MPI – Troubleshooting13-7
1-3 ERASING DIAGNOSIS CODES
(1) Turn the ignition switch to OFF.
(2) After disconnecting the battery cable from the battery (–) terminal for 10 seconds or more, reconnect
the cable.
(3) After the engine has warmed up, run it at idle for about 15 minutes.
1-4 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 sensor (AFS)(1) 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
sensor (TPS)No increase in fuel injection amount during acceleration due to the throttle position sensor
signal.
Engine coolant
temperature sensorControls 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.)
Camshaft position
sensor(1) Injects 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.)
(2) Lets the fan motor (radiator and condensor) run at high speed.
Barometric pressure
sensorControls as if the barometric pressure is 101 kPa {760 mmHg}.
Detonation sensorSwitches the ignition timing from ignition timing for super petrol to ignition timing for standard
petrol.
Ignition coil, power
transistorCuts 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)
Misfire
(Evolution-V only)Cuts off the fuel to the misfiring cylinder if a misfire that could damage the catalyst is detected.
MPI – Troubleshooting13-8
2. INSPECTION CHART FOR DIAGNOSIS CODES
Code No.Diagnosis itemReference page
12Air flow sensor (AFS) system13-8
13Intake air temperature sensor system13-9
14Throttle position sensor (TPS) system13-9
21Engine coolant temperature sensor system13-10
22Crank angle sensor system13-11
23Camshaft position sensor system13-11
24Vehicle speed sensor system13-12
25Barometric pressure sensor system13-13
31Detonation sensor system13-14
41Injector system13-14
44Ignition coil and power transistor unit system13-15
64Alternator FR terminal system13-16
3. INSPECTION PROCEDURE FOR DIAGNOSIS CODES
Code No. 12 Air flow sensor (AFS) 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 circuit 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.
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.
MPI – Troubleshooting13-11
Code No. 22 Crank angle sensor systemProbable cause
Range of Check
Engine is cranking.
Set conditions
Sensor output voltage does not change for 4 seconds (no pulse signal input.)Malfunction of the crank angle sensor
Improper connector contact, open circuit or
short-circuited harness wire of the crank angle sensor
Malfunction of the engine-ECU
Measure at the crank angle sensor connector A-51.
Connect the connector. (Use the test harness: MD998478.)
Voltage between 2 (black clip) and earth (Engine: cranking)
OK:0.4–4.0 V
Voltage between 2 (black clip) and earth (Engine: idling)
OK:1.5–2.5 V
NGOKReplace the engine-ECU.
Measure at the crank angle sensor connector A-51.
Disconnect the connector, and measure at the harness side.
1. Voltage between 3 and earth (Ignition switch: ON)
OK:System voltage
2. Voltage between 2 and earth (Ignition switch: ON)
OK:4.8–5.2 V
3. Continuity between 1 and earth
OK:Continuity
OK
Check the following con-
nector: A-51NG
Repair
OK
Check trouble symptom.
NG
Replace the crank angle sensor.1. NG
Check the harness wire between the crank angle sensor and the
control relay connector, and repair if necessary.
2. NGCheck the following con-
nector: B-62NG
Repair
OK3. NG
Check trouble symptom.
NG
Check the harness wire
between the engine-ECU and
the crank angle sensor
connector.NG
Repair
OK
Replace the engine-ECU.
Check the harness wire between the crank angle sensor and the
earth, and repair if necessary.
Code No. 23 Camshaft position sensor systemProbable cause
Range of Check
Ignition switch: ON
Engine speed is approx. 50 r/min or more.
Set conditions
Sensor output voltage does not change for 4 seconds (no pulse signal input.)Malfunction of the camshaft position sensor
Improper connector contact, open circuit or
short-circuited harness wire of the camshaft position
sensor circuit
Malfunction of the engine-ECU
Measure at the camshaft position sensor connector A-97.
Connect the connector.
Voltage between 2 and earth (Engine: cranking)
OK:0.4–3.0 V
Voltage between 2 and earth (Engine: idling)
OK:0.5–2.0 VOKReplace the engine-ECU.
NG
Measure at the camshaft position sensor connector A-97.
Disconnect the connector, and measure at the harness side.
1. Voltage between 3 and earth (Ignition switch: ON)
OK:System voltage
2. Voltage between 2 and earth (Ignition switch: ON)
OK:4.8–5.2 V
3. Continuity between 1 and earth
OK:Continuity1. NGCheck the harness wire between the camshaft position sensor
and the control relay connector, and repair if necessary.
2. NGCheck the following con-
nector: B-62NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire
between the engine-ECU and
the camshaft position sensor
connector.NG
Repair
OK
Replace the engine-ECU. 3. NG
Check the harness wire between the camshaft position sensor
and the earth, and repair if necessary.
OK
Check the following con-
nector: A-97NG
Repair
OK
Check trouble symptom.
NG
Replace the camshaft position sensor.
MPI – Troubleshooting13-24
Terminal
No.Normal condition Check condition (Engine condition) Check item
72Intake air temperature
sensorIgnition switch: ONWhen intake air tempera-
ture is 0C3.2 – 3.8 V
When intake air tempera-
ture is 20C2.3 – 2.9 V
When intake air tempera-
ture is 40C1.5 – 2.1 V
When intake air tempera-
ture is 80C0.4 – 1.0 V
76Oxygen sensorEngine: Running at 2,000 r/min after having been
warmed up (Check using a digital type voltmeter)0 ↔ 0.8 V
(Changes repeatedly)
80Backup power supplyIgnition switch: OFFBattery voltage
81Sensor impressed
voltageIgnition switch: ON4.5 – 5.5 V
82Ignition switch-IGIgnition switch: ONBattery voltage
83Engine coolant
temperature sensorIgnition switch: ONWhen engine coolant
temperature is 0C3.2 – 3.8 V
When engine coolant
temperature is 20C2.3 – 2.9 V
When engine coolant
temperature is 40C1.3 – 1.9 V
When engine coolant
temperature is 80C0.3 – 0.9 V
84Throttle position sensorIgnition switch: ONSet throttle valve to idle
position0.3 – 1.0 V
Fully open throttle valve4.5 – 5.5 V
85Barometric pressure
sensor
Ignition switch: ONWhen altitude is 0 m3.7 – 4.3 V
sensor
When altitude is 1,200 m3.2 – 3.8 V
86Vehicle speed sensorIgnition switch: ON
Move the vehicle slowly forward0 ↔ 5 V
(Changes repeatedly)
87Idle position switchIgnition switch: ONSet throttle valve to idle
position0 – 1 V
Slightly open throttle
valve4 V or more
88Camshaft position
sensor
Engine: Cranking0.4 – 3.0 V
sensor
Engine: Idle speed0.5 – 2.0 V
89Crank angle sensorEngine: Cranking0.4 – 4.0 V
Engine: Idle speed1.5 – 2.5 V
90Air flow sensorEngine: Idle speed2.2 – 3.2 V
Engine speed: 2,500 r/min
MPI – Troubleshooting13-26
7. INSPECTION PROCEDURE USING
OSCILLOSCOPE
7-1 AIR FLOW SENSOR (AFS)
Observing waveforms displayed on the oscilloscope allows
you to visually identify possible unusual disturbances in
waveform that could temporarily occur in the air flow sensor
output.
(1) Disconnect the air flow sensor connector and connect
the special tool (Test Harness: MB991709) to it. (Ensure
that all terminals are connected.)
(2) Connect the oscilloscope probe to terminal no. 3 of air
flow sensor connector.
NOTE
If the engine ECU connector is used, connect the
oscilloscope probe to terminal no. 90.
(3) Perform the same steps from here on as with the 4G9
engine.
7-2 CAMSHAFT POSITION SENSOR AND CRANK
ANGLE SENSOR
Perform the same steps as with the conventional 4G9 engine
for the inspection.
7-3 INJECTOR
Observing waveforms displayed on the oscilloscope allows
you to visually check the conditions of injector drive signals
actually output from the engine ECU.
Injector Control Signal (Oscilloscope 1)
(1) Disconnect the injector connector and connect the special
tool (Test Harness: MB991348) to the circuit. (Ensure
that the terminals on both the power supply and engine
ECU sides are connected.)
(2) Connect the oscilloscope probe to terminal no. 2 of injector
connector.
NOTE
If the engine ECU connector is used for the measurement,
take measurements at each of the following terminals.
Connect the oscilloscope probe to terminal no. 1 when
the waveform is observed with no. 1 cylinder, to terminal
no. 14 when the waveform is observed with no. 2 cylinder,
to terminal no. 2 when the waveform is observed with
no. 3 cylinder, and to terminal no. 15 when the waveform
is observed with no. 4 cylinder.
Oscilloscope
Oscilloscope
MPI – On-vehicle Service13-31
5. MPI SYSTEM COMPONENTS LAYOUT
NameSymbolNameSymbol
A/C switchQExhaust temperature warning lampS
A/C relayHFuel pressure control valveA
Air flow sensor (with a built-in intake air temperaturesensor and barometric pressure sensor)FIgnition coil and power transistor unitLsensor and barometric pressure sensor)InjectorB
Camshaft position sensorMISC servoD
Control relay and fuel pump relayPOxygen sensorK
Coolant temperature sensorEPower steering fluid pressure switchI
Crank angle sensorJSecondary air control solenoid valveN
Detonation sensorCThrottle position sensor (with a built-in idle switch)D
Diagnosis connectorR
Engine ECUOVehicle speed sensorT
Engine warning lampSWastegate solenoid valveG
16-1
ENGINE
ELECTRICAL
CONTENTS
CHARGING SYSTEM 2. . . . . . . . . . . . . . . .
ALTERNATOR 2. . . . . . . . . . . . . . . . . . . . . . . . . . .
IGNITION SYSTEM 4. . . . . . . . . . . . . . . . . .
ON-VEHICLE SERVICE 4. . . . . . . . . . . . . . . . . . .
1. Ignition Coil with Built-in Power Transistor
Check 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2. Spark Plug Check, Cleaning, and
Replacement 4. . . . . . . . . . . . . . . . . . . . . . . . . .
CAMSHAFT POSITION SENSOR AND
CRANK ANGLE SENSOR
5 . . . . . . . . . . . . .
ENGINE ELECTRICAL – Ignition System16-5
CAMSHAFT POSITION SENSOR AND CRANK ANGLE SENSOR
REMOVAL AND INSTALLATION
Pre-removal and Post-installation Operation
Timing Belt Removal and Installation
(Refer to GROUP 11.)
Unit: Nm {kgfm}
49 {5.0}
5
9 {0.9}9 {0.9}
9 {0.9} 39 {4.0} 3 {0.3}
2
3
41
Removal steps
1. Camshaft position sensor
2. Center cover
A3. Power steering oil pump4. Power steering oil pump bracket
5. Crank angle sensor
REMOVAL SERVICE POINT
APOWER STEERING OIL PUMP REMOVAL
Remove the power steering oil pump with hose from the power
steering oil pump bracket.
NOTE
String up the oil pump which has been removed onto a location
that does not hamper removal and installation of the power
steering oil pump bracket.