Honda Acura NSX 1991 Service Manual page 209

(From page 1 I-321
Check for continuity to body
ground on each terminal on the
02 sensor.
Does continuity exist?
terminal A and terminals C and D
Turn the ignition switch ON.
M e a s u r e v o l t a g e b e t w e e n
BLK/YEL (+) terminal and BLK f-)
t e r m i n a l .
Is there battery Voltage?
NO
M e a s u r e v o l t a g e b e t w e e n
BLK/YEL (+) terminal and body
ground.
Turn the ignition switch OFF.
I
(To page 1 I-34)
Y E S
Replace 02 sensor.
YES
t
Disconnect the "A" connector
from the ECU.
BLK/YEL (+I terminal and BLK f-1
Is
dash fuse box.
I
and recheck. If symptom/indica-
tion goes away, replace the
original ECU.
02 SENSOR
45 Nom
(4.5 kg-m, 33 lb-ft)
REAR
02 SENSOR
45 Nom
there battery voltage?
N O
Repair short in BLK or
w i r e b e t -
w e e n E C U (A10 or
and front 0 2
sensor.