MPI <4G1> -
Troubleshooting
13A-20
NG
Replace the engine-ECU.
OK
Transient malfunction
(Refer to GROUP 00 - Points to
Note for Intermittent Malfunctions.)
OK
Check the trouble symptoms.
OK
Check the following connector:
B-34
Repair
NG
OK
Check the harness wire between the
oxygen sensor (front) and the
engine-ECU, and repair if necessary.
NG
Check the following connector:
B-34
NG
Repair
OK
Measure at engine-ECU connector
B-34.
D
Measure the voltage at the
engine-ECU terminal.
D
Engine: 2,500 r/min (after
warming up)
D
Voltage between terminal 76 and
earth
OK:
0 V and 0.8 V alternate.
OK
Check the harness wire between the
oxygen sensor (front) and the
engine-ECU, and repair if necessary.
OK
NG
Repair
Check the following connector:
B-34
OK
Check the harness wire between the
oxygen sensor (front) and the
engine-ECU, and repair if necessary.
NG
Replace the engine-ECU.
OK
Check the trouble symptoms.
OK
Check the harness wire between the
oxygen sensor (front) and the
engine-ECU.
NG
Repair
Repair
OK
Measure at oxygen sensor (front)
connector A-106.
D
Disconnect the connector and
measure at the harness side.
D
Resistance between terminal 2
and earth
OK:
2
W
or less
NG
Check the following connector:
B-34
NG
Check the following connector:
A-106
NG
Repair
(2) NG
Check the oxygen sensor (front).
(Refer to P.13A-80.)
NG
Replace
Repair
OK
Measure at oxygen sensor (front)
connector A-106.
D
Use the test harness
(MD998464) to connect the
connector, and measure at the
pick-up harness side.
D
Engine: 2,500 r/min (after
warming up)
(1) Voltage between terminal 2 and
earth
OK:
0.5 V or less
(2) Voltage between terminal 4 and
earth
OK:
0 V and 0.8 V alternate.
(1) NG
Check the following connector:
B-34
NG