Mitsubishi Eclipse 1990 Service Manual page 548

Code No. (Heated Oxygen) Sensor Circuit
Malfunction (Bank Sensor 1)
[Comment]
Background
When the heated oxygen sensor begins to
becomes poor.
The engine control module forcibly
and checks the response speed of the heated oxygen sensor.
In addition, the engine control module also checks for an open circuit in the heated oxygen
sensor output line.
Check Area, Judgement Criteria
1. Check Area
Engine coolant temperature sensor: normal
Heated oxygen sensor signal voltage has continued to be 0.1
or more after the starting sequence was completed.
Engine coolant temperature is higher than
Engine speed is higher than 1200
Volumetric efficiency is not lower than 25%.
intake air temperature is
Barometric pressure is 76
Judgement Criteria
Input voltage supplied to the engine control module interface circuit is not lower than
4.5 when 5 is applied to the heated oxygen sensor output line via a resistor.
2. Check Area
Engine coolant temperature sensor: Normal
Engine temperature is not lower than
Engine speed is between 1500 and 3000
Engine speed is between
Volumetric efficiency is 25
Intake air temperature is
Barometric pressure is 76
Under the closed loop air-fuel control.
Monitoring time: 6
Judgement Criteria
When the air-fuel ratio is forcibly changed (lean to rich and rich to lean), the heated
oxygen sensor signal doesn't provide response within 1.2 sec.
Monitored only once per
Check the heated oxygen sensor
(front). (Refer to
NG
Replace
ENGINE (TURBO)
AND ENGINE>
the sensor signal response
the mixture to make it leaner and richer,
or higher
(11 psi.) or higher.
and 3000
60%.
or higher
(11 psi.) or higher.
Check trouble symptom.
Check the harness wire between the
ECM and the heated
(front) connector.
Replace the oxygen sensor (front).
Check trouble symptom.
Replace the ECM.
TSB Revision
Troubleshooting
Heated oxygen sensor deteriorated
Open circuit in heated oxygen
l
Engine control module failed
or lower for 3 min
N G
OK
NG
NG
sensor
OK
I
NG
i n e
Repair
Repair
. .
, ,
. .