MPI -General Information13A-5
MULTI-POINT FUEL INJECTION SYSTEM DIAGRAM
L1 Oxygen sensor (front)
L2 Oxygen sensor (rear)
L3 Air flow sensor
L4 Intake air temperature sensor
L5 Throttle position sensor
L6 Camshaft position sensor
L7 Crank angle sensor
L8 Barometric pressure sensor
L9 Engine coolant temperature sensor
L10 Detonation sensor
Engine-ECU
l1 Injector
l2 Idle speed control servo
l3 Fuel pressure control solenoid valve
l4 Waste gate solenoid valve
l5 EGR control solenoid valve
l6 Purge control solenoid valve
l7 Secondary air control solenoid valve
DPower supply
DIgnition switch IG
DIgnition switch ST
DVehicle speed sensor
DA/C switch
DA/C load signal
DTachometer
DPower steering fluid pressure switch
DAlternator FR terminal
DDiagnosis control terminal
DIntercooler water spray switch (automatic)
DIntercooler water spray switch (manual)DEngine control relay
DFuel pump relay 2, 3
DA/C relay
DIgnition coil
DFan controller
DCondenser fan relay (HI)
DCondenser fan relay (LOW)
DEngine warning lamp
DDiagnosis output
DAlternator G terminal
DIntercooler water spray relay
DIntercooler water spray lamp
L1 Oxygen
sensor
(front)
L4 Intake air
temperature
sensorL5 Throttle
position
sensor
L6 Camshaft
position sensorl1 Injector l2 Idle
speed
control
servo
l6 Purge
control
solenoid
valve
Three-way
catalytic converter Canister
Air
inletVacuum
tank
Fuel
pressure
reguratorFrom
fuel tank
To fuel tank
PCV valveFrom
fuel pump
Waste gate
actuatorL2 Oxygen sensor (rear) Check
valveBy-pass
valve
l5 EGR control
solenoid valve
l4 Waste gate
solenoid valve L8 Barometric
pressure
sensor
L3 Air flow
sensorl7 Secondary
air control
solenoid
valve
Secondary
air valvel3 Fuel pressure
control
solenoid valve
EGR
valve
L9 Engine coolant
temperature sensor
L7 Crank angle sensor
L10 Detonation sensor
MPI -Troubleshooting13A-13
DIAGNOSTIC TROUBLE CODE INSPECTION PROCEDURE
Code No. P0100 Air flow sensor systemProbable cause
Inspection Range
DEngine speed: More than 500 r/min
Evaluation Conditions
DThe sensor output frequency is less than 3 Hz for 4 seconds.DAir flow sensor malfunction
DAir flow sensor circuit disconnection, short-circuit,
or connector contact defect
DEngine-ECU malfunction
OK
Intermittent malfunction
(Refer to GROUP 00 - Points to Note
for Intermittent Malfunctions.)
OK
MUT-IIData list
DNo. 12 Air flow sensor
(Refer to P.13A-102.)NGReplace engine-ECU.
OK
To the next pageOK
Check the harness between the air
flow sensor and engine-ECU.
DCheck for ground wire
disconnection and damage.NG
Repair
(3) NGCheck the following connector:
C-115NG
Repair
OK
Check the harness between the air
flow sensor and engine control relay.
DCheck for power cable
disconnection and short-circuit.
(2) NGCheck the following connector:
B-11XNG
OK
Intermittent malfunction
(Refer to GROUP 00 - Points to Note
for Intermittent Malfunctions.)
OK
MUT-IIData list
DNo. 12 Air flow sensor
(Refer to P.13A-102.)NGReplace engine-ECU.
OK
Check the harness between the air
flow sensor and engine-ECU.
DCheck for short-circuit of the
output wire.NG
Repair
NG
Check the following connector:
C-115NG
Repair
OK
Check and repair the harness between
the air flow sensor and engine-ECU.
DCheck for disconnection of the
output wire.NG
Repair
OK
Measure at the B-31 air flow sensor
connector.
DDisconnect the connector to
measure at the harness side
(1) Voltage between terminal No. 3
and earth
(Ignition switch: ON)
OK:4.9 - 5.1 V
(2) Voltage between terminal No. 4
and earth
(Ignition switch: ON)
OK:System voltage
(3) Resistance between terminal No.
5 and earth
OK:Less than 2Ω(1) NGMeasure at the C-115 engine-ECU
connector.
DMeasure the voltage of the
engine-ECU terminal.
DIgnition switch: ON
DVoltage between terminal No. 90
and earth.
OK:4.9 - 5.1 VOKCheck the following connector:
C-115
NG
Check the following connector:
B-31NG
Repair
MUT-IIData list
DNo. 12 Air flow sensor
(Refer to P.13A-102.)OKIntermittent malfunction
(Refer to GROUP 00 - Points to Note
for Intermittent Malfunctions.)
Repair
MPI -Troubleshooting13A-14
OK
Check the harness between the air
flow sensor and engine-ECU.
DCheck for damage of the output
wire.
DCheck for damage of the earth
wire.NG
OK
Check the harness between the air
flow sensor and engine control relay.
DCheck for damage of the power
cable.Repair NG
NG
Check the following connectors:
B-11X, C-115Repair OK
Check the trouble symptom.End
OK
Intermittent malfunction
(Refer to GROUP 00 - Points to Note
for Intermittent Malfunctions.)
OK
MUT-IIData list
DNo. 12 Air flow sensor
(Refer to P.13A-102.)NGReplace engine-ECU.
Replace the air flow sensor.
OK
Intermittent malfunction
(Refer to GROUP 00 - Points to Note
for Intermittent Malfunctions.)
OK
Measure the output waveform at the
B-31 air flow sensor connector (using
an analyzer).
DUsing the test harness
(MB991709), connect the
connector, and measure at the
pickup harness.
DEngine: Idle
DVoltage between terminal No. 3
and earth.
OK:Output the waveform as
shown on P.13A-112 (in-
spection procedure by ana-
lyzer), and check that there
is noise in the output wave-
form.NG
OK
MUT-IIData list
DNo. 12 Air flow sensor
(Refer to P.13A-102.)NGReplace engine-ECU.
OK
Check the harness between air flow
sensor and engine-ECU.
DCheck for disconnection and
damage of the reset signal wire.NG
Repair
OK
Measure at the B-31 air flow sensor
connector.
DUsing the test harness
(MB991709), connect the
connector, and measure at the
pickup harness.
DVoltage between terminal No. 7
and earth.
OK:Engine: idle
0-1V
Engine: 3,000 r/min
6-9VNGCheck the following connector:
C-126NGRepair
OK
Replace the air flow sensor.
OK
Check the harness between the air
flow sensor and engine-ECU.
DCheck for short-circuit of the
reset signal wire.NG
Repair
OK
Measure at the B-31 air flow sensor
connector.
DUsing the test harness
(MB991709), connect the
connector, and measure at the
pickup.
DIgnition switch: ON
DVoltage between terminal No. 7
and earth.
OK:7-8VNGCheck the following connector:
C-126NGRepair
From the previous page
MPI -Troubleshooting13A-26
Code No. P0135 Oxygen sensor heater (front) systemProbable cause
Inspection Range
DThe engine coolant temperature is approximately more than 20_C.
DThe oxygen sensor heater (front) is ON.
DThe engine speed is more than 50 r/min.
DA/C relay: OFF, radiator fan: OFF
DThe battery voltage is 11 - 16 V.
Evaluation Conditions
DThe oxygen sensor heater (front) current is less than 0.2 A or more than 3.5
A for 4 seconds.DOxygen sensor heater (front) malfunction
DOxygen sensor heater (front) circuit disconnection,
short-circuit, or connector contact defect
DEngine-ECU malfunction
OK
Intermittent malfunction
(Refer to GROUP 00 - Points to Note
for Intermittent Malfunctions.)
OK
Check the trouble symptom.NGReplace the engine-ECU.
OK
Check the harness between the
oxygen sensor (front) and
engine-ECU.
DCheck for damage of the earth
wire.NG
repair
OK
Check the harness between the
oxygen sensor (front) and engine
control relay.
DCheck for damage of the power
cable.NG
Repair
OK
Check the following connector:
C-118NG
Repair
OK
Replace the engine-ECU.NG
OK
Check the harness between the
oxygen sensor (front) and
engine-ECU.
DCheck for disconnection and
short-circuit of the earth wire.Repair
OK
Measure at the C-118 engine-ECU
connector.
DMeasure the engine-ECU terminal
voltage.
DIgnition switch: ON
DVoltage between terminal No. 60
and earth.
OK:System voltageNGCheck the following connector:
C-118NG
Repair
OK
Check and repair the harness between
the oxygen sensor (front) and engine
control relay.
DCheck the power cable for
disconnection and short-circuit.
OK
Measure at the B-34 oxygen sensor
(front) connector.
DDisconnect the connector, and
measure at the harness.
DIgnition switch: ON
DVoltage between terminal No. 1
and earth
OK:System voltageNGCheck the following connector:
B-11XNG
Repair
OK
Measure at the B-34 oxygen sensor
(front) connector.
DDisconnect the connector, and
measure at the sensor.
DResistance between terminal No.
1 and terminal No. 3.
OK:4.5 - 8.0ΩNGReplace the oxygen sensor (front).
Check the following connector:
B-34NG
Repair
MPI -Troubleshooting13A-29
Code No. P0141 Oxygen sensor heater (rear) systemProbable cause
Inspection Range
DThe engine coolant water temperature is approximately more than 20_C.
DThe oxygen sensor heater (rear) is ON.
DThe engine speed is more than 50 r/min.
DA/C relay: OFF, radiator fan: OFF
DThe battery voltage is 11 - 16 V.
Evaluation Conditions
DThe oxygen sensor heater (rear) current is less than 0.2 A or more than 3.5
A for 4 seconds.DOxygen sensor heater (rear) malfunction
DOxygen sensor heater (rear) circuit disconnection,
short-circuit, or connector contact defect
DEngine-ECU malfunction
OK
Intermittent malfunction
(Refer to GROUP 00 - Points to Note
for Intermittent Malfunctions.)
OK
Check the trouble symptom.NGReplace the engine-ECU.
OK
Check the harness between the
oxygen sensor (rear) and engine-ECU.
DCheck for damage of the earth
wire.NG
Repair
OK
Check the harness between the
oxygen sensor (rear) and engine
control relay.
DCheck for damage of the power
cable.NG
Repair
OK
Check the following connector:
B-11X, C-108NG
Repair
OK
Replace the engine-ECU.NG
OK
Check the harness between the
oxygen sensor (rear) and engine-ECU.
DCheck for disconnection and
short-circuit of the earth wire.Repair
OK
Measure at the C-118 engine-ECU
connector.
DMeasure the engine-ECU terminal
voltage.
DIgnition switch: ON
DVoltage between terminal No. 54
and earth.
OK:System voltageNGCheck the following connector:
C-118NG
Repair
OK
Check and repair the harness between
the oxygen sensor (rear) and engine
control relay.
DCheck the power cable for
disconnection and short-circuit.
OK
Measure at the D-22 oxygen sensor
(rear) connector.
DDisconnect the connector, and
measure at the harness.
DIgnition switch: ON
DVoltage between terminal No. 3
and earth
OK:System voltageNGCheck the following connector:
B-11XNG
Repair
OK
Measure at the D-22 oxygen sensor
(rear) connector.
DDisconnect the connector, and
measure at the sensor.
DResistance between terminal No.
3 and terminal No. 4.
OK:11 - 1 8ΩNGReplace the oxygen sensor (rear).
Check the following connector:
D-22NG
Repair
MPI -Troubleshooting13A-30
Code No. P0201 No. 1 injector systemProbable cause
Inspection Range
DThe engine speed is 50 - 1,000 r/min.
DThe throttle position sensor output voltage is 1.15 V or less.
DMUT-IIforced drive (actuator test) is not being carried out.
Evaluation Conditions
DSurge voltage at injector coil is not detected for 2 seconds.DNo. 1 injector malfunction
DNo. 1 injector circuit disconnection, short-circuit, or
connector contact defect
DEngine-ECU malfunction
OKIntermittent malfunction
(Refer to GROUP 00 - Points to Note
for Intermittent Malfunctions.)
OK
Measure the signal waveform at the
C-126 engine-ECU connector (using
an analyzer).
DEngine: Idling
DVoltage between terminal No. 1 and
earth
OK:The waveform shown on
P.13A-119 (Inspection Proce-
dure Using Analyzer) should
be output.NGReplace the engine-ECU.
OK
Check the harness between the No. 1
injector and engine-ECU.
DCheck for disconnection,
short-circuit and damage of the
output cable.NG
Repair
OK
Check the following connector:
C-126NG
Repair
OK
Check the harness between the resis-
tor (for injector) and engine control
relay.
DCheck for damage of the power
cable.NG
Repair
OK
Check the harness between the No. 1
injector and resistor (for injector).
DCheck for damage of the power
cable.NG
Repair
OK
Check and repair the harness between
the resistor (for injector) and engine
control relay.
DCheck for disconnection and
short-circuit of the power cable.NG
OK
Check the harness between the No. 1
injector and resistor (for injector).
DCheck for disconnection and
short-circuit of the power cable.Repair
OK
Check the resistor. (Refer to
P.13A-138.)
OK
Measure at the B-27 No. 1 injector
connector.
DDisconnect the connector to
measure at the harness side.
DIgnition switch: ON
DVoltage between terminal No. 1 and
earth
OK:System voltageNGCheck the following connectors:
B-11X, B-138, C-108NG
Repair
OK
Measure at the B-27 No. 1 injector
connector.
DDisconnect the connector to
measure at the injector side.
DResistance between terminal No. 1
and terminal No. 2
OK:2-3ΩNGReplace the No. 1 injector.
NG
Check the following connector:
B-27NG
Repair
MUT-IIActuator test
DNo. 01: No. 1 injector
OK:The idling state changes.OKIntermittent malfunction
(Refer to GROUP 00 - Points to Note
for Intermittent Malfunctions.)
MPI -Troubleshooting13A-31
Code No. P0202 No. 2 injector systemProbable cause
Inspection Range
DThe engine speed is 50 - 1,000 r/min.
DThe throttle position sensor output voltage is 1.15 V or less.
DMUT-IIforced drive (actuator test) is not being carried out.
Evaluation Conditions
DSurge voltage at injector coil is not detected for 2 seconds.DNo. 2 injector malfunction
DNo. 2 injector circuit disconnection, short-circuit, or
connector contact defect
DEngine-ECU malfunction
OKIntermittent malfunction
(Refer to GROUP 00 - Points to Note
for Intermittent Malfunctions.)
OK
Measure the signal waveform at the
C-126 engine-ECU connector (using
an analyzer).
DEngine: Idling
DVoltage between terminal No. 1 and
earth
OK:The waveform shown on
P.13A-119 (Inspection Proce-
dure Using Analyzer) should
be output.NGReplace the engine-ECU.
OK
Check the harness between the No. 2
injector and engine-ECU.
DCheck for disconnection,
short-circuit and damage of the
output cable.NG
Repair
OK
Check the following connector:
C-126NG
Repair
OK
Check the harness between the resis-
tor (for injector) and engine control
relay.
DCheck for damage of the power
cable.NG
Repair
OK
Check and repair the harness between
the resistor (for injector) and engine
control relay.
DCheck for disconnection and
short-circuit of the power cable.NG
OK
Check the harness between the No. 2
injector and resistor (for injector).
DCheck for disconnection and
short-circuit of the power cable.Repair NG
OK
Check the resistor. (Refer to
P.13A-138.)Repair
OK
Check the harness between the No. 2
injector and resistor (for injector).
DCheck for damage of the power
cable.NG
Repair
OK
Measure at the B-26 No. 2 injector
connector.
DDisconnect the connector to
measure at the harness side.
DIgnition switch: ON
DVoltage between terminal No. 1 and
earth
OK:System voltageNGCheck the following connectors:
B-11X, B-138, C-108NG
Repair
OK
Measure at the B-26 No. 2 injector
connector.
DDisconnect the connector to
measure at the injector side.
DResistance between terminal No. 1
and terminal No. 2
OK:2-3ΩNGReplace the No. 2 injector.
NG
Check the following connector:
B-26NG
Repair
MUT-IIActuator test
DNo. 02: No. 2 injector
OK:The idling state changes.OKIntermittent malfunction
(Refer to GROUP 00 - Points to Note
for Intermittent Malfunctions.)
MPI -Troubleshooting13A-32
Code No. P0203 No. 3 injector systemProbable cause
Inspection Range
DThe engine speed is 50 - 1,000 r/min.
DThe throttle position sensor output voltage is 1.15 V or less.
DMUT-IIforced drive (actuator test) is not being carried out.
Evaluation Conditions
DSurge voltage at injector coil is not detected for 2 seconds.DNo. 3 injector malfunction
DNo. 3 injector circuit disconnection, short-circuit, or
connector contact defect
DEngine-ECU malfunction
OKIntermittent malfunction
(Refer to GROUP 00 - Points to Note
for Intermittent Malfunctions.)
OK
Measure the signal waveform at the
C-126 engine-ECU connector (using
an analyzer).
DEngine: Idling
DVoltage between terminal No. 1 and
earth
OK:The waveform shown on
P.13A-119 (Inspection Proce-
dure Using Analyzer) should
be output.NGReplace the engine-ECU.
OK
Check the harness between the No. 3
injector and engine-ECU.
DCheck for disconnection,
short-circuit and damage of the
output cable.NG
Repair
OK
Check the following connector:
C-126NG
Repair
OK
Check the harness between the resis-
tor (for injector) and engine control
relay.
DCheck for damage of the power
cable.NG
Repair
OK
Check and repair the harness between
the resistor (for injector) and engine
control relay.
DCheck for disconnection and
short-circuit of the power cable.NG
OK
Check the harness between the No. 3
injector and resistor (for injector).
DCheck for disconnection and
short-circuit of the power cable.Repair NG
OK
Check the resistor. (Refer to
P.13A-138.)Repair
OK
Check the harness between the No. 3
injector and resistor (for injector).
DCheck for damage of the power
cable.NG
Repair
OK
Measure at the B-25 No. 3 injector
connector.
DDisconnect the connector to
measure at the harness side.
DIgnition switch: ON
DVoltage between terminal No. 1 and
earth
OK:System voltageNGCheck the following connectors:
B-11X, B-138, C-108NG
Repair
OK
Measure at the B-25 No. 3 injector
connector.
DDisconnect the connector to
measure at the injector side.
DResistance between terminal No. 1
and terminal No. 2
OK:2-3ΩNGReplace the No. 3 injector.
NG
Check the following connector:
B-25NG
Repair
MUT-IIActuator test
DNo. 03: No. 3 injector
OK:The idling state changes.OKIntermittent malfunction
(Refer to GROUP 00 - Points to Note
for Intermittent Malfunctions.)