Honda Acura NSX 1991 Service Manual page 281

(From page 1 1 - 104)
Turn the ignition switch off.
Connect the ECU test harness
between the ECU and connector.
Disconnect "A" connector from
the engine wire harness only, not
the ECU (page 1 l-21 ).
Check for continuity between
terminal @ and A7 ter-
minal.
Does continuity exist?
I
Y E S
t h e vyltage b e t w e e n
A25 (+) terminal and A23 (-4 ter-
Is there battery voltage?
YES
Measure the voltage between A7
minal.
Is there 1 V or less?
(for 2 seconds)
Replace main relay.
Repair open in GRNIBLK wire
N O
between ECU (A71 and Main
Relay.
battery voltage?
I
0000000000000 00000000 000000 00000000000
Replace main relay.
1 v or less?
A7 I+)
I
Substitute a known-good ECU
N O
a n d r e c h e c k . I f p r e s c r i b e d
voltage is now available, replace
the original ECU.
n
A 2 3 l - l
II-105