle, the technician can scan the ECU for
a trouble code.
•This is shown on the tool itself
•The technician can now refer to the specification documentation in order to resolve the
systems fault.
•Some EOBD scan tools can also show live data and waveforms
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Anti-Lock Braking System Diagnostics
How to access the trouble codes
•Scan tools come with a set of cartridges.
•Each cartridge has diagnostic information regarding each manufacture.
•These are updated as vehicles change or new models are released
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Trouble codes
•OBD (before 2000) has three to five
digit codes
•EOBD (after 2000) have a
standardised code.
•After the fault has been repaired it is
important that the code is then cleared
via the scan tool.
Anti-Lock Braking System Diagnostics
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Anti-Lock Braking System Diagnostics
How to access the trouble codes
Activity
•In groups of three discuss the advantages and disadvantages of each system.
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Anti-Lock Braking System Diagnostics
Typical diagnostic procedure
A customer has come to your workshop stating that the ABS light is on.
•Individually write a diagnostic procedure for the sequence you would conduct in order
to solve the problem.
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Anti-Lock Braking System Diagnostics
Typical diagnostic procedure
•Confirm with the customer (customer service) what the fault is and symptoms. (if
possible road test with the customer)
•Ensure the correct cartridge/key is in the scan tool
•Connect to the OBD port
•Switch on Ignition
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Typical diagnostic procedure
•Enter the vehicles details (VIN number)
•Retrieve code from ECU (refer to tool manual)
•Refer to manual with regards to the vehicle code
•Repair the fault.
•Ensure all codes are cleared from ECU
•Remove scan tool
Anti-Lock Braking System Diagnostics
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Typical diagnostic procedure
•Road test the vehicle to ensure that the fault has cleared
Anti-Lock Braking System Diagnostics
Motor Vehicle Level 3
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Anti-Lock Braking System Diagnostics
Summary
Have we:•1) Recognised the tools used to diagnose faults within ABS systems
•2) Listed the steps within a diagnostic procedure for diagnosing a fault within ABS
systems
•3) Recognised different types of diagnostic systems.