Suzuki kq750 Service Manual page 10

Battery
• Battery connection in reverse polarity is strictly
prohibited. Such a wrong connection will damage the
components of the FI systems instantly when reverse
power is applied.
• Removing any battery terminal of a running engine is
strictly prohibited. The moment such removal is made,
damaging counter electromotive force will be applied
to the ECM which may result in serious damage.
• Before measuring voltage at each terminal, check to
make sure that battery voltage is 11 V or higher.
Terminal voltage check with a low battery voltage will
lead to erroneous diagnosis.
• Never connect any tester (voltmeter, ohmmeter, or
whatever) to the electronic unit when its coupler is
disconnected. Otherwise, damage to electronic unit
may result.
• Never connect an ohmmeter to the ECM with its
coupler connected. If attempted, damage to ECM or
sensors may result.
• Be sure to use a specified voltmeter/ohmmeter.
Otherwise, accurate measurements may not be
obtained and personal injury may result.
Electrical Circuit Inspection Procedure
While there are various methods for electrical circuit
inspection, described here is a general method to check
for open and short circuit using an ohmmeter and a
voltmeter.
I718H1000004-01
Open circuit check
Possible causes for the open circuit are as follows. As
the cause can exist in the connector/coupler or terminal,
they need to be checked carefully.
• Loose connection of connector/coupler
• Poor contact of terminal (due to dirt, corrosion or rust,
poor contact tension, entry of foreign object etc.)
• Wire harness being open.
• Poor terminal-to-wire connection.
When checking system circuits including an electronic
control unit such as ECM, etc., it is important to perform
careful check, starting with items which are easier to
check.
1) Disconnect the negative (–) cable from the battery.
2) Check each connector/coupler at both ends of the
I310G1000011-01
circuit being checked for loose connection. Also
check for condition of the coupler lock if equipped.
1. Sensor
I310G1000012-02
"A"
"A"
1
"A": Check for loose connection
Precautions: 00-4
ECM
I718H1000005-02