Honda Civic Service Manual page 479

t
Alternator (ALT) FR Signal ('99 - 00 Models except Dl6Y5 engine with
M/T)
This signals the ECM/PCM when the Alternator {ALT) is charging
ECM/PCM CONNECTORS
Wire side of female terminals
ECM/PCM CONNECTOR C (31P}
l t
lP
ALT CONNECTORS IClO4I
JUMPER
JUMpER WlnE
WIRE
Wire side of female termlnals
ECM/PCM CONNECTOR C (31PI
3P*
N O
Check lor an op€n in the wire (ALT
F line,:
1. Turn the agnition switch OFF
2. Disconnect the negative bat-
tery cable {rom the battery.
3. Disconnect the ECM/PCM con'
nector C (31P).
4. Disconnect the 4P (3P)* con'
nector from the ALT.
5. Connect the ALT 4P (3P)* con-
nector terminal No 4 (No. 1)*
to bodY ground with a iumper
6. Check lor continuity between
b o d y g r o u n d a n d E C M / P C M
connector terminal C5
--?--
1 l 2 l
|#
i 3 l . l
otriJ
rwxrr (V)
neor Y
lnsoeclion oI ALT FB Signal.
Check {or a short in the wire {ALT
F line):
1. Disconnect the 4P (3P)+ con
nector from the ALT
2. Turn the ignition switch ON (ll)
3. Measurc voltage between EcM/
PCM connector terminals C5
and 820.
Check tor a short in the wirc (ALt
F line):
1. Turn the ignition switch OFF
2. Disconnect the negative bat_
tery cable from the baRery'
3. Disconnect the ECM/PCM con'
nector C (31P).
4. Check for continuity between
b o d y g r o u n d a n d E C M / P C M
connector terminal C5
ls there aPProx. 5 V?
Check the operation otthe ALT:
1. Turn the ignition switch OFF.
2 - R e c o n n e c t t h e A L T 4 P ( 3 P ) *
connector to the ALT
3 . S t a r t t h e e n g i n e . H o l d t h e
engine at 3,000 rpm wrth no
load {in Park or neutrali until
t h e r a d i a t o r f a n c o m e s o n ,
then let it idle.
4- Measure voltage between ECM/
PCM connector terminals C5
and 820.
Repair short in the wire between
the EcM/PCM {C5l and the ALT.
Substitute a known-good ECM/
PCM and rechock. lf P.esc.ibed
voltage is now availabl€, ieplace
tho original ECM/PCM
D o e s t h e v o l t a g e d e c r e a s e w h e n
h e a d l i g h t s a n d r e a r d e l o g g e r a r e
t u r n e d o n ?
ALT FF signal is OK.
Repair oPen wire betwoen t|lo
ECM,/PCM {C5) and the ALT.
ALT F (WHT/RED)
Wire side of temale terminals
* : C a n a d a m o d e l
Wire side of female termrnals