LAUNCH
X-431 GDS User’s Manual
61
9.2 Ignition
The ignition system is the system which has greatest impact on the
performances of gasoline engine, as the statistical data shows that nearly half
of the failures are caused by poor work of electrical system. And the
performance tests of engine often start from the ignition system. Nowadays
ignition system includes distributor and distributorless. Distributorless includes
independent ignition and simultaneous ignition.
1. Distributor ignition system: conventionally includes contact breaker
(commonly known as the platinum) contact-controlled ignition system and
magnet, infrared or hall components breakless ignition system.
2. Direct ignition system: crankshaft sensor send out the ignition timing signal
and cylinder identification signal for the specified cylinder send out the
specified signal in specified time, each cylinder has its independent ignition
coil.
3. Simultaneous ignition system: two cylinders share one ignition coil, when
two cylinder pistons reach top dead center at the same time (one is
compression, the other is the exhaust), two spark plugs will be ignited at the
same time, at this time, the ignition for the former cylinder with
high-pressure low temperature gas mixture, the ignition is valid, while for
the latter one with low-pressure high temperature exhaust gas, the ignition
is invalid.
X-431 GDS can test and analyze the primary/secondary signal coming from
various engine ignition systems.
For detailed operations and specifications, refer to X431 GDS Scopebox
user’s manual.
9.3 Sensor
Vehicle sensors are the signal input devices for electrical control systems,
which can transform all kinds of running parameters, such as vehicle speed,
coolant temperature, engine RPM, air flow, throttle opening, etc., into the
electronic signal for the vehicle computer who can optimize the engine running
status per the above-mentioned parameters to keep the engine working in a
prime status. As the sensors can be separated into many types, when you
troubleshoot a related-sensor fault, you shall focus not only on the sensor itself,
