LAUNCH X-431TOP User
’
s Manual
25
Precautions on Checking Vehicle
Sensor
l
Hold the connector when plug or unplug it.
Do not pull the cable for unplugging.
l
At first check the fuse, fusible line and
connection port. Then check others after
eliminating these faults.
l
When measuring the voltage, the ignition
switch should be turn on and the battery
voltage should not be less than 11V.
l
When measuring the voltage, please shake
the lead lightly in the vertical and level
direction for much veracity.
l
When checking if there is a fault of the line
open-circuit or not, at first disconnect the
CEU and the relevant sensor, then measure
the resistance among the ports of sensor in
order to make sure there is open-circuit and
contact fault or not.
l
When checking if there is a short circuit
fault or not, please disconnect the CEU and
the relevant sensor, then measure the
resistance value of the ports between the
connected port and the vehicle body. When
the resistance value is more than 1M
Ω
,
there is no fault.
l
Before disassembling the engine electrical
control system cable, cut off the power
supply, that is, the ignition switch is turned
off.
l
Pay attention to choose the correct GND
ports of connectors.
l
Contact the test probe and the two ports/ the
two leads to be measured when measuring
the voltage between the two ports or the two
leads.
l
Contact the test probe to the ports/ the cable
to be measured, and the negative connector
to the ground when measuring voltage of
one port/ one cable.
l
Checking the continuity of the ports, contact
and lead is checking the ports, contact and
lead electrify or not. The measure way for
voltage value can be used here.
l
Check the faults in the ports of the CEU to
sensors, relays, etc.
l
There are two test probes in the testing line.
The black one is the signal public port( signal
GND); the red one is the input port for
voltage, resistance, frequency test and
output port for simulation voltage, simulation
frequency and
λ
oxygen sensor. Please
choose the correct probes to match the
different ports.
Vehicle autobase
This function provides the system circuit diagram
of normal model. Click
“
Vehicle autobase
”
on the
main menu (See fig. 3-1) to enter the fig. 3-34).
Fig.3-34
Click
“
+
”
on the left index to expand the index.
Select the circuit diagram to view. The circuit
diagram of the system will be displayed in the
right section. (See fig. 3-35)
Fig. 3-35
index
Select language
drop down menu
button
Circuit diagram
display section
Click
“
index
”
to
close the index and
re-click to resume.
Alter display font
Print circuit diagram