Alternator Control System Test - Honda S2000 Service Manual

Charging System
3 .
Charging Circuit Troubleshooting (cont'd)
Alternator Control System Test
t
1 . Check for proper operation of the electrical load
detector (ELD) by checking that the maltunction
indicator lamp (MlL) (see page 1 1-3). lf a DTc is
present, diagnose and repair the cause betore
continuing with this test.
Disconnect the alternator 4P connector from the
alternator.
Start the engine, and turn the headlights (high
b e a m ) O N .
Measure voltage between the alternator 4P
connector terminal No. 2 and the positive terminal
of the battery.
c
1
2
3
,4
BATTERY
ALTERNATOR
4P CONNECTOR
{WHT/GRNI
Wire side of
lemale terminals
5 .
6 .
ls thete 1 V or less?
YES Go to step 8.
NO Go to step 5.
Turn the headlight and ignition switch OFF.
Disconnect engine control module {ECM)
c o n n e c t o r C { 3 1 P ) .
4-24
7. Check for continuity between the ECM connector C
t e r m i n a l N o . 2 a n d b o d y g r o u n d .
ECM CONNECTOR C {31PI
W i r e s i d e o f f e m a l e t e r m i n a l s
ls there continuity?
YES Repair short to ground in the wire between
the alternator and ECI\4.I
NO Check that the terminals are firmly seated at
the connectors. lf OK, substitute a known-good
P C M a n d r e c h e c k { s e e p a g e 1 1 - 4 ) . l f p r e s c r i b e d
voltage is now available, replace the original ECM
( s e e p a g e 1 ' l - 5 ) . I
8 , T u r n t h e h e a d l i g h t a n d i g n i t i o n s w i t c h O F F .
9. Disconnect ECM connector C (31P).
10. Check for continuity between the ECM connector C
t e r m i n a l N o . 2 a n d a l t e r n a t o r 4 P c o n n e c t o r t e r m i n a l
N o . 2 .
E C M C O N N E C T O R C { 3 1 P } 4 P C O N N E C T (
W i r e s i d e o f f e m a l e t e r m i n a l s
ls there continuity?
YES Repair the alternator (see page 4-29).1
NO Repair an open in the wire between the
a l t e r n a t o r a n d E C M . I