Mitsubishi Eclipse / Eclipse Spyder (2000-2002). Service and repair manual — part 249

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-195

STEP 4. Check connector A-21X at the MFI relay for
damage.
Q: Is the connector in good condition?

YES : Repair harness wire between MFI relay connector A-

21X terminal 1 and left bank heated oxygen sensor
(rear) connector B-23 terminal 1 because of open
circuit or short circuit to ground. Then go to Step 12.

NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection (

P.00E-2

). Then go to Step 12.

STEP 5. Check the power supply voltage at ECM connector
C-51 <M/T> or PCM connector C-52 <A/T> by backprobing.
(1) Do not disconnect the connector C-51 <M/T> or C-52 <A/

T>.

(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 26 and ground by

backprobing.

•

Voltage should be battery positive voltage.

(4) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the voltage normal?

YES : Go to Step 8.
NO : Go to Step 6.

STEP 6. Check connector C-51 at ECM <M/T> or connector
C-52 at PCM <A/T> for damage.
Q: Is the connector in good condition?

YES : Go to Step 7.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection (

P.00E-2

). Then go to Step 12.

AK000226

AK000226AB

CONNECTOR : A-21X

MFI RELAY

AKX01543

AKX01543

1

2

3 4

5 6

7 8

10 11 12 13 14 15 16 17 18 19 20 21 22 23

24 25

26 27 28 29

30 31 32 33

34 35

C-51<M/T>, C-52<A/T>
CONNECTOR HARNESS
SIDE VIEW

AF

9

AK000225

CONNECTOR : C-51<M/T>, C-52<A/T>

C-52

C-51

PCM<A/T>

ECM<M/T>

AJ

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-196

STEP 7. Check for open circuit or short circuit to ground
between left bank heated oxygen sensor (rear) connector
B-23 terminal 3 and ECM connector C-51 terminal 26 <M/T>
or PCM connector C-52 terminal 26 <A/T>.
Q: Is the harness wire in good condition?

YES : Replace the ECM or PCM. Then go to Step 12.
NO : Repair it. Then go to Step 12.

STEP 8. Check connector C-51 at ECM <M/T> or connector
C-52 at PCM <A/T> for damage.
Q: Is the connector in good condition?

YES : Go to Step 9.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection (

P.00E-2

). Then go to Step 12.

AK000214

AK000214AB

CONNECTOR : B-23

AK000225

CONNECTOR : C-51<M/T>, C-52<A/T>

C-52

C-51

PCM<A/T>

ECM<M/T>

AJ

AK000225

CONNECTOR : C-51<M/T>, C-52<A/T>

C-52

C-51

PCM<A/T>

ECM<M/T>

AJ

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-197

STEP 9. Check for harness damage between MFI relay
connector A-21X terminal 1 and left bank heated oxygen
sensor (rear) connector B-23 terminal 1.
Q: Is the harness wire in good condition?

YES : Go to Step 10.
NO : Repair it. Then go to Step 12.

STEP 10. Check for harness damage between left bank
heated oxygen sensor (rear) connector B-23 terminal 3 and
ECM connector C-51 terminal 26 <M/T> or PCM connector
C-52 terminal 26 <A/T>.
Q: Is the harness wire in good condition?

YES : Go to Step 11.
NO : Repair it. Then go to Step 12.

AK000226

AK000226AB

CONNECTOR : A-21X

MFI RELAY

AK000214

AK000214AB

CONNECTOR : B-23

AK000214

AK000214AB

CONNECTOR : B-23

AK000225

CONNECTOR : C-51<M/T>, C-52<A/T>

C-52

C-51

PCM<A/T>

ECM<M/T>

AJ

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-198

STEP 11. Check the trouble symptoms.
(1) Carry out a test drive with the drive cycle pattern. Refer to,

Procedure 6

−

Other Monitor (

P.13B-4

).

(2) Check the diagnostic trouble code (DTC).

Q: Is the DTC P0161 is output?

YES : Replace the ECM or PCM. Then go to Step 12.
NO : It can be assumed that this malfunction is intermittent.

Refer to GROUP 00, How to Use Troubleshooting/
Inspection Service Points (

P.00-6

).

STEP 12. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to,

Procedure 6

−

Other Monitor (

P.13B-4

).

(2) Check the diagnostic trouble code (DTC).

Q: Is the DTC P0161 is output?

YES : Retry the troubleshooting.
NO : The inspection is complete.

DTC P0171: System too Lean (bank 1)

System too Lean (bank 1) Circuit

•

Refer to, DTC P0201, P0203, P0205

−

Injector

Circuit (

P.13B-219

).

CIRCUIT OPERATION

•

Refer to, DTC P0201,P0203,P0205

−

Injector

Circuit (

P.13B-219

).

TECHNICAL DESCRIPTION

•

If a malfunction occurs in the fuel system, the fuel
trim value becomes too large.

•

The ECM <M/T> or PCM <A/T> checks whether
the fuel trim value is within a specified range.

DTC SET CONDITIONS

Check Area

•

Engine coolant temperature is lower than
approximately 100

°

C (212

°

F) when the engine

is started.

•

Intake air temperature is lower than 60

°

C (140

°

F) when the engine is started.

•

Under the closed loop air/fuel ratio control.

•

Intake air temperature is higher than -10

°

C (14

°

F).

•

Barometric pressure is higher than 76kPa (11
psi).

•

Volume air flow sensor output frequency is 75 Hz
or more.

Judgment Criteria

•

Long-term fuel trim has continued to be higher
than +12.5 for 5 seconds.

or

•

Short-term fuel trim has continued to be higher
than +7.4 for 5 seconds.

Check Area

•

Engine coolant temperature is lower than
approximately 100

°

C (212

°

F) when the engine

is started.

•

Intake air temperature is lower than 60

°

C (140

°

F) when the engine is started.

•

Under the closed loop air/fuel ratio control.

•

Intake air temperature is higher than -10

°

C (14

°

F).

•

Barometric pressure is higher than 76kPa (11
psi).

•

Volume air flow sensor output frequency is 75 Hz
or less.

Judgment Criteria

•

Long-term fuel trim has continued to be higher
than +12.5 for 5 seconds.

or

•

Short-term fuel trim has continued to be higher
than +12.4 for 5 seconds.

Check Area

•

Engine coolant temperature is higher than
approximately 100

°

C (212

°

F) when the engine

is started.