Pontiac Fiero 1988 Service Manual page 482

DRIVEABILITY AND EMISSIONS - FUEL INJECTION (TBI) 6E2-A-27
CODE 13
OXYGEN SENSOR CIRCUIT
(OPEN CIRCUIT)
2.5L "P" SERIES (TBI)
©
ENGINE AT NORMAL OPERATING TEMPERATURE (ABOVE 80°C ).
• RUN ENGINE ABOVE 1200 RPM FOR TWO MINUTES.
DOES "SCAN" INDICATE "CLOSED LOOP"?
©
NO
r
• DISCONNECT 0
2
SENSOR.
• JUMPER HARNESS CKT 412 TO GROUND.
"SCAN" SHOULD DISPLAY 0
2
VOLTAGE BELOW .2
VOLTS (200 mV) WITH ENGINE RUNNING.
DOES IT?
YES
x _
CODE 13 IS INTERMITTENT. IF NO
ADDITIONAL CODES WERE STORED,
REFER TO "DIAGNOSTIC AIDS" ON
FACING PAGE..
©
NO
I
• IGNITION "ON", ENGINE "OFF".
• CHECK VOLTAGE OF CKT 412 AT 0
2
SENSOR
HARNESS CONNECTOR USING A DVM.
IT SHOULD BE .3.6 VOLTS (300 - 600 mV).
1
YES
X _
FAULTY 0
2
SENSOR
CONNECTION OR SENSOR.
.3-.6 VOLTS
(300-600 mV)
OVER .6 VOLT
(600 mV)
LESS THAN .3
VOLT (300 mV)
FAULTY ECM
OPEN CKT 413,
FAULTY CONNECTION
OR FAULTY ECM.
OPEN CKT 412, FAULTY
ECM CONNECTION OR ECM.
CLEAR CODES AND CONFIRM "CLOSED LOOP" OPERATION AND NO "SERVICE ENGINE SOON" LIGHT.
2-20-87
• 7S3054-6E