FI SYSTEM DIAGNOSIS 4-5 • When disconnecting and connecting the ECM, make sure to turn OFF the ignition switch 1, or electronic parts may get damaged. • Battery connection in reverse polarity is strictly prohibited. INCORRECT Such a wrong connection will damage the components of the FI system instantly when reverse power is applied. • Removing any battery terminal of a running engine is strictly E prohibited. The moment such removal is made, damaging counter elec- L tromotive force will be applied to the ECM which may result in serious damage. P SAM • Before measuring voltage at each terminal, check to make sure that battery voltage is 11 V or higher. Terminal voltage check with a low voltage battery will lead to erroneous diagno- sis. • Never connect any tester (voltmeter, ohmmeter, or whatever) to the ECM when its coupler is disconnected. Otherwise, damage to ECM may result. • Never connect an ohmmeter to the ECM with its coupler con- nected. 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.