Signal - Honda Acura NSX 1991 Service Manual

Idle Control System
-Troubleshooting Flowchart
This signals the PGM-FI ECU when the alternator is charging.
Inspection of Alternator

signal.

Connect the ECU test harness
between the ECU and connector.
Disconnect "D" connector from
the engine wire harness only, not
the ECU (page 11-21).
Turn the ignition switch ON.
Measure voltage between D9
minal.
Is there approx. 5 V7
Y E S
Turn the ignition switch OFF.
Reconnect "D" connector to the
engine wire harness.
Warm up engine,@ normal oper-
ating temperature" (cooling fan
comes on).
Measure voltage between D9
a n d A 2 6 (4 ter-
Does the voltage decrease when
headlights and rear defogger are
turned on ?
Y E S
Alternator FR signal is OK.
(To page 1 l-75)
Alternator FR Signal
FR
S u b s t i t u t e
E C U a n d r e c h e c k . I f p r e -
NO
scribed voltage is now avail-
a b l e , r e p l a c e t h e o r i g i n a l
ECU.
A26 (-1
a k n o w n - g o o d
Voltage 7
A26 l-1
Stop the engine.
I