Mitsubishi MOTORS Lancer 2005, Workshop Manual Supplement

Page: 37 / 109

MPI <4G63>
ï
Troubleshooting
13D-32
Code No. 59 Oxygen sensor (rear) system Probable cause
Range of Check
D
More than 3 minutes passed after completion of start of engine
D The engine coolant temperature is approximately more than 80 _ C.
D Intake air temperature 0
ï
55 _ C
D The engine speed is more than 1,800
ï
3,500 r/min.
D The volumetric efficiency is 16
ï
60% or more.
D Other than the fuel cut mode
D When 0.2 seconds or more of the fuel cut passed, 30 seconds elapsed after
return.
D The air flow sensor output frequency is 81 Hz or more.
Set Conditions
D When the throttle position sensor is 4.4 V or higher, other than the engine is
idling, and other than in feedback mode, all the following states continue to
be true for 5 seconds or more: the oxygen sensor (front) output voltage is
0.5 V or higher; the oxygen sensor (rear) output voltage is less than 0.1 V;
and the oxygen sensor (rear) output voltage variation is less than 0.078 V.
D When the air/fuel ratio is forcibly turned to a rich state for 10 seconds, all
the following states continue to be true for 5 seconds or more: the oxygen
sensor (front) output voltage is 0.5 V or more; the oxygen sensor (rear)
output voltage is less than 0.1 V; and the oxygen sensor (rear) output
voltage variation is less than 0.078 V.
D The engine-A/T-ECU monitors for this condition once during the drive cycle.
D Malfunction of the oxygen sensor (rear)
D
Oxygen sensor (rear) circuit disconnection,
short-circuit, or connector contact defect
D Malfunction of the engine-A/T-ECU
OK
To the next page
OK
Check the harness between the
oxygen sensor (rear) and
engine-A/T-ECU.
NG
Repair
NG
OK
Check the following connector:
C-126
Repair
(2) NG
Check the oxygen sensor (rear).
(Refer to P.13D-100.)
NG
Replace the oxygen sensor (rear).
OK
Check the harness between the
oxygen sensor (rear) and
engine-A/T-ECU.
NG
Repair
OK
Measure at the C-130 oxygen sensor
(rear) connector.
D Using the test harness
(MB991658), connect the
connector, and measure at the
pickup harness.
D Engine: After warm-up
(1) Voltage between terminal No. 2
and earth
OK: Less than 0.5 V
(2) Voltage between terminal No. 1
and the earth
D During rapid racing
OK: 0 and 600
ï
1,000 mV
alternate.
(1) NG
Check the following connector:
C-124
NG
Repair
OK
Intermittent malfunction
(Refer to GROUP 00
ï
Points to Note
for Intermittent Malfunctions.)
OK
M.U.T.- II/III Data list
D No. 59 Oxygen sensor (rear)
(Refer to P.13D-66.)
NG
Replace the engine-A/T-ECU.
OK
Check the harness between the
oxygen sensor (rear) and
engine-A/T-ECU.
NG
Repair
OK
Measure at the C-130 oxygen sensor
(rear) connector.
D
Disconnect connector to measure
at the harness side
D Resistance between terminal No.
2 and earth.
OK: Less than 2
:
NG
Check the following connector:
C-124
NG
Repair
NG
Check the following connector:
C-130
NG
Repair
M.U.T.- II/III Data list
D No. 59 Oxygen sensor (rear)
(Refer to P.13D-66.)
OK
Intermittent malfunction
(Refer to GROUP 00
ï
Points to Note
for Intermittent Malfunctions.)