6A±6
ENGINE MECHANICAL (6VE1 3.5L)
Rough Engine Idling or Engine Stalling
ConditionPossible causeCorrection
Trouble in fuel injection systemThrottle shutting off incompleteCorrect or replace
Throttle position sensor circuit open
or shortedCorrect or replace
Fuel injector circuits open or shortedCorrect or replace
Fuel injectors damagedReplace
Fuel pump relay defectiveReplace
Mass Airflow Sensor circuit open or
poor connectionsCorrect or replace
Mass Airflow Sensor defectiveReplace
Manifold Absolute Pressure Sensor
circuit open or poor connectionsCorrect or replace
Manifold Absolute Pressure Sensor
defectiveReplace
Engine Coolant Temperature Sensor
circuit open or poor connectionsCorrect or replace
Engine Coolant Temperature Sensor
defectiveReplace
Intake Air Temperature sensor circuit
open or poor connectionsCorrect or replace
Intake Air Temperature sensor
defectiveReplace
Ion Sensing Module cable broken or
poor connectionsCorrect or replace
Ion Sensing Module defectiveReplace
Vehicle Speed Sensor circuit open or
shortedCorrect or replace
Vehicle Speed Sensor defectiveReplace
Trouble in emission control systemPowertrain Control Module defectiveReplace
Exhaust Gas Recirculation Valve
circuit open or poor connectionsCorrect or replace
Exhaust Gas Recirculation Valve
faultyReplace
Canister purge valve circuit open or
poor connectionsCorrect or replace
Canister purge valve defectiveReplace
Evaporative Emission Canister
Purge control valve defectiveReplace
Trouble in ignition systemRefer to ªHard Startº
OthersEngine lacks compressionRefer to ªHard Startº
Valve incorrectly seatedLap valve
Air Cleaner Filter cloggedReplace filter element
Valve timing incorrectReadjust
Idle air control valve brokenReplace
Fast idle solenoid defectiveReplace
Positive Crankcase Ventilation valve
defective or cloggedReplace
6A±7
ENGINE MECHANICAL (6VE1 3.5L)
Rough Engine Running
ConditionPossible causeCorrection
Engine misfires periodicallyIgnition coil layer shortedReplace
Spark plugs foulingClean or install hotter type plug
Spark plug(s) insulator nose leakingReplace
Fuel injector(s) defectiveReplace
Powertrain control module faultyReplace
Engine knocks periodicallySpark plugs running too hotInstall colder type spark plugs
Powertrain control module faultyReplace
Ion Sensing module faultyRefer or replace
Engine lacks powerSpark plugs fouledClean
Fuel injectors defectiveReplace
Mass Airflow Sensor or Intake
Airflow Sensor circuit defectiveCorrect or replace
Manifold Absolute Pressure (MAP)
Sensor or Manifold Absolute
Pressure Sensor circuit defectiveCorrect or replace
Engine Coolant Temperature Sensor
or Engine Coolant Temperature
Sensor circuit defectiveCorrect or replace
Powertrain Control Module faultyReplace
Intake Air Temperature Sensor or
Intake Air Temperature Sensor
circuit defectiveCorrect or replace
Throttle Position Sensor or Throttle
Position Sensor circuit defectiveCorrect or replace
ION Sensing Module or ION Sensing
Module circuits defectiveCorrect or replace
6A±8
ENGINE MECHANICAL (6VE1 3.5L)
Hesitation
ConditionPossible causeCorrection
Hesitation on accelerationThrottle Position Sensor adjustment
incorrectReplace throttle valve assembly
Throttle Position Sensor circuit open
or shortedCorrect or replace
Mass Airflow Sensor circuit open or
poor connectionsCorrect or replace
Mass Airflow Sensor defectiveReplace
Manifold Absolute Pressure (MAP)
Sensor circuit open or shortedCorrect or replace
MAP Sensor defectiveReplace
Intake Air Temperature (IAT) Sensor
circuit open or poor connectionsCorrect or replace
Ion Sensing Module circuit open or
poor connectionsCorrect or replace
Ion Sensing Module defectiveReplace
IAT Sensor defectiveReplace
Hesitation at high speedsFuel tank strainer cloggedClean or replace
(Fuel pressure too low)Fuel pipe cloggedClean or replace
Fuel filter cloggedReplace
Defective fuel pump systemCheck and replace
Fuel Pressure Control Valve leakingReplace
Hesitation at high speeds
(Fuel injector not working normally)Power supply or ground circuit for
Multiport Fuel Injection System
shorted or openCheck and correct or replace
Fuel Injector defectiveReplace
Cable of Multiport Fuel Injection
System circuit open or poor
connectionsCorrect or replace
6A±9
ENGINE MECHANICAL (6VE1 3.5L)
Condition CorrectionPossible cause
Hesitation at high speedsPowertrain Control Module defectiveReplace
Throttle Position Sensor cable
broken or poor connectionsCorrect or replace
Throttle Position Sensor defectiveReplace
Engine Coolant Temperature Sensor
circuit open or shortedCorrect or replace
Engine Coolant Temperature Sensor
defectiveReplace
Mass Airflow Sensor circuit open or
poor connectionsCorrect or replace
Mass Airflow Sensor defectiveReplace
MAP Sensor cable broken or poor
connectionsCorrect or replace
MAP Sensor defectiveReplace
IAT Sensor circuit open or poor
connectionsCorrect or replace
IAT Sensor defectiveReplace
Ion Sensing Module circuit open or
poor connectionsCorrect or replace
Ion Sensing Module defectiveReplace
Throttle valve not fully openedCheck and correct or replace
Air Cleaner Filter cloggedReplace filter element
Power supply voltage too lowCheck and correct or replace
6A±10
ENGINE MECHANICAL (6VE1 3.5L)
Engine Lacks Power
ConditionPossible causeCorrection
Trouble in fuel systemFuel Pressure Control Valve not
working normallyReplace
Fuel injector cloggedClean or replace
Fuel pipe cloggedClean
Fuel filter clogged or fouledReplace
Fuel pump drive circuit not working
normallyCorrect or replace
Fuel tank not sufficiently breathing
due to clogged Evaporative
Emission Control System circuitClean or replace
Water in fuel systemClean
Inferior quality fuel in fuel systemUse fuel of specified octane rating
Powertrain Control Module supplied
poor voltageCorrect circuit
Throttle Position Sensor cable
broken or poor connectionsCorrect or replace
Throttle Position Sensor defectiveReplace
Mass Airflow Sensor not working
normallyReplace
Manifold Absolute Pressure Sensor
not working normallyReplace
Intake Air Temperature Sensor not
working normallyReplace
Engine Coolant Temperature Sensor
circuit open or shortedCorrect or replace
Engine Coolant Temperature Sensor
defectiveReplace
Powertrain Control Module defectiveReplace
Trouble in intake or exhaust systemAir Cleaner Filter cloggedReplace filter element
Air duct kinked or flattenedCorrect or replace
TWC defectiveRepair
Ignition failureÐÐÐÐRefer to Hard Start Troubleshooting
Guide
Heat range of spark plug inadequateInstall spark plugs of adequate heat
range
Ignition coil defectiveReplace
6A±14
ENGINE MECHANICAL (6VE1 3.5L)
Abnormal Combustion
ConditionPossible causeCorrection
Trouble in fuel systemFuel pressure control valve defectiveReplace
Fuel filter cloggedReplace
Fuel pump cloggedClean or replace
Fuel tank or fuel pipe cloggedClean or replace
Fuel injector cloggedClean or replace
Fuel pump relay defectiveReplace
Power supply cable for fuel pump
broken or poor connectionsReconnect, correct or replace
Mass Airflow (MAF) Sensor circuit
open or defectiveCorrect or replace
MAF Sensor defectiveReplace
Manifold Absolute Pressure Sensor
circuit open or shortedCorrect or replace
Manifold Absolute Pressure Sensor
defectiveReplace
Engine Coolant Temperature (ECT)
Sensor circuit open or shortedCorrect or replace
ECT Sensor defectiveReplace
Throttle Position Sensor adjustment
incorrectReadjust
Throttle Position Sensor defectiveReplace
Throttle Position Sensor connector
poor connectionsReconnect
Vehicle Speed Sensor cable poor
connections or defectiveCorrect or replace
Vehicle Speed Sensor loosely fixedFix tightly
Vehicle Speed Sensor in wrong
contact or defectiveReplace
Powertrain Control Module cable
poor connections or defectiveCorrect or replace
Trouble in emission control systemHeated Oxygen Sensor circuit openCorrect or replace
Heated Oxygen Sensor defectiveReplace
Signal vacuum hose loosely fitted or
defectiveCorrect or replace
EGR Valve circuit open or shortedCorrect or replace
Exhaust Gas Recirculation Valve
defectiveReplace
ECT Sensor circuit open or shortedCorrect or replace
Canister Purge Valve circuit open or
shortedCorrect or replace
Canister Purge Valve defectiveReplace
ECT Sensor defectiveReplace
Positive Crankcase Ventilation
(PCV) valve and hose cloggedCorrect or replace
Evaporator systemRefer to Section 6E
Trouble in ignition systemÐÐÐÐRefer to ªEngine Lacks Powerº
6A±17
ENGINE MECHANICAL (6VE1 3.5L)
Fuel Consumption Excessive
ConditionPossible causeCorrection
Trouble in fuel systemMixture too rich or too lean due to
trouble in fuel injection systemRefer to ªAbnormal Combustionº
Fuel cut function does not workRefer to ªAbnormal Combustionº
Trouble in ignition systemMisfiring or abnormal combustion
due to trouble in ignition systemRefer to ªHard Startº or ªAbnormal
Combustionº
OthersEngine idle speed too highReset Idle Air Control Valve
Fuel system leakageCorrect or replace
Clutch slippingCorrect
Brake dragCorrect
Selection of transmission gear
incorrectCaution operator of incorrect gear
selection
Excessive Exhaust Gas
Recirculation flow due to trouble in
Exhaust Gas Recirculation systemRefer to ªAbnormal Combustionº
Lubrication Problems
ConditionPossible causeCorrection
Oil pressure too lowWrong oil in useReplace with correct engine oil
Relief valve stickingReplace
Oil pump not operating properlyCorrect or replace
Oil pump strainer cloggedClean or replace strainer
Oil pump wornReplace
Oil pressure gauge defectiveCorrect or replace
Crankshaft bearing or connecting
rod bearing wornReplace
Oil contaminationWrong oil in useReplace with correct engine oil
Oil filter cloggedReplace oil filter
Cylinder head gasket damageReplace gasket
Burned gases leakingReplace piston and piston rings or
cylinder body assembly
Oil not reaching valve systemOil passage in cylinder head or
cylinder body cloggedClean or correct
Engine Oil Pressure Check
1. Check for dirt, gasoline or water in the engine oil.
a. Check the viscosity of the oil.
b. Check the viscosity of the oil.
c. Change the oil if the viscosity is outside the
specified standard.
d. Refer to the ªMaintenance and Lubricationº section
of this manual.
2. Check the engine oil level.
The level should fall somewhere between the ªADDº
and the ªFULLº marks on the oil level dipstick.
If the oil level does not reach the ªADDº mark on the
oil level dipstick, engine oil must be added.3. Remove the oil pressure unit.
4. Install an oil pressure gauge.
5. Start the engine and allow the engine to reach normal
operating temperature (About 80C).
6. Measure the oil pressure.
Oil pressure should be:
392±550 kPa (56.9±80.4 psi) at 3000 rpm.
7. Stop the engine.
8. Remove the oil pressure gauge.
9. Install the oil pressure unit.
10. Start the engine and check for leaks.
6A±18
ENGINE MECHANICAL (6VE1 3.5L)
Malfunction Indicator Lamp
The instrument panel ªCHECK ENGINEº Malfunction In-
dicator Lamp (MIL) illuminates by self diagnostic system
when the system checks the starting of engine, or senses
malfunctions.
Condition
Possible causeCorrection
ªCHECK ENGINEº MIL does not
illuminate at the starting of engine
Bulb defectiveReplace
illuminate at the starting of engineMIL circuit openCorrect or replace
Command signal circuit to operate
self diagnostic system shortedCorrect or replace
Powertrain Control Module (PCM)
cable loosely connected,
disconnected or defectiveCorrect or replace
PCM defectiveReplace
ªCHECK ENGINEº MIL illuminates,
and stays onDeterioration of heated oxygen
sensor internal elementReplace
Heated oxygen sensor connector
terminal improper contactReconnect properly
Heated oxygen sensor lead wire
shortedCorrect
Heated oxygen sensor circuit openCorrect or replace
Deterioration of engine coolant
temperature sensor internal elementReplace
Engine coolant temperature sensor
connector terminal improper contactReconnect properly
Engine coolant temperature sensor
lead wire shortedCorrect
Engine coolant temperature sensor
circuit openCorrect or replace
Throttle position sensor open or
shorted circuitsCorrect or replace
Deterioration of crankshaft position
sensorReplace
Crankshaft position sensor circuit
open or shortedCorrect or replace
Vehicle speed sensor circuit openCorrect or replace
Manifold absolute pressure sensor
circuit open or shortedCorrect or replace
Intake air temperature sensor circuit
open or shortedCorrect or replace
Fuel injector circuit open or shortedCorrect or replace
PCM driver transistor defectiveReplace PCM
Malfunctioning of PCM RAM
(Random Access Memory) or ROM
(Read Only Memory)Replace PCM