Mitsubishi FUEL Manual page 23

Code No. P0135 Oxygen sensor heater (front) system
<sensor 1>
Range of Check
D The engine coolant temperature is approx. 20_C or more.
D The oxygen sensor heater (front) remains on.
D The engine speed is 50 r/min or more.
D Battery voltage is 11 - 16 V.
Set Conditions
D The current, which flows through the oxygen sensor heater (front), is 0.2 A
or less or 3.5 A or more for six seconds.
Measure at oxygen sensor (front)
connector C-46.
D Disconnect the connector and
measure at the harness side.
D Resistance between terminals 3
and 4
OK: 4.5 - 8.0 W
OK
Check the following connector:
C-46
OK
Measure at oxygen sensor (front)
connector C-46.
D Disconnect the connector and
measure at the harness side.
D Ignition switch: ON
D Voltage between terminal 3 and
earth
OK: System voltage
OK
Measure at engine-ECU connector
C-38 <M/T> or engine-A/T-ECU
connector C-177 <A/T>.
D Measure the voltage at the
engine-ECU terminal.
D Ignition switch: ON
D Voltage between terminal 60
<M/T>, 3 <A/T> and earth
OK: System voltage
OK
Check the following connector:
C-38 <M/T>, C-177 <A/T>
OK
Check the harness wires between
the oxygen sensor (front) and the
engine-ECU <M/T> or
engine-A/T-ECU <A/T> and between
the oxygen sensor (front) and the
engine control relay.
OK
Check the trouble symptoms.
NG
Replace the engine-ECU <M/T> or
engine-A/T-ECU <A/T>.
MPI <4G6> -
Troubleshooting
NG
Replace
NG
Repair
NG
Check the following connector:
C-31
Check the harness wires between
the oxygen sensor (front) and the
engine control relay, and repair if
necessary.
NG
Check the following connector:
C-38 <M/T>, C-177 <A/T>
Check the harness wire between the
oxygen sensor (front) and the
engine-ECU <M/T> or
engine-A/T-ECU <A/T>, and repair if
necessary.
NG
Repair
NG
Repair
OK
Transient malfunction
(Refer to GROUP 00 - Points to
Note for Intermittent Malfunctions.)
Probable cause
D Malfunction of oxygen sensor heater (front)
D Open or short circuit in the oxygen sensor heater
(front) circuit or loose connector contact
D Malfunction of engine-ECU <M/T>
D Malfunction of engine-A/T-ECU <A/T>
NG
OK
NG
OK
13A-23
Repair
Repair