MPI <4G6> -
Troubleshooting
13A-26
Code No. P0141 Oxygen sensor heater (rear) system
<sensor 2>
Probable cause
Range of Check
D
The engine coolant temperature is approx. 20
_
C or more.
D
The oxygen sensor heater (rear) 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 (rear), is 0.2 A or
less or 3.5 A or more for six seconds.
D
Malfunction of oxygen sensor heater (rear)
D
Open or short circuit in the oxygen sensor heater
(rear) circuit or loose connector contact
D
Malfunction of engine-ECU <M/T>
D
Malfunction of engine-A/T-ECU <A/T>
NG
Replace the engine-ECU <M/T> or
engine-A/T-ECU <A/T>.
OK
Check the trouble symptoms.
OK
Transient malfunction
(Refer to GROUP 00 - Points to
Note for Intermittent Malfunctions.)
OK
Check the harness wires between
the oxygen sensor (rear) and the
engine-ECU <M/T> or
engine-A/T-ECU <A/T> and between
the oxygen sensor (rear) and the
engine control relay.
NG
Repair
OK
Check the following connector:
C-38 <M/T>, C-177 <A/T>
NG
Repair
OK
Check the harness wire between the
oxygen sensor (rear) and the
engine-ECU <M/T> or
engine-A/T-ECU <A/T>, and repair if
necessary.
Repair
NG
Check the following connector:
C-38 <M/T>, C-177 <A/T>
NG
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 <M/T> or
engine-A/T-ECU terminal <A/T>.
D
Ignition switch: ON
D
Voltage between terminal 54
<M/T>, 26 <A/T> and earth
OK:
System voltage
OK
Check the harness wires between
the oxygen sensor (rear) and the
engine control relay, and repair if
necessary.
Repair
NG
Check the following connector:
C-31
NG
OK
Measure at oxygen sensor (rear)
connector C-85.
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
Check the following connector:
C-85
NG
Repair
Measure at oxygen sensor (rear)
connector C-85.
D
Disconnect the connector and
measure at the harness side.
D
Resistance between terminals 3
and 4
OK:
11 - 18
W
NG
Replace