Mitsubishi 380. Manual - part 536

MULTIPORT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MPI)

13A-236

STEP 5. Check for open circuit between left bank heated 
oxygen sensor (front) connector B-25 (terminal No. 2) and 
ENGINE-ECU connector B-20 (terminal No. 14).
Q: Is the harness wire in good condition?

YES : Go to Step 6.
NO :  Repair or replace it. Then go to Step 7.

AK303071

1

2

3

4

LEFT BANK

HEATED OXYGEN

SENSOR (FRONT)

CONNECTOR: B-25

B-25 (B)

AB

HARNESS

CONNECTOR:

COMPONENT SIDE

16DB400A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

MULTIPORT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MPI)

13A-237

STEP 6. Using diagnostic tool, check data list item AE: 
Heated Oxygen Sensor Bank 2, Sensor 1 (left 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 AE, 

Heated Oxygen Sensor Bank 2, Sensor 1 (left 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 :  Replace the sensor. Then go to Step 7.

STEP 7. Test the EOBD drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to 

Diagnostic Function 

− EOBD Drive Cycle − 

P.13A-11

.

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

Q: Is DTC P0154 set?

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

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MPI)

13A-238

DTC P0156: Heated Oxygen Sensor Circuit (bank 2, sensor 2).

.

CIRCUIT OPERATION

• A voltage corresponding to the oxygen concen-

tration in the exhaust gas is sent to the 
ENGINE-ECU (terminal No. 30) from the output 
terminal (terminal No. 1) of the left bank heated 
oxygen sensor (rear).

• Terminal No. 2 of the left bank heated oxygen 

sensor (rear) is grounded with ENGINE-ECU (ter-
minal No. 29).

.

TECHNICAL DESCRIPTION

• The output signal of the left bank heated oxygen 

sensor (front) is compensated by the output sig-
nal of the left bank heated oxygen sensor (rear).

• The ENGINE-ECU checks for an open circuit in 

the left bank heated oxygen sensor (rear) output 
line.

.

DTC SET CONDITIONS

Check Conditions

• Battery voltage < 11.02 volts

• Engine coolant temperature is higher than 80°C. 

Judgment Criteria

• Signal check.

• MIL is activated after 2 Drive cycles.

• No limp home.

.

EOBD DRIVE CYCLE PATTERN

Refer to Diagnostic Function 

− EOBD Drive Cycle − 

P.13A-11

.

.

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

• Left bank heated oxygen sensor (rear) failed.

• Short circuit in left bank heated oxygen sensor 

(rear) output line to heater circuit ground. 

• Wiring harness or connector damage.

• Refer to component locations GROUP-

70

• Refer to configuration diagrams GROUP-

80

• Refer to circuit diagrams GROUP-

90

DIAGNOSIS

Required Special Tools:

• : Diagnostic tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

AK303079

CONNECTOR: B-24

AB

LEFT BANK

HEATED OXYGEN

SENSOR (REAR)

B-24 (GR)

16DB400A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

MULTIPORT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MPI)

13A-239

• MB992044:  ENGINE-ECU Check Harness

STEP 1. Using diagnostic tool, check data list item AF: Left 
Bank Heated Oxygen Sensor Bank 2, Sensor 2 (left rear).

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) Set diagnostic tool  to the data reading mode for item AF, 

Heated Oxygen Sensor Bank 2, Sensor 2 (left rear).

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

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

(4) 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 :  Go to Step 2.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827