Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-45
Engine has no powerFaulty spark plug “Spark Plug Inspection in Section 1H”
Faulty ignition coil with ignitor “Ignition Coil Assembly (Including ignitor)
Inspection in Section 1H”
Leaks, loose connection or
disconnection of high-tension cord “High-Tension Cord Removal and Installation
in Section 1H”
Faulty knock sensor “DTC P0327 / P0328: Knock Sensor 1 Circuit
Low / High”
Clogged fuel hose or pipe “Fuel Pressure Check”
Malfunctioning fuel pump “Fuel Pump and Its Circuit Check”
Air drawn in through intake manifold
gasket or throttle body gasket
Engine overheating Condition “Engine overheating”
Malfunctioning EGR valve “EGR Valve Inspection in Section 1B”
Poor performance of ECT sensor or
MAF sensor “ECT Sensor Inspection in Section 1C” or
“MAF and IAT Sensor Inspection in Section
1C”
Faulty electric throttle body assembly “Electric Throttle Body Assembly On-Vehicle
Inspection in Section 1C”
Faulty APP sensor assembly “APP Sensor Assembly Inspection in Section
1C”
Faulty fuel injector(s) “Fuel Injector Circuit Check”
Faulty ECM
Dragging brakes Condition “Dragging brakes” in “Brakes
Symptom Diagnosis in Section 4A”
Slipping clutch Condition “Slipping clutch” in “Clutch System
Symptom Diagnosis in Section 5C”
Low compression “Compression Check in Section 1D”
Camshaft position control (VVT) system
out of order “Oil Control Valve Inspection in Section 1D”
Improper engine idling or
engine fails to idle Faulty spark plug
“Spark Plug Inspection in Section 1H”
Leaky or disconnected high-tension cord “High-Tension Cord Removal and Installation
in Section 1H”
Faulty ignition coil with ignitor “Ignition Coil Assembly (Including ignitor)
Inspection in Section 1H”
Fuel pressure out of specification “Fuel Pressure Check”
Leaky manifold, throttle body, or cylinder
head gasket
Malfunctioning EGR valve “EGR Valve Inspection in Section 1B”
Faulty evaporative emission control
system “EVAP Canister Purge Inspection in Section
1B”
Faulty EGR system “EGR System Inspection in Section 1B”
Faulty fuel injector(s) “Fuel Injector Circuit Check”
Poor performance of ECT sensor or
MAF sensor “ECT Sensor Inspection in Section 1C” or
“MAF and IAT Sensor Inspection in Section
1C”
Faulty electric throttle body assembly “Electric Throttle Body Assembly On-Vehicle
Inspection in Section 1C”
Faulty APP sensor assembly “APP Sensor Assembly Inspection in Section
1C”
Faulty ECM
Loose connection or disconnection of
vacuum hoses
Malfunctioning PCV valve “PCV Valve Inspection in Section 1B”
Engine overheating Condition “Engine overheating”
Low compression “Compression Check in Section 1D”
Camshaft position control (VVT) system
out of order “Oil Control Valve Inspection in Section 1D”
Condition Possible cause Correction / Reference Item
Downloaded from www.Manualslib.com manuals search engine 1A-46 Engine General Information and Diagnosis:
Excessive hydrocarbon
(HC) emission or carbon
monoxide (CO)Faulty spark plug
“Spark Plug Inspection in Section 1H”
Leaky or disconnected high-tension cord “High-Tension Cord Removal and Installation
in Section 1H”
Faulty ignition coil with ignitor “Ignition Coil Assembly (Including ignitor)
Inspection in Section 1H”
Low compression “Compression Check in Section 1D”
Lead contamination of three way
catalytic converter Check for absence of f
iller neck restrictor.
Faulty evaporative emission control
system “EVAP Canister Purge Inspection in Section
1B”
Fuel pressure out of specification “Fuel Pressure Check”
Closed loop system (A/F feedback
compensation) fails (Faulty TP sensor,
Poor performance of ECT sensor or
MAF sensor) “Electric Throttle Body Assembly On-Vehicle
Inspection in Section 1C”, “ECT Sensor
Inspection in Section 1C” or “MAF and IAT
Sensor Inspection in Section 1C”
Faulty electric throttle body assembly “Electric Throttle Body Assembly On-Vehicle
Inspection in Section 1C”
Faulty APP sensor assembly “APP Sensor Assembly Inspection in Section
1C”
Faulty injector(s) “Fuel Injector Circuit Check”
Faulty ECM
Engine not at normal operating
temperature
Clogged air cleaner “Air Cleaner Element Inspection and Cleaning
in Section 1D”
Vacuum leaks “Engine Vacuum Check in Section 1D”
Camshaft position control (VVT) system
out of order “Oil Control Valve Inspection in Section 1D”
Excessive nitrogen
oxides (NOx) emission Improper ignition timing
“Ignition Timing Inspection in Section 1H”
Lead contamination of catalytic
converter Check for absence of f
iller neck restrictor.
Faulty EGR system “EGR System Inspection in Section 1B”
Fuel pressure out of specification “Fuel Pressure Check”
Closed loop system (A/F feedback
compensation) fails (Faulty TP sensor,
Poor performance of ECT sensor or
MAF sensor) “Electric Throttle Body Assembly On-Vehicle
Inspection in Section 1C”, “ECT Sensor
Inspection in Section 1C” or “MAF and IAT
Sensor Inspection in Section 1C”
Faulty electric throttle body assembly “Electric Throttle Body Assembly On-Vehicle
Inspection in Section 1C”
Faulty APP sensor assembly “APP Sensor Assembly Inspection in Section
1C”
Faulty injector(s) “Fuel Injector Circuit Check”
Faulty ECM
Camshaft position control (VVT) system
out of order “Oil Control Valve Inspection in Section 1D”
Condition Possible cause Correction / Reference Item
Downloaded from www.Manualslib.com manuals search engine 1A-50 Engine General Information and Diagnosis:
Circuit Description
Actual valve timing fails to become close to target advance level of each function although advance control function or
retarded advance control function is at work.
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure 1) Clear DTC. Refer to “DTC Clearance”.
2) Start engine and keep it at idle for 10 seconds.
3) Check DTC. Refer to “DTC Check”.
DTC Troubleshooting
NOTE
• When measuring circuit voltage, resistance and/ or pulse signal at ECM connector, connect the
special tool to ECM and/or the ECM connectors re ferring to “Inspection of ECM and Its Circuits”.
• Upon completion of inspection and repair work, perform “DTC Confirmation Procedure” and confirm that the trouble has been corrected.
DTC detecting condition Trouble area
Monitor signal of oil control valve is different from
command signal. (Circuit open or short)
(1 driving cycle detection logic) • Oil control valve
• Oil control valve circuit
•ECM
Step
Action YesNo
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2.
Go to “Engine and
Emission Control
System Check”.
2 Oil control valve electrical circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Check for proper connection at “C37-60” and “C37-59” terminals of ECM connector.
3) If OK, measure resistance between “C37-60” and “C37- 59” terminals of ECM connector.
Is resistance below 10
Ω? Go to Step 3. Go to Step 8.
3 Oil control valve electrical circuit check
Was resistance more than 6.5
Ω in Step 2? Go to Step 4. Go to Step 7.
4 Oil control valve electrical circuit for power short check
1) Turn ON ignition switch.
2) Measure voltage between “C37-60” terminal of ECM
connector and engine ground.
Is voltage below 1 V? Go to Step 5. “RED”, “YEL/RED”,
“YEL” or “YEL/GRN”
wire is shorted to power
supply circuit.
5 Oil control valve electrical circuit for ground short
check
1) Disconnect connector from oil control valve with ignition
switch turned OFF.
2) Measure resistance between “C37-60” terminal of ECM connector and engine ground.
Is resistance infinity? Go to Step 6. “YEL/RED” wire is
shorted to ground
circuit.
Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-51
6Oil control valve electrical circuit for ground short
check
1) Measure resistance between “C37-59” terminal of ECM
connector and engine ground.
Is resistance infinity? Go to Step 9.
“YEL/GRN” wire is
shorted to ground
circuit.
7 Oil control valve electrical circuit for short check
1) Disconnect connector from oil control valve with ignition
switch turned OFF.
2) Measure resistance between “C37-60” and “C37-59” terminals of ECM connector.
Is resistance infinity? Go to Step 9.
“YEL/RED” wire is
shorted to “YEL/GRN”
wire.
8 Oil control valve electrical circuit check
1) Disconnect connector from oil control valve with ignition
switch turned OFF.
2) Measure resistance between “C37-60” terminal of ECM connector and “YEL/RED” wire terminal of oil control
valve connector and between “C37-59” terminal of ECM
connector and “YEL/GRN” wir e terminal of oil control
valve connector.
Is resistance below 1
Ω? Go to Step 9. “YEL/RED” or “YEL/
GRN” wire circuit is
open or high resistance.
9 Oil control valve check
Check oil control valve refe rring to “Oil Control Valve
Inspection in Section 1D”.
Is resistance within specified value? Substitute a known-
good ECM and recheck.
Faulty oil control valve.
Step Action Yes No
Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-55
StepAction YesNo
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2.
Go to “Engine and
Emission Control
System Check”.
2 HO2S-1 heater power circuit check
1) Disconnect connector from HO 2S-1 with ignition switch
turned OFF.
2) Check for proper connection to HO2S-1 at “BLK/WHT” and “BLK/RED” wire terminals.
3) If wire and connection are OK, measure voltage between “BLK/WHT” wire terminal and engine ground
with ignition switch turned ON.
Is voltage over 10 V? Go to Step 3.
“BLK/WHT” wire is open
circuit or shorted to
ground circuit.
3 HO2S-1 heater power circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Measure resistance between “BLK/WHT” wire terminal of HO2S-1 connector and “E 23-29” terminal of ECM
connector.
Is resistance below 5
Ω? Go to Step 4. “BLK/WHT” wire is high
resistance circuit.
4 HO2S-1 heater drive circuit check
1) Measure resistance between “C37-46” terminal of ECM
connector and vehicle body ground.
Is resistance infinity? Go to Step 5. “BLK/RED” wire is
shorted to ground
circuit.
5 HO2S-1 heater drive circuit check
1) Turn ON ignition switch.
2) Measure voltage between “C37-46” terminal of ECM
connector and vehicle body ground.
Is voltage 0 V? Go to Step 6. “BLK/RED” wire is
shorted to power circuit.
6 HO2S-1 heater drive circuit check
1) Connect connector to HO2S-1 with ignition switch turned
OFF.
2) Turn ON ignition switch.
3) Measure voltage between “C37-46” terminal of ECM connector and vehicle body ground with connector
disconnected from ECM.
Is voltage over 10 V? Go to Step 7. “BLK/RED” wire is open
circuit.
7 HO2S-1 heater check
1) Disconnect HO2S-1 connector with ignition switch
turned OFF.
2) Check HO2S-1 heater resistance referring to “HO2S-1 and HO2S-2 Heater On-Vehicle Inspection in Section
1C”.
Is resistance within specified value range? Go to Step 8. Replace HO2S-1.
8 HO2S-1 heater power circuit check
1) Connect connector to HO2S-1 with ignition switch turned
OFF.
2) Measure resistance between “E23-29” and “C37-46” terminals of ECM connector.
It resistance below 12
Ω? Substitute a known-
good ECM and recheck.
“BLK/WHT”, “BLK/RED”
and / or “BLK” wire is
high resistance circuit.
Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-57
StepAction YesNo
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2.
Go to “Engine and
Emission Control
System Check”.
2 HO2S-2 heater power circuit check
1) Disconnect connector from HO 2S-2 with ignition switch
turned OFF.
2) Check for proper connection to HO2S-2 at “BLK/WHT” and “RED/BLU” wire terminals.
3) If wire and connection are OK, measure voltage between “BLK/WHT” wire terminal of HO2S-2 connector
and engine ground with ignition switch turned ON.
Is voltage over 10 V? Go to Step 3.
“BLK/WHT” wire is open
circuit or shorted to
ground circuit.
3 HO2S-2 heater power circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Measure resistance between “BLK/WHT” wire terminal of HO2S-2 connector and “E23-29” terminal wire of ECM
connector.
Is resistance below 5
Ω? Go to Step 4. “BLK/WHT” wire is high
resistance circuit.
4 HO2S-2 heater drive circuit check
1) Measure resistance between “RED/BLU” wire terminal of
HO2S-2 connector and vehicle body ground.
Is resistance infinity? Go to Step 5. “RED/BLU” wire is
shorted to ground
circuit.
5 HO2S-2 heater drive circuit check
1) Turn ON ignition switch.
2) Measure voltage between “RED/BLU” wire terminal of
HO2S-2 connector and vehicle body ground.
Is voltage 0 V? Go to Step 6. “RED/BLU” wire is
shorted to power circuit.
6 HO2S-2 heater drive circuit check
1) Connect connector to HO2S-2 with ignition switch turned
OFF.
2) Turn ON ignition switch.
3) Measure voltage between “C37-47” terminal of disconnected ECM connector and vehicle body ground.
Is voltage over 10 V? Go to Step 7.
“RED/BLU” wire is open
circuit.
7 HO2S-2 heater check
1) Disconnect HO2S-2 connector with ignition switch
turned OFF.
2) Check HO2S-2 heater resistance referring to “HO2S-1 and HO2S-2 Heater On-Vehicle Inspection in Section
1C”.
Is resistance within specified value? Go to Step 8.
Replace HO2S-2.
8 HO2S-2 heater power circuit check
1) Connect connector to HO2S-2 with ignition switch turned
OFF.
2) Measure resistance between “E23-29” and “C37-47” terminals of ECM connector.
Is resistance below 30
Ω? Substitute a known-
good ECM and recheck.
“RED/BLU” wire is high
resistance circuit.
Downloaded from www.Manualslib.com manuals search engine 1A-60 Engine General Information and Diagnosis:
4MAF sensor output voltage check
1) Turn OFF ignition switch.
2) Remove ECM from its br acket with ECM connectors
connected.
3) Measure voltage between “C37-26” and “C37-27” terminals of ECM connector referring to “MAF and IAT
Sensor On-Vehicle Inspection in Section 1C”.
Is each value within specified range? Poor “C37-26” and/or
“C37-27” terminal
connection.
If OK, substitute a
known-good ECM and
recheck.
Go to Step 5.
5 MAF sensor power supply voltage check
1) Disconnect connector from MAF and IAT sensor with
ignition switch turned OFF.
2) Turn ON ignition switch, measure voltage between engine ground and “BLK/RED” wire terminal (2) of MAF
and IAT sensor connector (1).
Is voltage 10 – 14 V? Go to Step 6. “BLK/RED” wire is open
circuit.
6 MAF sensor ground circuit check
1) Turn OFF ignition switch, measure resistance between
“GRY” wire terminal of MAF and IAT sensor connector
and engine ground.
Is resistance below 5
Ω? Go to Step 8.
Go to Step 7.
7 Ground circuit check
1) Measure resistance between “C37-27” terminal of ECM
connector and vehicle body ground.
Is resistance below 5
Ω? “GRY” wire is open or
high resistance circuit.
ECM grounds “E23-31”,
“C37-58”, “C37-15” and/
or “C37-30” circuit is
open or high resistance.
If wires are OK,
substitute a known-
good ECM and recheck.
8 MAF sensor signal circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Turn ON ignition switch, measure voltage between “GRN/BLK” wire terminal of MAF and IAT sensor
connector and engine ground.
Is voltage 0 V? Go to Step 9. “GRN/BLK” wire is
shorted to other circuit.
9 MAF sensor signal circuit check
1) Turn OFF ignition switch, measure resistance between
“GRN/BLK” wire terminal of MAF and IAT sensor
connector and engine ground.
Is resistance infinity? Go to Step 10. “GRN/BLK” wire is
shorted to ground
circuit.
Step Action Yes No
I4RS0A110020-01
Downloaded from www.Manualslib.com manuals search engine 1A-62 Engine General Information and Diagnosis:
3MAF sensor power supply voltage check
1) Disconnect connector from MAF and IAT sensor with
ignition switch turned OFF.
2) Turn ON ignition switch, measure voltage between engine ground and “BLK/RED” wire terminal of MAF and
IAT sensor connector.
Is voltage 10 – 14 V? Go to Step 4. “BLK/RED” wire is open
circuit.
4 MAF sensor ground circuit check
1) Turn OFF ignition switch, measure resistance between
“GRY” wire terminal of MAF and IAT sensor connector
and engine ground.
Is resistance below 5
Ω? Go to Step 6.
Go to Step 5.
5 Ground circuit check
1) Remove ECM from its br acket with ECM connectors
connected.
2) Measure resistance between “C37-27” terminal of ECM connector and engine ground.
Is resistance below 5
Ω? “GRY” wire is open or
high resistance circuit.
ECM grounds “E23-31”,
“C37-58”, “C37-15” and/
or “C37-30” circuit is
open or high resistance.
If wires are OK,
substitute a known-
good ECM and recheck.
6 MAF sensor signal circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Measure voltage between “GRN/BLK” wire terminal of MAF and IAT sensor connector and engine ground with
ignition switch turned ON.
Is voltage 0 V? Go to Step 7. “GRN/BLK” wire is
shorted to other circuit.
7 MAF sensor signal circuit check
1) Measure resistance between “GRN/BLK” wire terminal
of MAF and IAT sensor connector and engine ground
with ignition swit ch turned OFF.
Is resistance infinity? Go to Step 8.
“GRN/BLK” wire is
shorted to ground
circuit.
8 MAF sensor signal circuit check
1) Measure resistance between “GRN/BLK” wire terminal
of MAF and IAT sensor connector and “C37-26” terminal
of ECM connector.
Is resistance below 3
Ω? Go to Step 9.
“GRN/BLK” wire is open
or high resistance
circuit.
9 MAF sensor output signal check
1) Connect connectors to MAF and IAT sensor and ECM
with ignition swit ch turned OFF.
2) Measure voltage between “C37-26” and “C37-27” terminals of ECM connector referring to “MAF and IAT
Sensor On-Vehicle Inspection in Section 1C”.
Is each value within specified range? Substitute a known-
good ECM and recheck.
Faulty MAF and IAT
sensor.
Step
Action YesNo