Mitsubishi FUEL Manual page 27

Code No. P0170 Abnormal fuel system
Range of Check
D Engine: Being learning the air/fuel ratio
Set Conditions
D Ten seconds or more have been passed while the fuel injection amount
compensation value is too low.
or
D Ten seconds or more have been passed while the fuel injection amount
compensation value is too high.
MUT-II Data list
13 Intake air temperature sensor (Refer to P.13A-75.)
MUT-II Data list
21 Engine coolant temperature sensor (Refer to P.13A-75.)
MUT-II Data list
25 Barometric pressure sensor (Refer to P.13A-75.)
Check the injector (Refer to P.13A-93*.)
Check the following connectors:
C-34 <M/T>, C-177 <A/T>, B-02, B-03, B-05, B-36
Check the harness wire between the engine-ECU <M/T> or
engine-A/T-ECU <A/T> and the injector connector.
Check the fuel pressure (Refer to P.13A-85*.)
MUT-II Data list
81 Long-term fuel compensation (Refer to P.13A-75.)
D Is fuel trim more or less than zero?
Less than zero
No
MUT-II Data list
12 Volume air flow sensor
(Refer to P.13A-75.)
D Does the tester indi-
cate more than the
standard value?
Yes
Replace the volume air
flow sensor.
NOTE:
*: Refer to the '97 GALANT Workshop Manual (Pub. No. PWDE9611)
MPI <4G6> -
OK
OK
OK
OK
OK
OK
OK
D Check for fuel leaks
from injector.
D Check for entry of
foreign matter (water,
kerosene, etc.) into the
fuel.
OK
Replace the engine-ECU
<M/T> or engine-A/T-ECU
<A/T>.
Troubleshooting
Probable cause
D Incorrect fuel pressure
D Malfunction of fuel supply system
D Malfunction of oxygen sensor (front)
D Malfunction of intake air temperature sensor
D Malfunction of barometric pressure sensor
D Malfunction of air flow sensor
D Malfunction of engine-ECU <M/T>
D Malfunction of engine-A/T-ECU <A/T>
NG
Check the intake air temperature sensor system. (Refer to P.13A-14,
INSPECTION PROCEDURE FOR DIAGNOSTIC TROUBLE
CODE P0110.)
NG
Check the engine coolant temperature sensor system. (Refer to
P.13A-16, INSPECTION PROCEDURE FOR DIAGNOSTIC
TROUBLE CODE P0115.)
NG
Check the barometric pressure sensor system. (Refer to P.13A-12,
INSPECTION PROCEDURE FOR DIAGNOSTIC TROUBLE
CODE P0105.)
NG
Replace
NG
Repair
NG
Repair
More than
zero
Check if air was drawn into
the intake system.
OK
MUT-II Data list
12 Volume air flow sensor
(Refer to P.13A-75.)
D Does the tester indi-
cate less than the
standard value?
Yes
Replace the volume air
flow sensor.
13A-27
NG
Repair
No
D Check for clogging of
the injector.
D Check for clogging of
the fuel filter and fuel
line.
D Check the fuel pump
(insufficient discharge
rate.)
D Check for exhaust
leaks (oxygen sensor
installation section,
cracks in exhaust
manifold, cracks in
front pipe, etc.).
D Check for entry of
foreign matter (water,
kerosene, etc.) into the
fuel.
OK
Replace the engine-ECU
<M/T> or engine-A/T-ECU
<A/T>.