Page 113 of 558

13-1
FUEL
CONTENTS
MULTIPOINT INJECTION (MPI) 2. . . . . . .
GENERAL 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Outline of Change 2. . . . . . . . . . . . . . . . . . . . . . . . .
SERVICE SPECIFICATIONS 4. . . . . . . . . . . . . .
SEALANT 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SPECIAL TOOLS 5. . . . . . . . . . . . . . . . . . . . . . . .
TROUBLESHOOTING 6. . . . . . . . . . . . . . . . . . . . ON-VEHICLE SERVICE 68. . . . . . . . . . . . . . . .
Fuel Pump Resistor Check 68. . . . . . . . . . . . . . . .
Fuel Pump Relay No.2
Continuity Check 68. . . . . . . . . . . . . . . . . . . . . . . . .
Engine Control Relay and Fuel Pump Relay
Continuity Check 68. . . . . . . . . . . . . . . . . . . . . . . . .
FUEL SUPPLY 69. . . . . . . . . . . . . . . . . . . . .
GENERAL 69. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Outline of Change 69. . . . . . . . . . . . . . . . . . . . . . . .
FUEL TANK 69. . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 114 of 558
MPI – General13-2
MULTIPOINT INJECTION (MPI)
GENERAL
OUTLINE OF CHANGE
The descriptions of the troubleshooting using an MUT-II tester have been added.
The fuel system and its management of EVOLUTION-VI are different from those of EVOLUTION-V
in the following items. Accordingly, the service procedures for these items are described herein. The
service procedures for the remaining item are the same as those for EVOLUTION-V.
Fan motor control
Fuel pump drive control
Fuel pump relay No.2
Fuel pump resistor
Actuator test function of MUT-II (The test of the following items has been made possible.)
a) Item No.36: Secondary air control solenoid valve
b) Item No.37: Air conditioner condenser fan (High)
c) Item No.38: Air conditioner condenser fan (Low)
Page 115 of 558

MPI – General13-3
MPI System Diagram
1 Injector
2 ISC servo
3 Fuel pressure control valve
4 Waste gate solenoid valve
5 Secondary air control solenoid valve
Control relay
Fuel pump relay
A/C relay
Ignition coil
Exhaust temperature warning lamp
Engine warning lamp
Diagnosis output
Alternator G terminal
Fan motor relay
Tachometer
Fuel pump relay No.2 1 Oxygen sensor
2 Air flow sensor
3 Intake air temperature sensor
4 Throttle position sensor
5 Idle switch
6 Camshaft position sensor
7 Crank angle sensor
8 Barometric pressure sensor
9 High temperature sensor
10 Engine coolant temperature sensor
11 Detonation sensor
Power supply voltage
Ignition switch-IG
Ignition switch-ST
Vehicle speed sensor
A/C switch
Power steering fluid pressure switch
Alternator FR signalEngine ECU
1 Oxygen sensor
2 Air flow sensor3
Intake air tem-
perature sensor
4,
5
6 Camshaft position
sensor
7 Crank angle sensor 8 Barometric
pressure sensor
9 High temperature
sensor 10 Coolant temperature sensor
11 Detonation sensor1 Injector 2 ISC servo
3 Fuel pressure
control valve
4 Waste gate
solenoid valve 5 Secondary air
control solenoid
valveCanister
Check valveFrom
fuel
tank
Throttle position
sensor (with a
built-in
idle
switch)
Secondary
air valve
AirTo fuel
tankFuel
pressure
regulatorFrom
fuel
pump
Waste gate
actuator
Catalytic converter
Page 116 of 558
MPI – Service Specifications / Sealant13-4
SERVICE SPECIFICATIONS
ItemsSpecifications
Basic ignition timing BTDC5 ± 3
Basic idle speed rpm850 ± 50
Throttle position sensor adjusting voltage mV400 – 1,000
Throttle position sensor resistance kΩ3.5 – 6.5
ISC servo coil resistance (at 20C) Ω28 – 33
Intake air temperature sensor resistance kΩAt 20C2.3 – 3.0
At 80C0.30 – 0.42
Coolant temperature sensor resistance kΩAt 20C2.1 – 2.7
At 80C0.26 – 0.36
Fuel pressure kPaWhen vacuum hose is connected230
When vacuum hose is disconnected289 – 309
Injector coil resistance Ω2 – 3
Amount of injector fuel leak drop/min1 or less
Oxygen sensor output voltage V0.6 – 1.0
Fuel pressure control valve coil resistance (at 20C) Ω28 – 36
SEALANT
ItemSpecified sealantRemark
Engine coolant temperature sensor
threaded portion3M Nut Locking Part No.4171 or equivalentDrying sealant
Page 117 of 558
MPI – Special Tools13-5
SPECIAL TOOLS
ToolNumberNameUse
MB991502MUT-II sub
assemblyMPI system inspection
MB991348Test harness setMeasurement of voltage during trouble-
shooting
Inspection using an oscilloscope
MB991519Alternator harness
connectorMeasurement of voltage during
troubleshooting
MD998478Test harness
(3-pin, triangle)Measurement of voltage during trouble-
shooting
Inspection using an oscilloscope
Red harness
White harness
MB991223Inspection test
harness set
Pin contact
pressure
inspection
harness
Market tester
contact probe
(for general
connectors)Measurement of terminal voltage
MB991529Diagnostic trouble
code check har-
nessReading of diagnosis codes
MB991709Test harnessMeasurement of voltage during trouble-
shooting
Inspection using an oscilloscope
Page 118 of 558

MPI – Troubleshooting13-6
TROUBLESHOOTING
DIAGNOSIS TROUBLESHOOTING FLOW
Refer to GROUP 00 – How to Use Troubleshooting/Inspection
Service Points.
DIAGNOSIS FUNCTION
ENGINE WARNING LAMP (CHECK ENGINE LAMP)
If an abnormality occurs in any of the following items related
to the Multipoint Fuel Injection (MPI) system, the engine
warning lamp will illuminate.
If the lamp remains illuminated or if the lamp illuminates while
the engine is running, check the diagnosis code output.
Engine warning lamp inspection items
Engine-ECU
Air flow sensor
Intake air temperature sensor
Throttle position sensor
Engine coolant temperature sensor
Crank angle sensor
Camshaft position sensor
Barometric pressure sensor
Detonation sensor
Injector
Ignition coil, power transister unit
METHOD OF READING AND ERASING DIAGNOSIS
CODES
Refer to GROUP 00 – How to Use Troubleshooting/Inspection
Service Points.
INSPECTION USING MUT-II DATA LIST AND
ACTUATOR TESTING
1. Carry out inspection by connecting the MUT-II.
If there is an abnormality, check and repair the chassis
harnesses and components.
2. After repairing, check that the abnormal input and output
have returned to normal as a result of the repairs.
3. Erase the diagnosis code memory.
4. Remove the MUT-II and carry out a road test to confirm
that the problem has disappeared.
Engine warning lamp
(check engine lamp)
Page 119 of 558

MPI – Troubleshooting13-7
FAIL-SAFE FUNCTION REFERENCE TABLE
When the main sensor malfunctions are detected by the diagnosis function, the vehicle is controlled
by means of the pre-set control logic to maintain safe conditions for driving.
Malfunctioning itemControl contents during malfunction
Air flow sensor1. Uses the throttle position sensor signal and engine speed signal (crank angle sensor
signal) to take reading of the basic injector drive time and basic ignition timing from
the pre-set mapping.
2. Fixes the ISC servo in the appointed position so idle control is not performed.
Intake air temperature
sensorControls as if the intake air temperature is 25C.
Throttle position
sensorNo increase in fuel injection amount during acceleration due to the throttle position sensor
signal.
Engine coolant
temperature sensor1. Controls as if the engine coolant temperature is 80C.
(This condition is maintained until the ignition switch is turned off even when the
sensor signal returns normal.)
2. Lets the fan motor (radiator and condenser) run at high speed.
Camshaft position
sensorInjects fuel to all cylinders simultaneously for 4 seconds.
(However, after the ignition switch is turned to ON, the No. 1 cylinder top dead centre is not
detected at all.)
Barometric pressure
sensorControls as if the barometric pressure is 101 kPa.
Detonation sensorSwitches the ignition timing from ignition timing for super petrol to ignition timing for standard
petrol.
Ignition coil, power
transistor unitCuts off the fuel supply to cylinders with an abnormal ignition.
Alternator FR terminalDoes not control the output of the alternator according to an electrical load. (works as a
normal alternator)
Page 120 of 558

MPI – Troubleshooting13-8
3. INSPECTION CHART FOR DIAGNOSIS CODES
Code No.Diagnosis itemReference page
12Air flow sensor system13-8
13Intake air temperature sensor system13-9
14Throttle position sensor system13-9
21Engine coolant temperature sensor system13-10
22Crank angle sensor system13-11
23Camshaft position sensor system13-12
24Vehicle speed sensor system13-13
25Barometric pressure sensor system13-14
31Detonation sensor system13-15
41Injector system13-15
44Ignition coil and power transistor unit system13-16
64Alternator FR terminal system13-17
INSPECTION PROCEDURE FOR DIAGNOSIS CODES
Code No. 12 Air flow sensor systemProbable cause
Range of Check
Engine speed is 500 r/min or more.
Set conditions
Sensor output frequency is 3 Hz or less for 4 seconds.Malfunction of the air flow sensor
Improper connector contact, open or short-circuited
harness wire of the air flow sensor
Malfunction of the engine-ECU
Measure at the air flow sensor con-
nector A-25.
Connect the connector. (Use
the test harness: MB991709)
1. Voltage between 3 and earth
(Engine: Idling)
OK:2.2–3.2 V
2. Voltage between 7 and earth
OK:0–1 V (Engine: idling)
6–9 V (2,000 r/min)
OK
Replace the engine-ECU.1. NG
Check the air flow sensor circuit.
(Refer to P.13-55, INSPECTION
PROCEDURE 48.)
2. NG
Measure at the engine-ECU con-
nector B-59.
Connect the connector.
Voltage between 19 and earth
(Ignition switch: ON)
OK:6–9 V
OK
Check the following connector:
B-59
OK
Check trouble symptom.
NG
Replace the engine-ECU.NG
Check the following connector:
A-25NG
Repair
OK
Check trouble symptom.
NG
NG
Repair
Replace the air flow sensor.