Mitsubishi 380. Manual — part 522

MULTIPORT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MPI)

13A-180

STEP 1. Using diagnostic tool, check data list item AC:
Heated Oxygen Sensor Bank 1, Sensor 1 (right front).

CAUTION

To prevent damage to diagnostic tool, always turn the igni-
tion switch to the "LOCK" (OFF) position before connect-
ing or disconnecting diagnostic tool .
(1) Connect diagnostic tool to the data link connector.
(2) Start the engine and run at idle.
(3) Ensure engine is at running temperature (80

° C or higher).

(4) Set diagnostic tool to the data reading mode for item AC,

Heated Oxygen Sensor Bank 1, Sensor 1 (right front).

• Warming up the engine. When the engine is revved, the

output voltage should alternate between 0 and 0.6 to 1.0
volts.

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

Q: Is the sensor operating properly?

YES : It can be assumed that this malfunction is intermittent.

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

− How to

Cope with Intermittent Malfunctions

P.00-14

.

NO : Then go to Step 2.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MPI)

13A-181

STEP 2. Measure the sensor output voltage at
ENGINE-ECU connector B-20 by using ENGINE-ECU
check harness special tool MB992044.
(1) Disconnect the all ENGINE-ECU connectors and connect

ENGINE-ECU check harness special tool MB992044
between the separated connectors.

(2) Start the engine and run at idle.
(3) Ensure engine is at running temperature (80

° C or higher).

(4) Measure the voltage between terminal No. 45 and ground.

• Warm engine. When the engine is revved, the output

voltage should alternate between 0 and 0.6-1.0 volts.

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

Q: Is the measured voltage cycling within the specified

range?
YES : Go to Step 6.
NO : Then go to Step 3.

16DB400A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

03DB199A

B-20 HARNESS

CONNECTOR

MULTIPORT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MPI)

13A-182

STEP 3. Check harness connector B-09 at right bank
heated oxygen sensor (front) and connector B-20 at
ENGINE-ECU for damage.
Q: Is the harness connector in good condition?

YES : Go to Step 4.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Then go to Step 7.

1

2

3

4

AK303048

B-09 (B)

CONNECTOR: B-09

THROTTLE BODY

RIGHT BANK

HEATED OXYGEN

SENSOR (FRONT)

AB

HARNESS

CONNECTOR:

COMPONENT SIDE

16DB400A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

MULTIPORT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MPI)

13A-183

STEP 4. Check for open circuit between right bank heated
oxygen sensor (front) connector B-09 (terminal No. 1) and
ENGINE-ECU connector B-20 (terminal No. 45).
Q: Is the harness wire in good condition?

YES : Go to Step 5.
NO : Repair or replace it. Then go to Step 7.

1

2

3

4

AK303048

B-09 (B)

CONNECTOR: B-09

THROTTLE BODY

RIGHT BANK

HEATED OXYGEN

SENSOR (FRONT)

AB

HARNESS

CONNECTOR:

COMPONENT SIDE

16DB400A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER