This fuel system is designed with consideration for
global environment protection to ensure safety at a
collision, reduce weight, and improve reliability and
quality. The system has the following features.

• A quick-joint connector of a plastic tube is used

for the fuel high-pressure hoses in the engine
compartment to reduce the permeation of fuel
evaporative emission.

• The surface of underfloor fuel pipes is coated

with 1 mm (0.04 inch) thickness of plastic to
improve resistance to corrosion and chipping.

• The rubber boot is employed for the filler port

mounting part of fuel filler neck to protect fuel filler
neck in case of collision.

CONSTRUCTION DIAGRAM

FUEL SUPPLY DIAGNOSIS

INTRODUCTION

M1135004000463

The fuel system is used to supply an appropriate fuel
mixture to the engine. The system consists of the
fuel tank, fuel filter, fuel pump and fuel pipes. An
evaporative emission system is provided to prevent
evaporated fuel from escaping into the atmosphere.

Engine malfunctions caused by insufficient fuel sup-
ply and evaporative emission system operation mal-
functions can be caused by faults in the vapor line,
fuel pipe, hose, or fuel tank pressure control valve,
etc.

TROUBLESHOOTING STRATEGY

M1135004100396

Use these steps to plan your diagnostic strategy. If
you follow them carefully, you will be sure to find
most of the fuel supply faults.
1. Gather information from the customer.

2. Verify that the condition described by the

customer exists.

3. Find the malfunction by following the Symptom

Procedure.

4. Verify malfunction is eliminated.

AC709107

Fuel rail

Fuel injector
return pipe

Fuel pipe

Fuel pump module

Evaporative
emission
canister

Fuel tank

Fuel level sensor (sub)

Fuel high-pressure hose

MPI delivery pipe
pressure regulator

Filler neck boots

Fuel injector

FUEL SUPPLY DIAGNOSIS

TSB Revision

FUEL SUPPLY

13B-3

SYMPTOM PROCEDURES

M1135004800414

Inspection Procedure 1 : Engine Malfunctions Due to Insufficient Fuel Supply

TROUBLESHOOTING HINTS (The most likely causes for

this case:)

• Fuel injector failed.
• Open or shorted fuel injector circuit, or loose connector.
• Bent, twisted or clogged fuel main pipe or fuel high-pres-

sure hose.

• Malfunction of the fuel tank pump and gauge assembly.

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)

• MB991824: V.C.I.
• MB991827: M.U.T.-III USB Cable
• MB991910: M.U.T.-III Main Harness A

STEP 1. Using scan tool MB991958, read the MFI system
diagnostic trouble code.

CAUTION

To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Ensure that the ignition switch is at the "LOCK" (OFF)

position.

(2) Start up the personal computer.
(3) Connect special tool MB991827 to special tool MB991824

and the personal computer.

(4) Connect special tool MB991910 to special tool MB991824.
(5) Connect special tool MB991910 to the data link connector.
(6) Turn the power switch of special tool MB991824 to the "ON"

position.
NOTE: When special tool MB991824 is energized, special
tool MB991824 indicator light will be illuminated in a green
color.

(7) Start the M.U.T.-III system on the personal computer.
(8) Turn the ignition switch to the "ON" position.
(9) Check for MFI system diagnostic trouble code (Refer to

GROUP 13A, Diagnostic Function − How to Read and Erase

Diagnostic Trouble Codes

P.13A-9

(10)Turn the ignition switch to the "LOCK" (OFF) position, and

then remove scan tool MB991958 in the reverse order of
installation.

Q: Is the DTC set?

YES : Repair MFI system (Refer to GROUP 13A, Diagnostic

Trouble Code Chart

P.13A-48

). Then go to Step 6.

NO : Go to Step 2.

AC608435

Data link connector

MB991827

MB991824

MB991910

FUEL SUPPLY DIAGNOSIS

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FUEL SUPPLY

13B-4

STEP 2. Check the fuel pressure.
Release residual pressure from the fuel line to prevent fuel
spray (Refer to GROUP 13A, On-vehicle Service − Fuel Pres-

sure Test

P.13A-865

Q: Is the fuel pressure in good condition?

YES : Go to Step 5.
NO : Go to Step 3.

STEP 3. Check for bending, twisting or clogging of the fuel
main pipe and fuel high-pressure hose.
Q: Are the fuel main pipe and fuel high-pressure hose in

good condition?
YES : Go to Step 4.
NO : Repair or replace the fuel main pipe or fuel

high-pressure hose. Then go to Step 6 .

STEP 4. Check the fuel pump operation.
Refer to GROUP 13A, On-vehicle Service − Fuel Pump Opera-

tion Check

P.13A-869

Q: Is the fuel pump module operation in good condition?

YES : Go to Step 5.
NO : Replace the fuel tank pump and gauge assembly

(Refer to

P.13B-6

). Then go to Step 6.

STEP 5. Check the inside of the fuel tank for contamination
and rust.
Remove the fuel tank (Refer to

P.13B-10

Q: Is the fuel tank in good condition?

YES : Go to Step 6.
NO : Replace the fuel filter, and clean the fuel tank and fuel

line. Then go to Step 6 .

STEP 6. Retest the system.
Q: Is the engine malfunction eliminated?

YES : The procedure is complete.
NO : Return to Step 1.

AC709312 AB

Fuel main pipe

Fuel high-pressure hose

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