Mitsubishi Eclipse / Eclipse Spyder (2000-2002). Service and repair manual — part 107

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-127

CIRCUIT OPERATION

•

Power is supplied from the MFI relay (terminal 1)
to the heated oxygen sensor (front) heater.

•

The ECM (terminal 60) <M/T> or PCM (terminal
3) <A/T> controls continuity to the heated oxygen
sensor (front) heater by turning the power
transistor in the ECM <M/T> or PCM <A/T> "ON"
and "OFF."

TECHNICAL DESCRIPTION

•

The ECM <M/T> or PCM <A/T> checks whether
the heater current is within a specified range
when the heater is energized.

DTC SET CONDITIONS

Check Conditions

•

Engine coolant temperature is higher than 20

°

C

(68

°

F).

•

While the heated oxygen sensor (front) heater is
on.

•

Battery positive voltage is at between 11 and 16
volts.

Judgment Criteria

•

Heater current of the heated oxygen sensor
(front) heater has continued to be lower than 0.2
ampere or higher than 3.5 ampere for 6 seconds.

•

One monitor during one drive cycle

TROUBLESHOOTING HINTS (The most likely
causes for this code to be set are:)

•

Open or shorted heated oxygen sensor (front)
heater circuit.

•

Open circuit in heated oxygen sensor (front)
heater.

•

ECM failed. <M/T>

•

PCM failed. <A/T>

DIAGNOSIS

Required Special Tools
MD998464: Test Harness

ACX02476

CONNECTOR : B-17

HEATED OXYGEN
SENSOR (FRONT)

AD

AK000280

C-49

C-56

ECM<M/T>
OR
PCM<A/T>

CONNECTORS:C-56<M/T>,C-50<A/T>

BG

AK000226

AK000226AB

CONNECTOR : A-21X

MFI RELAY

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-128

STEP 1. Check connector B-17 at the heated oxygen
sensor (front) for damage.
Q: Is the connector in good condition?

YES : Go to Step 2.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection (

P.00E-2

). Then go to Step 12.

STEP 2. Check the heated oxygen sensor (front).
(1) Disconnect heated oxygen sensor (front) connector B-17

and connect test harness special tool, MD998464, to the
connector on the heated oxygen (front) sensor side.

(2) Measure the resistance between heated oxygen sensor

connector terminal 1 (red clip) and terminal 3 (blue clip).

Standard value: 4.5

−

8.0 ohm [at 20

°

C (68

°

F)]

Q: Is the resistance normal?

YES : Go to Step 3.
NO : Replace the heated oxygen sensor (front). Then go to

Step 12.

STEP 3. Check the power supply voltage at heated oxygen
sensor (front) harness side connector B-17.
(1) Disconnect the connector B-17 and measure at the harness

side.

(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 1 and ground.

•

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 5.
NO : Go to Step 4.

AK000272AB

AK000272

CONNECTOR : B-17

ACX02476

CONNECTOR : B-17

HEATED OXYGEN
SENSOR (FRONT)

AD

AKX01624

HEATED
OXYGEN
SENSOR
EQUIPMENT
SIDE
CONNECTOR

MD998464

BLUE

RED

AC

AKX01498

B-17 HARNESS
SIDE CONNECTOR

AH

2

1

4

3

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-129

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 heated oxygen sensor (front)
connector B-17 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-56 <M/T> or PCM connector C-50 <A/T> by backprobing.
(1) Do not disconnect the connector C-56 <M/T> or C-50 <A/

T>.

(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 60 <M/T> or 3 <A/T>

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-56 at ECM <M/T> or connector
C-50 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

AK000289

<M/T>

C-56 CONNECTOR
HARNESS SIDE VIEW

51 52 53 54 55 56

57 58 59 60 61 62

AC

AK000290

1

2

3 4

5 6

7 8

9 10 11 1213 141516 17 1819 20 21 2223

24 25

2627 2829

30 3132 33

3435

AD

C-50 CONNECTOR
HARNESS SIDE VIEW

<A/T>

AK000280

C-49

C-56

ECM<M/T>
OR
PCM<A/T>

CONNECTORS:C-56<M/T>,C-50<A/T>

BG

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-130

STEP 7. Check for open circuit or short circuit to ground
between heated oxygen sensor (front) connector B-17
terminal 3 and ECM connector C-56 terminal 60 <M/T> or
PCM connector C-50 terminal 3 <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-56 at ECM <M/T> or connector
C-50 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.

AK000272AB

AK000272

CONNECTOR : B-17

AK000280

C-49

C-56

ECM<M/T>
OR
PCM<A/T>

CONNECTORS:C-56<M/T>,C-50<A/T>

BG

AK000280

C-49

C-56

ECM<M/T>
OR
PCM<A/T>

CONNECTORS:C-56<M/T>,C-50<A/T>

BG