Federal

TROUBLESHOOTING PROCEDURES





CIRCUIT DIAGRAM





INSPECTION USING SCAN TOOL











HARNESS INSPECTION PROCEDURE

TROUBLESHOOTING HINTS
Hint 1:Poor cleaning of exhaust gas will result if the heated oxygen sensor fails.
Hint 2:If the heated oxygen sensor checked good but the sensor output voltage is out of specification, troubles of parts related to air-fuel ratio control system are suspected.
1. Faulty injector
2. Air leaking into the intake manifold through gasket gap, etc.
3. Faulty volume air flow sensor, intake air temperature sensor, barometric pressure sensor, engine coolant temperature sensor

SENSOR INSPECTION
(1) Disconnect the heated oxygen sensor connector.
(2) Check that there is continuity [approx. 20 Ohms at 20°C (68°F)] across terminals (3) and (4) of the heated oxygen sensor connector.
(3) If there is no continuity, replace the heated oxygen sensor.





(4) Warm up the engine until the engine coolant temperature becomes 80°C (176°F) or higher.
(5) Using jumper wires, connect terminals (3) and (4) of the heated oxygen sensor connector to battery (+) and (-) terminals respectively.
Caution: Ensure that the jumper wires are connected correctly, as wrong connections result in a broken heated oxygen sensor.
(6) Connect a digital voltmeter across terminals (1) and (2).





(7) Racing the engine repeatedly and measure the output voltage of the heated oxygen sensor.