MPI <4G63>
ï
Troubleshooting
13D-20
NG
Replace the engine-A/T-ECU.
OK
Check the trouble symptoms.
OK
Check the following connectors:
C-124, C-126
NG
Repair
OK
Check the harness wire between the
throttle position sensor and the
engine-A/T-ECU, and repair if
necessary.
Measure at the engine-A/T-ECU
connector C-126
D
Measure voltage at the
engine-A/T-ECU terminal.
D
Ignition switch: ON
D
Voltage between terminal 78 and
earth
OK:
Accelerator pedal fully re-
leased: 0.335
ï
0.935 V
Accelerator pedal fully de-
pressed: 4.4
ï
5.3 V
NG
Check the following connector:
C-126
NG
Repair
OK
From the previous page
Code No. 21 Engine coolant temperature sensor system
Probable cause
Range of Check
D
60 seconds after the ignition switch is set to the “ON” position, or after the
completion of start of engine.
Set Conditions
D
The sensor output voltage is 4.6 V or more for 4 seconds (equivalent to
ï
45
_
C or lower of engine coolant temperature)
or
D
The sensor output voltage is 0.1 V or less for 4 seconds (equivalent to
140
_
C or higher of engine coolant temperature)
D
Malfunction of the engine coolant temperature
sensor
D
Open or short circuit in the engine coolant
temperature sensor circuit or loose connector
contact
D
Malfunction of the engine-A/T-ECU
Range of Check
D
Engine: After starting
Set Condition
D
The engine coolant temperature has reduced from over 40
_
C to less than
40
_
C, and that condition has lasted for five minutes or more.
OK
To the next page
M.U.T.-
II/III
Data list
21 Engine coolant temperature
sensor
OK:
When the engine is cold,
the temperature is roughly
the same as ambient tem-
perature. If warm, it is 80
ï
120
_
C.
OK
Intermittent malfunction
(Refer to GROUP 00
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Points to
Note for Intermittent Malfunctions.)
NG
NG
Replace
OK
Check the following connector:
B-111
NG
Repair
Measure at engine coolant
temperature sensor connector
B-111.
D
Disconnect the connector and
measure at the sensor side.
D
Resistance between terminals 1
and 2
OK:
At 20
_
C of engine coolant
temperature: 2.1
ï
2.7 k
:
At 80
_
C of engine coolant
temperature:
0.26
ï
0.36 k
: