Code 1 and code 43 OBD1

TULEL1

MEMBER
1990 HONDA ACCORD
AUTOMATIC
146,000 MILES

My 90 honda accord is showing code 43 (obd1) ( fuel supply system) so how should I fix this issue. Its also showing code 1 which is about the o2 sensor. The check engine light comes on during occasionaly while driving and dissappears when I shut off the engine.

1 Reply

HMAC300

MECHANIC
48,601 POSTS

CODE� 43 � FUEL� SUPPLY� SYSTEM

1. Turn� ignition� off.� Remove� BACK UP� fuse� in� the� under hood� relay� box� for� 10� seconds� to� reset� ECU.� Start� engine� and� warm� to� normal� operating� temperature� (cooling� fan� comes� on).� Raise� engine� speed� to� 3000
RPM� and� hold� for� 2� minutes.� Verify� if� CHECK� ENGINE� light� is� on� and� if� LED� is� flashing Code� 43.1f� LED� is� flashing Code� 43, � go� to� next� step.� If� LED� is� not� flashing Code� 43, � problem� is� intermittent.� Check
connections� at� O2� sensor, � related� circuits� and� at� ECU.
2. Turn� ignition� off.� Connect� ECU� Test� Harness� between� ECU� and� connector.� Wait� at� least� 2� minutes� with� ignition� off.� Turn� ignition� on.� Measure� voltage� between� terminals� D14� (positive)� and� A26� (negative)� as� soon
as� ignition� is� turned� on.� If� less� than�.1� volt� is� present� when� ignition� is� first� turned� on, � got� to� step� 4).� If� more� than�.1� volt� was� present, � go� to� next� step.
3. Disconnect� 4 wire� connector� from� O2� sensor.� Measure� voltage� at� O2� sensor� connector� between� terminal� "C"� (negative)� and� "D"� (positive).� If� voltage� is� more� than�.1� volt, � replace� O2� sensor.� If� voltage� was� less
than�.1� volt, � repair� open� in� White� wire� between� ECU� terminal� D14� and� O2� sensor.
4. Disconnect� 4 wire� connector� from� O2� sensor.� Measure� voltage� between� terminals� D14� (positive)� and� A26� (negative).� If� voltage� is� more� than�.1� volt, � replace� O2� sensor.� If� voltage� was� less� than�.1� volt, � disconnect
test� connector� "D"� from� main� wire� harness.
Note this can also set you r code 1