JAC HFC4DA1-2C, Руководство по обслуживанию

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ABS
ABS
ABS ABS Anti-lock
Anti-lock
Anti-lock Anti-lock Brake
Brake
Brake Brake System
System
System System
86
Diagnosis
Diagnosis Diagnosis
Diagnosis and
and and
and Testing
Testing Testing
Testing
Intermittent fault diagnosis table
Note: In case one of the following conditions occurs, there is intermittent fault.
Fault does not always occur;
It may probably occur again;
There is history DTC but no current DTC.
Inspection Operation
Preliminary inspection 1. Perform “preliminary inspection” at first;
2. Collect information relevant to the arising of intermittent fault from the customer, such
as:
1) Driving conditions (vehicle speed, brake, warning lamps and road condition) when the
fault occurs.
2) Does the fault occur during the application of electrical equipments added by service
shop?
3) Has the battery status been checked?
4) Have the wheel speed sensor harnesses and gear rings been checked?
Detection by diagnostic
instrument Detection procedures:
1. Operate the suspicious ABS component harnesses and connectors and observe the data
stream of measured circuit on the diagnostic instrument. If the reading of diagnostic
instrument fluctuates during this operation, please check circuits for loose connection.
2. Perform vehicle road test under occurrence of intermittent fault and ask an assistant to
observe the suspicious operating parameters on the diagnostic instrument.
3. Capture and store data by snapshot once fault occurs. The stored data can be displayed
at lower speed to facilitate diagnosis. Oscilloscope can also be applied for signal
detection.
4. Apply the “Component Test” function of diagnostic instrument to control the
suspicious ABS components to test their operation.
Warning lamps The following conditions may lead to intermittent illumination of warning lamps without
DTC set.
1. Warning indicator circuit is shorted to ground intermittently.
2. Ground points of ABS hydraulic governor with ECU or instruments become loose.
3. Battery voltage is a little lower or unstable under stationary state of vehicle.
Wheel speed sensor 1. Visually inspect wheel speed sensors and gear rings for looseness, damage, foreign
matters or improper installation. Please replace any damaged component, remove any
foreign matter or fix any loosened component accordingly.
2. Check the wheel speed sensor for proper wiring and ensure the harnesses of wheel
speed sensor are not interfered by mechanical components.
3. Monitor the data display of wheel speed sensor on diagnostic instrument with
assistance and at the same time perform road test to check if any wheel speed sensor in
abnormal speed range is displayed.
Additional testing 1. Check electrical equipments added by service shop such as mobile phones, anti-theft
warning devices, lamps, radio equipments, stereo amplifiers and so on for correct
installation.
2. Check if any electromagnetic interference (EMI) is caused by failed components (such
as relays or solenoid valves) with power on.
3. Power-on test for motors and solenoid valves.