Mitsubishi Eclipse. Manual — part 444

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-319

.

CIRCUIT OPERATION

• Power is supplied from the MFI relay (terminal

No. 4) to the right bank heated oxygen sensor
(rear) heater.

• The ECM (terminal No. 27) <M/T> or PCM (termi-

nal No. 27) <A/T> controls continuity to the right
bank heated oxygen sensor (rear) heater by turn-
ing the power transistor in the ECM <M/T> or
PCM <A/T> "ON" and "OFF."

.

BACKGROUND

• The ECM <M/T> or PCM <A/T> checks whether

the heater current is within a specified range
when the heater is energized.

.

DESCRIPTIONS OF MONITOR METHODS
Right bank heated oxygen sensor heater (rear) cur-

rent is out of specified range when engine coolant
temperature is over 20

°C (68°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)

• Engine coolant temperature sensor

.

AK300075

RIGHT BANK
HEATED OXYGEN
SENSOR (REAR)

CONNECTOR: B-28

AB

B-28 (GR)

AK300121

MFI RELAY

CONNECTOR: A-18X

AB

A-18X

AK300091

CONNECTOR: C-51 <M/T>

ECM

AF

C-51 (GR)

AK300244

CONNECTOR: C-52 <A/T>

AC

PCM

C-52 (GR)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-320

DTC SET CONDITIONS

Logic Flow Chart

.

Check Conditions

• 60 seconds have elapsed from the start of the

previous monitoring.

• Engine coolant temperature is higher than 20°C

(68

°F).

• While the right bank heated oxygen sensor (rear)

heater is on.

• Battery positive voltage is at between 11 and 16.5

volts.

Judgment Criteria

• Heater current of the right bank heated oxygen

sensor (rear) heater has continued to be lower
than 0.16 ampere or higher than 5.0 ampere for 4
seconds.

.

OBD-ll DRIVE CYCLE PATTERN
Refer to , Diagnostic Function

− OBD-ll Drive Cycle −

Procedure 6

− Other Monitor

P.13B-7

.

.

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

• Open or shorted right bank heated oxygen sen-

sor (rear) heater circuit harness damage, or con-
nector damage.

• Open circuit in right bank heated oxygen sensor

(rear) heater.

• ECM failed. <M/T>

• PCM failed. <A/T>

START

END

YES

YES

YES

YES

NO

NO

NO

NO

MALFUNCTION

GOOD

CONTINUOUS

FAILURE FOR 4secs

MONITORING

CONDITIONS

CURRENT < 0.16A

CURRENT > 5.0A

AK301443

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-321

DIAGNOSIS

Required Special Tool:

• MB991316: Test Harness

STEP 1. Check connector B-28 at the right bank heated
oxygen sensor (rear) 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.

AK300429

1

2

3

4

RIGHT BANK
HEATED OXYGEN
SENSOR (REAR)

CONNECTOR: B-28

AB

B-28 (GR)

HARNESS CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-322

STEP 2. Check the right bank heated oxygen sensor (rear).
(1) Disconnect right bank heated oxygen sensor (rear)

connector B-28 and connect test harness special tool,
MB991316, to the connector on the right bank heated
oxygen (rear) sensor side.

(2) Measure the resistance between heated oxygen sensor

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

Standard value: 11

− 18 ohms [at 20°C (68°F)]

Q: Is the resistance between 11 and 18 ohms?

YES : Go to Step 3.
NO : Replace the right bank heated oxygen sensor (rear).

Then go to Step 12.

AK300429

1

2

3

4

RIGHT BANK
HEATED OXYGEN
SENSOR (REAR)

CONNECTOR: B-28

AB

B-28 (GR)

HARNESS CONNECTOR:
COMPONENT SIDE

AKX01624 AB

MB991316

HEATED
OXYGEN
SENSOR
EQUIPMENT
SIDE
CONNECTOR

BLUE

RED