Mitsubishi MOTORS Space Runner 1999 Workshop Manual Supplement page 78

Code No. 12 Air flow sensor system
Range of Check
D Engine speed is 500 r/min or more.
Set conditions
D Sensor output frequency is 3 Hz or less for 4 seconds.
Measure at the air flow sensor con-
nector A-07.
D Connect the connector. (Use
the test harness: MB991709)
1. Voltage between 3 and earth
(Engine: Idling)
OK: 2.2 - 3.2 V
2. Voltage between 7 and earth
OK: 0 - 1 V (Engine: idling)
6 - 9 V (2,000 r/min)
OK
Replace the engine-ECU <M/T>
or engine-A/T-ECU <A/T>.
MPI -
Troubleshooting
1. NG
Measure at the air flow sensor con-
nector A-07.
D Disconnect the connector and
measure at the harness side.
1. Voltage between 4 and earth
(Ignition switch: ON)
OK: System voltage
2. Voltage between 3 and earth
2. NG (Ignition switch: ON)
OK: 4.8 - 5.2 V
3. Continuity between 5 and earth
OK: Continuity
OK
Check the following connector:
A-07
OK
Check trouble symptom.
NG
Replace the air flow sensor.
Measure at the engine-ECU
connector B-54 <M/T> or the
engine-A/T-ECU connector
B-113 <A/T>.
D Connect the connector.
D Voltage between 19 and earth
(Ignition switch: ON)
OK: 6 - 9 V
OK
Check the following connector:
B-54 <M/T>, B-113 <A/T>
OK
Check trouble symptom.
NG
Replace the engine-ECU <M/T>
or engine-A/T-ECU <A/T>.
Probable cause
D Malfunction of the air flow sensor
D Improper connector
short-circuited harness wire of the air flow sensor
D Malfunction of the
engine-A/T-ECU <A/T>
1. NG
Check the harness wire between
the air flow sensor and control relay
connector, and repair if necessary.
2, 3.
NG
Check the following connector:
B-51 <M/T>, B-112 <A/T>
OK
Check trouble symptom.
NG
Check the harness wire between
the engine-ECU <M/T> or engine-
A/T-ECU <A/T> and air flow sensor
connector.
OK
NG
Repair
Replace the engine-ECU <M/T>
or engine-A/T-ECU <A/T>.
NG
Check the following connector:
A-07
OK
Check trouble symptom.
NG
Replace the air flow sensor.
NG
Repair
13D-13
contact, open circuit or
engine-ECU <M/T> or
NG
Repair
NG
Repair
NG
Repair