Honda Acura NSX 1991 Service Manual page 297

(From page 1 l-l 20)
Raise engine speed to 5,000
rpm.
Check for vacuum at #3 vacuum
hose.
N O
Chamber volume control system
is OK.
(From page 1 I-1 20)
Is there battery voltage?
Y E S
Turn the ignition switch OFF.
Connect the ECU test harness
between the ECU and connector
(page 1 l-21).
Check for continuity of RED/BLU
wire between ECU (Al 4) and the
6P connector.
Does continuity exist?
Y E S
Substitute a known-good ECU
and
recheck. If symptom goes
away, replace the original ECU.
A l 4
Disconnect "A" connector from
ECU.
Check for continuity to ground
on the RED/BLU wire.
Is there continuity to grou
N O
Substitute a known-good ECU
and recheck. If symptom goes
away, replace the original ECU.
Repair open in BLK/
YEL wire between the
6P connector and No.
2 (15 A) fuse.
Repair open in RED/
B L U w i r e b e t w e e n
ECU (A14) and the 6P
connector.
Replace chamber vol-
ume control solenoid
valve.
Repair short to ground at
and the 6P connector.