Maintenance Manual for Chery·Windcloud Marelli EFI System
6. Diagnostic Steps for Various Engine Failures
Preliminary inspection shall be carried out before proceeding with diagnostic steps for any
engine failure:
(1). Make sure ECU and fault indicating lamp are working normally.
(2). Check with scanner to make sure that there is no failure information recorded.
(3). Check warming-up idling data of ECU with scanner to make sure that each value is
within normal range.
(4). Confirm the existence of failure complained by vehicle owner and locate the specific
failure.
Then appearance inspection:
Check ground point of wire harness to see if it is clean and firm.
Check vacuum pipe to see if it is properly connected, or if it is broken or twisted.
Check pipelines to see if blockage occurs.
Check intake pipe to see if it is squashed or damaged.
Check the sealing surface between throttle body and intake manifold to see if it is in good
condition.
Check high voltage wire of ignition system to see if it is properly laid out with no breakage
or aging.
Check connections to see if they are properly made; check contacts to see if they are loosed
or poorly connected.
Warning: Special attention must be paid to ground points (accumulator, ECU and
gauges, etc.) on motor vehicles. If any of these points is imporperly grounded, some
troublesome problems will occur. Sometimes these points are missed in inspection
because they look like steady without looseness; however some ground points may be
covered by a layer of paint coated during painting of the motor vehicles, which hinders
the connection of ground wires. Therefore, in case of troublesome problems, first pull
out ground wires, grind ground points and then reconnect wires.
35
To Next Page
Loading...
