
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
EC-131
< SERVICE INFORMATION >
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6.CHECK FUEL PRESSURE
Check fuel pressure. (Refer to EC-78, "
Fuel Pressure Check".)
OK or NG
OK >> GO TO 9.
NG (Fuel pressure is too high)>>Replace fuel pressure regulator, refer to EC-78, "
Fuel Pressure Check". GO
TO 8.
NG (Fuel pressure is too low)>>GO TO 7.
7.DETECT MALFUNCTIONING PART
1. Check the following.
- Clogged and bent fuel hose and fuel tube
- Clogged fuel filter
- Fuel pump and its circuit (Refer to EC-526
.)
2. If NG, repair or replace the malfunctioning part. (Refer to EC-78, "
Fuel Pressure Check".)
If OK, replace fuel pressure regulator.
>> GO TO 8.
8.CHECK “A/F ALPHA-B1”
1. Start engine.
2. Select “A/F ALPHA-B1” in “DATA MONITOR (SPEC)” mode, and make sure that the indication is within
the SP value.
OK or NG
OK >>INSPECTION END
NG >> GO TO 9.
9.PERFORM POWER BALANCE TEST
1. Perform “POWER BALANCE” in “ACTIVE TEST” mode.
2. Make sure that the each cylinder produces a momentary engine
speed drop.
OK or NG
OK >> GO TO 12.
NG >> GO TO 10.
10.DETECT MALFUNCTIONING PART
1. Check the following.
- Ignition coil and its circuit (Refer to EC-531
.)
- Fuel injector and its circuit (Refer to EC-521
.)
- Intake air leakage
- Low compression pressure (Refer to EM-62, "
On-Vehicle Service".)
2. If NG, repair or replace the malfunctioning part.
If OK, replace fuel injector. (It may be caused by leakage from fuel injector or clogging.)
>> GO TO 11.
11 .CHECK “A/F ALPHA-B1”
1. Start engine.
2. Select “A/F ALPHA-B1” in “DATA MONITOR (SPEC)” mode, and make sure that the indication is within
the SP value.
OK or NG
OK >>INSPECTION END
NG >> GO TO 12.
PBIB0133E

DTC P0075 IVT CONTROL SOLENOID VALVE
EC-165
< SERVICE INFORMATION >
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• Harness connectors E8, F8
• Harness for open or short between intake valve timing control solenoid valve and IPDM E/R
>> Repair or replace harness or connectors.
3.CHECK INTAKE VALVE TIMING CONTROL SOLENOID VALVE OUTPUT SIGNAL CIRCUIT FOR OPEN
AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 73 and intake valve timing control solenoid valve termi-
nal 2. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK INTAKE VALVE TIMING CONTROL SOLENOID VALVE
Refer to EC-165, "
Component Inspection".
OK or NG
OK >> GO TO 5.
NG >> Replace intake valve timing control solenoid valve.
5.CHECK INTERMITTENT INCIDENT
Refer to EC-136
.
>>INSPECTION END
Component InspectionINFOID:0000000001702646
INTAKE VALVE TIMING CONTROL SOLENOID VALVE
1. Disconnect intake valve timing control solenoid valve harness connector.
2. Check resistance between intake valve timing control solenoid
valve as follows.
If NG, replace intake valve timing control solenoid valve.
If OK, go to next step.
3. Remove intake valve timing control solenoid valve.
4. Provide 12V DC between intake valve timing control solenoid
valve terminals and then interrupt it. Make sure that the plunger
moves as shown in the figure.
CAUTION:
Do not apply 12V DC continuously for 5 seconds or more.
Doing so may result in damage to the coil in intake valve
timing control solenoid valve.
If NG, replace intake valve timing control solenoid valve.
NOTE:
Always replace O-ring when intake valve timing control
solenoid valve is removed.Continuity should exist.
Terminal Resistance
1 and 2 6.7 - 7.7Ω [at 20°C (68°F)]
1 or 2 and ground∞Ω
(Continuity should not exist.)
PBIB0574E
PBIB2388E

EC-262
< SERVICE INFORMATION >
DTC P0171 FUEL INJECTION SYSTEM FUNCTION
1. Install all removed parts.
2. Start engine and warm it up to normal operating temperature.
3. Check mass air flow sensor signal in Service $01 with GST.
OK or NG
OK >> GO TO 7.
NG >> Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or
ground. Refer to EC-167
.
7.CHECK FUNCTION OF FUEL INJECTORS
With CONSULT-II
1. Let engine idle.
2. Perform “POWER BALANCE” in “ACTIVE TEST” mode with
CONSULT-II.
3. Make sure that each circuit produces a momentary engine
speed drop.
Without CONSULT-II
1. Let engine idle.
2. Listen to each fuel injector operating sound.
OK or NG
OK >> GO TO 8.
NG >> Perform trouble diagnosis for EC-521
.
8.CHECK FUEL INJECTOR
1. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
2. Turn ignition switch OFF.
3. Reconnect all harness connectors disconnected.
4. Remove fuel tube assembly. Refer to EM-33
.
Keep fuel hose and all fuel injector connected to fuel tube.
The fuel injector harness connectors should remain connected.
5. Disconnect all ignition coil harness connectors.
6. Prepare pans or saucers under each fuel injector.at idling : 1.0 - 4.0 g·m/sec
at 2,500 rpm : 2.0 - 10.0 g·m/sec
PBIB0133E
Clicking noise should be heard.
PBIB3332E

DTC P0172 FUEL INJECTION SYSTEM FUNCTION
EC-269
< SERVICE INFORMATION >
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OK >> GO TO 7.
NG >> Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or
ground. Refer to EC-167
.
7.CHECK FUNCTION OF FUEL INJECTORS
With CONSULT-II
1. Let engine idle.
2. Perform “POWER BALANCE” in “ACTIVE TEST” mode with
CONSULT-II.
3. Make sure that each circuit produces a momentary engine
speed drop.
Without CONSULT-II
1. Let engine idle.
2. Listen to each fuel injector operating sound.
OK or NG
OK >> GO TO 8.
NG >> Perform trouble diagnosis for EC-521
.
8.CHECK FUEL INJECTOR
1. Remove fuel injector assembly. Refer to EM-33
.
Keep fuel hose and all fuel injector connected to fuel tube.
2. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
3. Reconnect all harness connectors disconnected.
4. Disconnect all ignition coil harness connectors.
5. Prepare pans or saucers under each fuel injector.
6. Crank engine for about 3 seconds.
Make sure fuel does not drip from fuel injector.
OK or NG
OK (Does not drip.)>>GO TO 9.
NG (Drips.)>>Replace the fuel injectors from which fuel is dripping. Always replace O-ring with new one.
9.CHECK INTERMITTENT INCIDENT
Refer to EC-136
.
>>INSPECTION END at idling : 1.0 - 4.0 g·m/sec
at 2,500 rpm : 2.0 - 10.0 g·m/sec
PBIB0133E
Clicking noise should be heard.
PBIB3332E

EC-286
< SERVICE INFORMATION >
DTC P0300 - P0304 MULTIPLE CYLINDER MISFIRE, NO. 1 - 4 CYLINDER MIS-
FIRE
1. Perform “POWER BALANCE” in “ACTIVE TEST” mode.
2. Is there any cylinder which does not produce a momentary
engine speed drop?
Without CONSULT-II
When disconnecting each fuel injector (1) harness connector one at
a time, is there any cylinder which does not produce a momentary
engine speed drop?
Ye s o r N o
Ye s > > G O T O 4 .
No >> GO TO 9.
4.CHECK FUEL INJECTOR
Does each fuel injector make an operating sound at idle?
Ye s o r N o
Ye s > > G O T O 5 .
No >> Check fuel injector(s) and circuit(s). Refer to EC-521
.
5.CHECK FUNCTION OF IGNITION COIL-I
CAUTION:
Do the following procedure in the place where ventilation is good without the combustible.
1. Turn ignition switch OFF.
2. Remove fuel pump fuse (1) in IPDM E/R (2) to release fuel pres-
sure.
NOTE:
Do not use CONSULT-II to release fuel pressure, or fuel pres-
sure applies again during the following procedure.
- : Vehicle front
3. Start engine.
4. After engine stalls, crank it two or three times to release all fuel
pressure.
5. Turn ignition switch OFF.
6. Remove all ignition coil harness connectors to avoid the electri-
cal discharge from the ignition coils.
7. Remove ignition coil and spark plug of the cylinder to be checked.
PBIB0133E
PBIA9870J
PBIB3332E
PBIB2958E

DTC P0300 - P0304 MULTIPLE CYLINDER MISFIRE, NO. 1 - 4 CYLINDER MIS-
FIRE
EC-287
< SERVICE INFORMATION >
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8. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
9. Connect spark plug and harness connector to ignition coil.
10. Fix ignition coil using a rope etc. with gap of 13 - 17 mm
between the edge of the spark plug and grounded metal portion
as shown in the figure.
11. Crank engine for about 3 seconds, and check whether spark is
generated between the spark plug and the grounded metal por-
tion.
CAUTION:
• Do not approach to the spark plug and the ignition coil
within 50cm. Be careful not to get an electrical shock
while checking, because the electrical discharge voltage
becomes 20kV or more.
• It might cause to damage the ignition coil if the gap of more than 17 mm is taken.
NOTE:
When the gap is less than 13 mm, the spark might be generated even if the coil is malfunctioning.
OK or NG
OK >> GO TO 9.
NG >> GO TO 6.
6.CHECK FUNCTION OF IGNITION COIL-II
1. Turn ignition switch OFF.
2. Disconnect spark plug and connect a known-good spark plug.
3. Crank engine for about 3 seconds, and recheck whether spark is generated between the spark plug and
the grounded metal portion.
OK or NG
OK >> GO TO 7.
NG >> Check ignition coil, power transistor and their circuits. Refer to EC-531
.
7.CHECK SPARK PLUG
Check the initial spark plug for fouling, etc.
OK or NG
OK >> Replace spark plug(s) with standard type one(s). For
spark plug type, refer to MA-17, "
Changing Spark
Plugs".
NG >> 1. Repair or clean spark plug.
2. GO TO 8.
8.CHECK FUNCTION OF IGNITION COIL-III
1. Reconnect the initial spark plugs.
2. Crank engine for about three seconds, and recheck whether spark is generated between the spark plug
and the grounded portion.
OK or NG
OK >>INSPECTION END
NG >> Replace spark plug(s) with standard type one(s). For spark plug type, refer to MA-17, "
Changing
Spark Plugs".
9.CHECK COMPRESSION PRESSURESpark should be generated.
PBIB2325E
Spark should be generated.
SEF156I
Spark should be generated.

DTC P0420 THREE WAY CATALYST FUNCTION
EC-311
< SERVICE INFORMATION >
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OK >> GO TO 6.
NG >> Perform EC-523, "
Diagnosis Procedure".
6.CHECK FUNCTION OF IGNITION COIL-I
CAUTION:
Do the following procedure in the place where ventilation is good without the combustible.
1. Turn ignition switch OFF.
2. Remove fuel pump (1) fuse in IPDM E/R (2) to release fuel pres-
sure.
NOTE:
Do not use CONSULT-II to release fuel pressure, or fuel pres-
sure applies again during the following procedure.
- : Vehicle front
3. Start engine.
4. After engine stalls, crank it two or three times to release all fuel
pressure.
5. Turn ignition switch OFF.
6. Remove all ignition coil harness connectors to avoid the electri-
cal discharge from the ignition coils.
7. Remove ignition coil and spark plug of the cylinder to be checked.
8. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
9. Connect spark plug and harness connector to ignition coil.
10. Fix ignition coil using a rope etc. with gap of 13 - 17 mm
between the edge of the spark plug and grounded metal portion
as shown in the figure.
11. Crank engine for about 3 seconds, and check whether spark is
generated between the spark plug and the grounded metal por-
tion.
CAUTION:
• Do not approach to the spark plug and the ignition coil
within 50cm. Be careful not to get an electrical shock
while checking, because the electrical discharge voltage
becomes 20kV or more.
• It might cause to damage the ignition coil if the gap of more than 17 mm is taken.
NOTE:
When the gap is less than 13 mm, the spark might be generated even if the coil is malfunctioning.
OK or NG
OK >> GO TO 10.
NG >> GO TO 7.
7.CHECK FUNCTION OF IGNITION COIL-II
1. Turn ignition switch OFF.
2. Disconnect spark plug and connect a known-good spark plug.
3. Crank engine for about 3 seconds, and recheck whether spark is generated between the spark plug and
the grounded metal portion.
OK or NG
OK >> GO TO 8.
NG >> Check ignition coil, power transistor and their circuits. Refer to EC-531
.
8.CHECK SPARK PLUGSpark should be generated.
PBIB2958E
PBIB2325E
Spark should be generated.

EC-312
< SERVICE INFORMATION >
DTC P0420 THREE WAY CATALYST FUNCTION
Check the initial spark plug for fouling, etc.
OK or NG
OK >> Replace spark plug(s) with standard type one(s). For
spark plug type, refer to MA-17, "
Changing Spark
Plugs".
NG >> 1. Repair or clean spark plug.
2. GO TO 9.
9.CHECK FUNCTION OF IGNITION COIL-III
1. Reconnect the initial spark plugs.
2. Crank engine for about 3 seconds, and recheck whether spark is generated between the spark plug and
the grounded portion.
OK or NG
OK >>INSPECTION END
NG >> Replace spark plug(s) with standard type one(s). For spark plug type, refer to MA-17, "
Changing
Spark Plugs".
10.CHECK FUEL INJECTOR
1. Turn ignition switch OFF.
2. Remove fuel injector assembly.
Refer to EM-33
.
Keep fuel hose and all fuel injectors connected to fuel tube.
3. Disconnect all ignition coil harness connectors.
4. Reconnect all fuel injector harness connectors disconnected.
5. Turn ignition switch ON.
Make sure fuel does not drip from fuel injector.
OK or NG
OK (Does not drip.)>>GO TO 11.
NG (Drips.)>>Replace the fuel injector(s) from which fuel is dripping.
11 .CHECK INTERMITTENT INCIDENT
Refer to EC-136
.
Trouble is fixed.>>INSPECTION END
Trouble is not fixed.>>Replace three way catalyst (manifold).
SEF156I
Spark should be generated.