Mitsubishi Lancer Evolution-VII Workshop Manual page 717

DIAGNOSTIC TROUBLE CODE INSPECTION PROCEDURE
Code No. P0100 Air flow sensor system
Inspection Range
D Engine speed: More than 500 r/min
Evaluation Conditions
D The sensor output frequency is less than 3 Hz for 4 seconds.
MUT-II Data list
D No. 12 Air flow sensor
(Refer to P.13A-102.)
NG
Check the following connector:
B-31
OK
Measure at the B-31 air flow sensor
connector.
D Disconnect the connector to
measure at the harness side
(1) Voltage between terminal No. 3
and earth
(Ignition switch: ON)
OK: 4.9 - 5.1 V
(2) Voltage between terminal No. 4
and earth
(Ignition switch: ON)
OK: System voltage
(3) Resistance between terminal No.
5 and earth
OK: Less than 2 Ω
OK
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MPI -
Troubleshooting
OK
Intermittent malfunction
(Refer to GROUP 00 - Points to Note
for Intermittent Malfunctions.)
NG
Repair
(1) NG
Measure at the C-115 engine-ECU
connector.
D Measure the voltage of the
engine-ECU terminal.
D Ignition switch: ON
D Voltage between terminal No. 90
and earth.
OK: 4.9 - 5.1 V
Check the following connector:
C-115
Check the harness between the air
flow sensor and engine-ECU.
D Check for short-circuit of the
output wire.
MUT-II Data list
D No. 12 Air flow sensor
(Refer to P.13A-102.)
Intermittent malfunction
(Refer to GROUP 00 - Points to Note
for Intermittent Malfunctions.)
(2) NG
Check the following connector:
B-11X
Check the harness between the air
flow sensor and engine control relay.
D Check for power cable
disconnection and short-circuit.
(3) NG
Check the following connector:
C-115
Check the harness between the air
flow sensor and engine-ECU.
D Check for ground wire
disconnection and damage.
MUT-II Data list
D No. 12 Air flow sensor
(Refer to P.13A-102.)
Intermittent malfunction
(Refer to GROUP 00 - Points to Note
for Intermittent Malfunctions.)
Probable cause
D Air flow sensor malfunction
D Air flow sensor circuit disconnection, short-circuit,
or connector contact defect
D Engine-ECU malfunction
OK
NG
NG
OK
NG
OK
NG
OK
NG
OK
NG
OK
NG
OK
NG
OK
13A-13
Check the following connector:
C-115
OK NG
Repair
Check and repair the harness between
the air flow sensor and engine-ECU.
D Check for disconnection of the
output wire.
Repair
Repair
Replace engine-ECU.
Repair
Repair
Repair
Replace engine-ECU.