Mitsubishi MOTORS Space Runner 1999 Workshop Manual Supplement page 81

13D-16
Code No. 21 Engine coolant temperature sensor system
Range of Check
D Ignition switch: ON
D Excluding 60 seconds after the ignition switch is turned to ON or immediately
after the engine starts.
Set conditions
D Sensor output voltage is 4.6 V or more (corresponding to an engine coolant
temperature of - 45_C or less) for 4 seconds.
or
D Sensor output voltage is 0.1 V or less (corresponding to an engine coolant
temperature of 140_C or more) for 4 seconds.
Range of Check
D Ignition switch: ON
D Engine speed is approx. 50 r/min or more
Set conditions
D The sensor output voltage increases from 1.6 V or less (corresponding to an
engine coolant temperature of 40_C or more) to 1.6 V or more (corresponding
to an engine coolant temperature of 40_C or less).
D After this, the sensor output voltage is 1.6 V or more for 5 minutes.
Check the engine coolant temperature
sensor. (Refer to P.13D-86.)
OK
Measure at the engine coolant temper-
ature sensor connector A-80.
D Disconnect the connector, and
measure at the harness side.
D Voltage between 1 and earth
(Ignition switch: ON)
OK: 4.5 - 4.9 V
D Continuity between 2 and earth
OK: Continuity
OK
Check the following connector:
A-80
NG
Repair
MPI -
Troubleshooting
NG
Replace
NG
Check the following connector:
B-51 <M/T>, B-112 <A/T>
Check trouble symptom.
Check the harness wire between the
engine-ECU <M/T>
A/T-ECU <A/T> and the engine coolant
temperature sensor connector.
Replace the engine-ECU <M/T> or en-
gine-A/T-ECU <A/T>.
OK
Check trouble symptom.
Replace the engine-ECU <M/T> or en-
gine-A/T-ECU <A/T>.
Probable cause
D Malfunction of the engine coolant temperature sensor
D Improper
short-circuited harness wire of the engine coolant
temperature sensor circuit
D Malfunction
engine-A/T-ECU <A/T>
NG
Repair
OK
NG
NG
Repair
or engine-
OK
NG
connector contact, open circuit
of the engine-ECU <M/T>
or
or