ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-113
< FUNCTION DIAGNOSIS >[HR16DE (WITH EURO-OBD)]
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NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
ACTIVE TEST MODE
Test Item
*: Leaving cooling fan OFF with CONSULT-III while engine is running may cause the engine to overheat.
DTC & SRT CONFIRMATION MODE
SRT STATUS Mode
For details, refer to EC-94, "Diagnosis Description".
SRT WORK SUPPORT Mode
AT OD CANCEL ON/OFF Indicates the [ON/OFF] condition of A/T O/D can-
cel to the input signal from the TCM.
CRUISE LAMP ON/OFF Indicates [ON/OFF] condition of CRUISE lamp
determined by the ECM according to the input
signals.
SET LAMP ON/OFF Indicates [ON/OFF] condition of SET lamp deter-
mined by the ECM according to the input signals. Monitored item Unit Description Remarks
TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
FUEL INJECTION Engine: Return to the original
trouble condition
Change the amount of fuel injec-
tion using CONSULT-III.If trouble symptom disappears, see
CHECK ITEM. Harness and connectors
Fuel injector
Heated oxygen sensor 1
IGNITION TIMING Engine: Return to the original
trouble condition
Timing light: Set
Retard the ignition timing using
CONSULT-III.If trouble symptom disappears, see
CHECK ITEM. Perform Idle Air Volume Learn-
ing.
POWER BALANCE Engine: After warming up, idle the
engine.
A/C switch OFF
Shift lever: Neutral
Cut off each fuel injector signal
one at a time using CONSULT-III.Engine runs rough or dies. Harness and connectors
Compression
Fuel injector
Power transistor
Spark plug
Ignition coil
COOLING FAN* Ignition switch: ON
Turn the cooling fan “LOW”, “HI”
and “OFF” CONSULT-III.Cooling fan moves and stops. Harness and connectors
IPDM E/R (Cooling fan relay)
Cooling fan motor
ENG COOLANT
TEMP Engine: Return to the original
trouble condition
Change the engine coolant tem-
perature using CONSULT-III.If trouble symptom disappears, see
CHECK ITEM. Harness and connectors
Engine coolant temperature
sensor
Fuel injector
FUEL PUMP RELAY Ignition switch: ON (Engine
stopped)
Turn the fuel pump relay “ON”
and “OFF” using CONSULT-III
and listen to operating sound.Fuel pump relay makes the operat-
ing sound. Harness and connectors
Fuel pump relay
PURG VOL CONT/V Engine: After warming up, run en-
gine at 1,500 rpm.
Change the EVAP canister purge
volume control solenoid valve
opening percent using CON-
SULT-III.Engine speed changes according
to the opening percent. Harness and connectors
Solenoid valve
V/T ASSIGN ANGLE Engine: Return to the original
trouble condition
Change intake valve timing using
CONSULT-III.If trouble symptom disappears, see
CHECK ITEM. Harness and connectors
Intake valve timing control sole-
noid valve
EC-116
< COMPONENT DIAGNOSIS >[HR16DE (WITH EURO-OBD)]
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
COMPONENT DIAGNOSIS
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
DescriptionINFOID:0000000001670886
The specification (SP) value indicates the tolerance of the value that is displayed in “SPEC” of “DATA MONI-
TOR” mode of CONSULT-III during normal operation of the Engine Control System. When the value in “SPEC”
of “DATA MONITOR” mode is within the SP value, the Engine Control System is confirmed OK. When the
value in “SPEC” of “DATA MONITOR” mode is NOT within the SP value, the Engine Control System may have
one or more malfunctions.
The SP value is used to detect malfunctions that may affect the Engine Control System, but will not light the
MI.
The SP value will be displayed for the following three items:
B/FUEL SCHDL (The fuel injection pulse width programmed into ECM prior to any learned on board correc-
tion)
A/F ALPHA-B1 (The mean value of air-fuel ratio feedback correction factor per cycle)
MAS A/F SE-B1 (The signal voltage of the mass air flow sensor)
Component Function CheckINFOID:0000000001670887
1.START
Make sure that all of the following conditions are satisfied.
Vehicle driven distance: More than 5,000 km (3,107 miles)
Barometric pressure: 98.3 - 104.3 kPa (0.983 - 1.043 bar, 1.003 - 1.064 kg/cm
2, 14.25 - 15.12 psi)
Atmospheric temperature: 20 - 30°C (68 - 86°F)
Engine coolant temperature: 75 - 95°C (167 - 203°F)
Transmission: Warmed-up
- After the engine is warmed up to normal operating temperature, drive vehicle for 5 minutes.
Electrical load: Not applied*
Engine speed: Idle
*: Rear window defogger switch, air conditioner switch, lighting switch are OFF. Steering wheel is straight
ahead.
>> GO TO 2.
2.PERFORM “SPEC” OF “DATA MONITOR” MODE
With CONSULT-III
NOTE:
Perform “SPEC” in “DATA MONITOR” mode in maximum scale display.
1. Perform EC-22, "
BASIC INSPECTION : Special Repair Requirement".
2. Select “B/FUEL SCHDL”, “A/F ALPHA-B1” and “MAS A/F SE-B1” in “SPEC” of “DATA MONITOR” mode
with CONSULT-III.
3. Make sure that monitor items are within the SP value.
Is the inspection result normal?
YES >> END
NO >> Go to EC-117, "
Diagnosis Procedure".
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
EC-121
< COMPONENT DIAGNOSIS >[HR16DE (WITH EURO-OBD)]
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15.DISCONNECT AND RECONNECT ECM HARNESS CONNECTOR
1. Stop the engine.
2. Disconnect ECM harness connector. Check pin terminal and connector for damage, and then reconnect it.
>> GO TO 16.
16.CHECK “A/F ALPHA-B1”
1. Start engine.
2. Select “A/F ALPHA-B1” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within
the SP value.
Is the measurement value within the SP value?
YES >> INSPECTION END
NO >> Detect malfunctioning part according to EC-366, "
Symptom Table".
17.CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within the
SP value.
Is the measurement value within the SP value?
YES >> INSPECTION END
NO-1 >> More than the SP value: GO TO 18.
NO-2 >> Less than the SP value: GO TO 25.
18.DETECT MALFUNCTIONING PART
1. Check for the cause of large engine friction. Refer to the following.
- Engine oil level is too high
- Engine oil viscosity
- Belt tension of alternator, A/C compressor, etc. is excessive
- Noise from engine
- Noise from transmission, etc.
2. Check for the cause of insufficient combustion. Refer to the following.
- Valve clearance malfunction
- Intake valve timing control function malfunction
- Camshaft sprocket installation malfunction, etc.
>> Repair or replace malfunctioning part, and then GO TO 30.
19.CHECK INTAKE SYSTEM
Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.
Crushed air ducts
Malfunctioning seal of air cleaner element
Uneven dirt of air cleaner element
Improper specification of intake air system
Is the inspection result normal?
YES >> GO TO 21.
NO >> Repair or replace malfunctioning part, and then GO TO 20.
20.CHECK “A/F ALPHA-B1”, AND “B/FUEL SCHDL”
Select “A/F ALPHA-B1” and “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and make sure that the
each indication is within the SP value.
Is the measurement value within the SP value?
YES >>INSPECTION END
NO >> “B/FUEL SCHDL” is more, “A/F ALPHA-B1” is less than the SP value: GO TO 21.
21.DISCONNECT AND RECONNECT MASS AIR FLOW SENSOR HARNESS CONNECTOR
1. Stop the engine.
2. Disconnect mass air flow sensor harness connector. Check pin terminal and connector for damage and
then reconnect it again.
EC-122
< COMPONENT DIAGNOSIS >[HR16DE (WITH EURO-OBD)]
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
>> GO TO 22.
22.CHECK “A/F ALPHA-B1”
1. Start engine.
2. Select “A/F ALPHA-B1” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within
the SP value.
Is the measurement value within the SP value?
YES >> Detect malfunctioning part of mass air flow sensor circuit and repair it. Refer to EC-134, "DTC
Logic". Then GO TO 29.
NO >> GO TO 23.
23.CHECK “MAS A/F SE-B1”
Select “MAS A/F SE-B1” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within the
SP value.
Is the measurement value within the SP value?
YES >> GO TO 24.
NO >> More than the SP value: Replace mass air flow sensor, and then GO TO 29.
24.REPLACE ECM
1. Replace ECM.
2. Go to EC-25, "
ADDITIONAL SERVICE WHEN REPLACING CONTROL UNIT : Special Repair Require-
ment".
>> GO TO 29.
25.CHECK INTAKE SYSTEM
Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.
Crushed air ducts
Malfunctioning seal of air cleaner element
Uneven dirt of air cleaner element
Improper specification of intake air system
Is the inspection result normal?
YES >> GO TO 27.
NO >> Repair or replace malfunctioning part, and then GO TO 26.
26.CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within the
SP value.
Is the measurement value within the SP value?
YES >> INSPECTION END
NO >> Less than the SP value: GO TO 27.
27.CHECK “MAS A/F SE-B1”
Select “MAS A/F SE-B1” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within the
SP value.
Is the measurement value within the SP value?
YES >> GO TO 28.
NO >> Less than the SP value: Replace mass air flow sensor, and then GO TO 30.
28.CHECK INTAKE SYSTEM
Check for the cause of air leak after the mass air flow sensor. Refer to the following.
Disconnection, looseness, and cracks in air duct
Looseness of oil filler cap
Disconnection of oil level gauge
Open stuck, breakage, hose disconnection, or cracks of PCV valve
Disconnection or cracks of EVAP purge hose, open stuck of EVAP canister purge volume control solenoid
valve
P0135 HO2S1 HEATER
EC-163
< COMPONENT DIAGNOSIS >[HR16DE (WITH EURO-OBD)]
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P0135 HO2S1 HEATER
DescriptionINFOID:0000000001670928
SYSTEM DESCRIPTION
The ECM performs ON/OFF duty control of the heated oxygen sensor 1 heater corresponding to the engine
speed and engine coolant temperature. The duty percent varies with engine coolant temperature when engine
is started.
DTC LogicINFOID:0000000001670929
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than between 11V at
idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Wait at least 5 seconds.
3. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-163, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000001670930
1.CHECK GROUND CONNECTION
1. Turn ignition switch OFF.
2. Check ground connection E15. Refer to Ground Inspection in GI-58, "
Circuit Inspection".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace ground connection.
2.CHECK HO2S1 POWER SUPPLY CIRCUIT
1. Disconnect heated oxygen sensor 1 harness connector.
2. Turn ignition switch ON.
3. Check the voltage between HO2S1 sensor 1 harness connector and ground.
Sensor Input Signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)Engine speed
Heated oxygen sensor 1
heater controlHeated oxygen sensor 1
heater
Mass air flow sensor Amount of intake air
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0135Heated oxygen sensor 1
heater control circuit lowThe current amperage in the heated oxygen sensor
1 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the heated oxygen sensor 1 heater.) Harness or connectors
(The heated oxygen sensor 1 heater
circuit is open or shorted.)
Heated oxygen sensor 1 heater
EC-176
< COMPONENT DIAGNOSIS >[HR16DE (WITH EURO-OBD)]
P0141 HO2S2 HEATER
P0141 HO2S2 HEATER
DescriptionINFOID:0000000001670941
SYSTEM DESCRIPTION
The ECM performs ON/OFF control of the heated oxygen sensor 2 heater corresponding to the engine speed,
amount of intake air and engine coolant temperature.
OPERATION
DTC LogicINFOID:0000000001670942
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON and wait at least 5 seconds.
2. Check 1st trip DTC.
Is 1st tip DTC detected?
YES >> Go to EC-176, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000001670943
1.CHECK GROUND CONNECTION
1. Turn ignition switch OFF.
2. Check ground connection E15. Refer to Ground Inspection in GI-58, "
Circuit Inspection".
Is the inspection result normal?
Sensor Input signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)Engine speed
Heated oxygen sensor 2
heater controlHeated oxygen sensor 2 heater
Engine coolant temperature sensor Engine coolant temperature
Mass air flow sensor Amount of intake air
Engine speed rpm Heated oxygen sensor 2 heater
Above 3,600OFF
Below 3,600 rpm after the following conditions are met.
Engine: After warming up
Keeping the engine speed between 3,500 and 4,000 rpm for 1
minute and at idle for 1 minute under no loadON
DTC No.Trouble diagnosis
nameDTC detecting condition Possible cause
P0141Heated oxygen
sensor 2 heater
control circuit lowThe current amperage in the heated oxygen sen-
sor 2 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.) Harness or connectors
(The heated oxygen sensor 2 heater circuit is
open or shorted.)
Heated oxygen sensor 2 heater
P0171 FUEL INJECTION SYSTEM FUNCTION
EC-179
< COMPONENT DIAGNOSIS >[HR16DE (WITH EURO-OBD)]
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P0171 FUEL INJECTION SYSTEM FUNCTION
DTC LogicINFOID:0000000001670945
DTC DETECTION LOGIC
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. The
ECM calculates the necessary compensation to correct the offset between the actual and the theoretical
ratios.
In case the amount of the compensation value is extremely large (The actual mixture ratio is too lean.), the
ECM judges the condition as the fuel injection system malfunction and lights up the MI (2 trip detection logic).
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE-I
1. Clear the mixture ratio self-learning value. Refer to EC-29, "
MIXTURE RATIO SELF-LEARNING VALUE
CLEAR : Special Repair Requirement".
2. Start engine.
Is it difficult to start engine?
YES >> GO TO 3.
NO >> GO TO 4.
3.RESTART ENGINE
If it is difficult to start engine, the fuel injection system has a malfunction, too.
Crank engine while depressing accelerator pedal.
Does engine start?
YES >> Go to EC-180, "Diagnosis Procedure".
NO >> Check exhaust and intake air leak visually.
4.PERFORM DTC CONFIRMATION PROCEDURE-II
1. Start engine and let it idle for at least 10 minutes.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-180, "Diagnosis Procedure".
NO >> GO TO 5.
5.PERFORM DTC CONFIRMATION PROCEDURE-III
1. Turn ignition switch OFF and wait at least 10 seconds.
Sensor Input signal to ECM ECM function Actuator
Heated oxygen sensor 1Density of oxygen in exhaust gas
(Mixture ratio feedback signal)Fuel injection control Fuel injector
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0171Fuel injection system too
lean Fuel injection system does not operate properly.
The amount of mixture ratio compensation is too
large. (The mixture ratio is too lean.) Intake air leaks
Heated oxygen sensor 1
Fuel injector
Exhaust gas leaks
Incorrect fuel pressure
Lack of fuel
Mass air flow sensor
Incorrect PCV hose connection
P0172 FUEL INJECTION SYSTEM FUNCTION
EC-183
< COMPONENT DIAGNOSIS >[HR16DE (WITH EURO-OBD)]
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P0172 FUEL INJECTION SYSTEM FUNCTION
DTC LogicINFOID:0000000001670947
DTC DETECTION LOGIC
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. The
ECM calculates the necessary compensation to correct the offset between the actual and the theoretical
ratios.
In case the amount of the compensation value is extremely large (The actual mixture ratio is too rich.), the
ECM judges the condition as the fuel injection system malfunction and lights up the MI (2 trip detection logic).
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE-I
1. Clear the mixture ratio self-learning value. Refer to EC-29, "
MIXTURE RATIO SELF-LEARNING VALUE
CLEAR : Special Repair Requirement".
2. Start engine.
Is it difficult to start engine?
YES >> GO TO 3.
NO >> GO TO 4.
3.RESTART ENGINE
If it is difficult to start engine, the fuel injection system has a malfunction, too.
Crank engine while depressing accelerator pedal.
Does engine start?
YES >> Go to EC-184, "Diagnosis Procedure".
NO >> Remove spark plugs and check for fouling, etc.
4.PERFORM DTC CONFIRMATION PROCEDURE-II
1. Start engine and let it idle for at least 10 minutes.
Is 1st trip DTC detected?
YES >> Go to EC-184, "Diagnosis Procedure".
NO >> GO TO 5.
5.PERFORM DTC CONFIRMATION PROCEDURE-III
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Start engine and drive the vehicle under the similar conditions to (1st trip) Freeze Frame Data for 10 min-
utes. Refer to the table below.
Hold the accelerator pedal as steady as possible.
Sensor Input signal to ECM ECM function Actuator
Heated oxygen sensor 1Density of oxygen in exhaust gas
(Mixture ratio feedback signal)Fuel injection control Fuel injector
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0172Fuel injection system too
rich Fuel injection system does not operate properly.
The amount of mixture ratio compensation is too
large. (The mixture ratio is too rich.) Heated oxygen sensor 1
Fuel injector
Exhaust gas leaks
Incorrect fuel pressure
Mass air flow sensor