Maintenance Manual for J2 Sedan
Electronic Control System
192
Front (upstream) oxygen sensor is installed on the
exhaust manifold before the three-way catalyst
converter and the rear (downstream) oxygen sensor is
installed behind the three-way catalytic converter.
3.
Pin 39: Downstream oxygen sensor grounding
Pin 29: Downstream oxygen sensor signal
Pin 4: Downstream oxygen sensor heating control
Pin 39: Upstream oxygen sensor grounding
Pin 45: Upstream oxygen sensor signal
Pin 2: Upstream oxygen sensor heating control
1#: To main relay power
4. Diagnosis
ECU detects the oxygen sensor circuit and ECU internal power amplifier circuit and testing circuit. If
one of the following conditions occurs, the oxygen sensor fault indicator will be set:
Battery voltage not reliable
Intake manifold absolute pressure signal not reliable
Engine coolant temperature signal not reliable
sensor
sensor
relay
Main