Mitsubishi 380. Manual - part 544

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MFI)

13A-268

DTC P0174: System too Lean (bank 2)

.

CIRCUIT OPERATION

• Multiplicative or Additive adaption performed by 

ENGINE-ECU. 

.

TECHNICAL DESCRIPTION

• If a malfunction occurs in the fuel system, the fuel 

trim value becomes too large.

• The ECU checks whether the fuel trim value is 

within a specified range.

.

DTC SET CONDITIONS

Check Conditions

• Bank 2 too lean

Judgment Criteria

• MIL on 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:)

• Injector (Number 2, 4, 6) malfunctioning.

• Incorrect fuel pressure.

• Air drawn in from gaps in gasket, seals, etc.

• Use of incorrect or contaminated fuel.

• 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

STEP 1. Check for intake system vacuum leak.

Q: Are there any abnormalities?

YES : Repair it. Then go to Step 4.
NO :  Go to Step 2.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MFI)

13A-269

STEP 2. Using diagnostic tool , check actuator test items  
02, 04, 06: Injector.

CAUTION

To prevent damage to diagnostic tool , always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting diagnostic tool .
(1) Connect diagnostic tool to the data link connector. Refer to 

Actuator Test Table 

P.13A-644

(2) Start the engine and run at idle.
(3) Set diagnostic tool to the Actuator Test mode for MPI - 

Items 02, 04, 06: Injector.

(4) Warm up the engine to normal operating temperature: 80

°C 

to 95

°C.

(5) Perform Actuator test on each injector.
(6) Conduct a Power Balance test on each cylinder. Refer to 

On-Vehicle Service - Injector Check 

P.13A-670

.

Q: Is each injector operating properly?

YES : YES: Go to Step 3.
NO :  Refer to On-Vehicle Service - Injector Check 

P.13A-670

. If injector is malfuctioning replace and go 

to Step 3.

STEP 3. Check the fuel pressure.
Refer to On-vehicle Service 

− Fuel Pressure Test 

P.13A-661

.

Q: Is the fuel pressure normal?

YES : Go to Step 4.
NO :  Repair it. Then go to Step 4.

STEP 4. 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 P0174 set?

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

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MFI)

13A-270

DTC P0175: System too Rich (bank 2)

.

CIRCUIT OPERATION

• Multiplicative or Additive adaption performed by 

ENGINE-ECU. 

.

TECHNICAL DESCRIPTION

• If a malfunction occurs in the fuel system, the fuel 

trim value becomes too small.

• The ECU checks whether the fuel trim value is 

within a specified range.

.

DTC SET CONDITIONS

Check Conditions

• Bank 2 too rich.

Judgment Criteria

• MIL on 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:)

• Injector (Number 2, 4, 6) malfunctioning.

• Incorrect fuel pressure.

• 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

STEP 1. Using diagnostic tool , check actuator test items 
02, 04, 06: Injector.

CAUTION

To prevent damage to diagnostic tool , always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting diagnostic tool .
(1) Connect diagnostic tool to the data link connector. Refer to 

Actuator Test Table 

P.13A-644

(2) Start the engine and run at idle.
(3) Set diagnostic tool to the Actuator Test mode for MPI - 

Items 02, 04, 06: Injector.

(4) Warm up the engine to normal operating temperature: 80

°C 

to 95

°C.

(5) Perform Actuator test on each injector.
(6) Conduct a Power Balance test on each cylinder. Refer to 

On-Vehicle Service - Injector Check 

P.13A-670

.

Q: Is each injector operating properly?

YES : YES: Go to Step 2.
NO :  Refer to On-Vehicle Service - Injector Check 

P.13A-670

. If injector is malfuctioning replace and go 

to Step 3.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MFI)

13A-271

STEP 2. Check the fuel pressure.
Refer to On-vehicle Service 

− Fuel Pressure Test 

P.13A-661

.

Q: Is the fuel pressure normal?

YES : Go to Step 3.
NO :  Repair it. Then go to Step 3.

STEP 3. 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 P0175 set?

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