Mitsubishi Galant 9G. Manual — part 970
MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS
TSB Revision
MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>
13B-180
DTC P0125: Insufficient Coolant Temperature for Closed Loop Fuel Control
CAUTION
If DTC P0125 has been set, TCL related DTC
U1120 is also set. After P0125 has been diag-
nosed, don't forget to erase DTC U1120.
YELLO
W
-GREEN
BLA
CK
AK302836
ENGINE COOLANT
TEMPERATURE SENSOR
POWERTRAIN CONTROL MODULE(PCM)
5 V
93
2
B-104
(MU802406)
69
1
Engine Coolant Temperature Sensor Circuit
1 2
B-21
B-22
52
51
53 54 55 56
57
58 59 60 61 62
63
64 65 66 67 68 69
70
71 72 73 74 75
76
77 78 79 80 81 82
83
100
99
92
91
93 94 95
96 97 98
101 102 103 104
105 106 107 108
109 110 111 112 113
AK303036
CONNECTOR: B-104
AB
B-104 (B)
ENGINE
COOLANT
TEMPERATURE
SENSOR
THROTTLE
BODY
MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS
TSB Revision
MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>
13B-181
.
CIRCUIT OPERATION
• 5-volt voltage is applied to the engine coolant
temperature sensor output terminal (terminal No.
1) from the PCM (terminal No. 93) via the resistor
in the PCM. The ground terminal (terminal No. 2)
is grounded with PCM (terminal No. 69).
• The engine coolant temperature sensor is a neg-
ative temperature coefficient type of resistor. It
has the characteristic that when the engine cool-
ant temperature rises the resistance decreases.
• The engine coolant temperature sensor output
voltage increases when the resistance increases
and decreases when the resistance decreases.
.
TECHNICAL DESCRIPTION
• The engine coolant temperature sensor converts
the engine coolant temperature to a voltage and
outputs it.
• The PCM checks whether this voltage is within a
specified range.
.
DESCRIPTIONS OF MONITOR METHODS
• Engine coolant temperature sensor output volt-
age drops from over 40
°C (104°F) to under 40°C
(104
°F) and keeps under 40°C (104°F) for 5 min-
utes.
• Engine coolant temperature sensor output volt-
age does not reach close loop enable tempera-
ture within specified period when engine coolant
temperature sensor output voltage at engine start
is under 7
°C (45°F).
.
MONITOR EXECUTION
Continuous
.
MONITOR EXECUTION CONDITIONS
(Other monitor and Sensor)
Other Monitor (There is no temporary DTC stored
in memory for the item monitored below)
• Not applicable
Sensor (The sensor below is determined to be
normal)
• Mass airflow sensor
• Engine coolant temperature sensor
• Intake air temperature sensor
.
AK303013
CONNECTORS: B-21, B-22
PCM
AB
AIR CLEANER
B-22 (B)
B-21 (B)
MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS
TSB Revision
MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>
13B-182
DTC SET CONDITIONS <Range/Performance problem - low input (time to reach
closed loop temperature)>
Logic Flow Chart
.
Check Conditions, Judgement Criteria
• About 60 − 300 seconds have passed for the
engine coolant temperature to rise to about 7
°C
(44.6
°F) after starting sequence was completed.
• However, time is not counted when fuel is shut
off.
.
START
END
YES
NO
NO
YES
MALFUNCTION
GOOD
TIME HAVE PASSED
AFTER STARTING?*
ENGINE
COOLANT
TEMP.
TEMP. WHERE
CLOSED LOOP
STARTS
>
MONITORING
CONDITIONS?
NO
YES
*: SEE DTC SET CONDITIONS-SET CONDITIONS, JUDGMENT CRITERIA
AK302385
MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS
TSB Revision
MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>
13B-183
DTC SET CONDITIONS <Range/Performance problem - drift>
Logic Flow Chart
.
Check Conditions, Judgement Criteria
• Engine coolant temperature decreases from
higher than 40
°C (104°F) to lower than 40°C
(104
°F).
• Then the engine coolant temperature has contin-
ued to be 40
°C (104°F) or lower for 5 minutes.
.
OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function
− OBD-II Drive Cycle −
Procedure 6
.
.
TROUBLESHOOTING HINTS (The most
likely causes for this code to be set are:)
• Engine coolant temperature sensor failed.
• Harness damage in engine coolant temperature
sensor circuit or connector damage.
• PCM failed.
START
END
NO
NO
YES
YES
MALFUNCTION
GOOD
UNDER 40˚C (107˚F)
300SECS HAVE PASSED?
NO
YES
OVER 40˚C (107˚F)
YES
OVER 40˚C (107˚F)
NO
AK302387
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст