
6A-10 ENGINE MECHANICAL (6VE1 3.5L)
Engine Lacks Power
Symptom Possible Cause Action
Trouble in fuel system Fuel Pressure Control Valve not
working normally Replace
Fuel injector clogged Clean or replace
Fuel pipe clogged Clean
Fuel filter clogged or fouled Replace
Fuel pump drive circuit not working
normally Correct or replace
Fuel tank not sufficiently breathing
due to clogged Evaporative Emission
Control System circuit Clean or replace
Water in fuel system Clean
Inferior quality fuel in fuel system Use fuel of specified octane rating
Engine Control Module supplied poor
voltage Correct circuit
Throttle Position Sensor cable broken
or poor connections Correct or replace
Throttle Position Sensor defective Replace
Mass Airflow Sensor not working
normally Replace
Manifold Absolute Pressure Sensor
not working normally Replace
Intake Air Temperature Sensor not
working normally Replace
Engine Coolant Temperature Sensor
circuit open or shorted Correct or replace
Engine Coolant Temperature Sensor
defective Replace
Engine Control Module defective Replace
Trouble in intake or exhaust system Air Cleaner Filter clogged Replace filter element
Air duct kinked or flattened Correct or replace
Exhaust system clogged Correct or replace
Ignition failure ———— Refer to Hard Start Troubleshooting
Guide
Heat range of spark plug inadequateInstall spark plugs of adequate heat
range
Ignition coil defective Replace

ENGINE MECHANICAL (6VE1 3.5L) 6A-15
Abnormal Combustion
Symptom Possible Cause Action
Trouble in fuel system Fuel pressure control valve defectiveReplace
Fuel filter clogged Replace
Fuel pump clogged Clean or replace
Fuel tank or fuel pipe clogged Clean or replace
Fuel injector clogged Clean or replace
Fuel pump relay defective Replace
Power supply cable for fuel pump
broken or poor connections Reconnect, correct or replace
Mass Airflow (MAF) Sensor circuit
open or defective Correct or replace
MAF Sensor defective Replace
Engine Coolant Temperature (ECT)
Sensor circuit open or shorted Correct or replace
ECT Sensor defective Replace
Throttle Position Sensor adjustment
incorrect Readjust
Throttle Position Sensor defective Replace
Throttle Position Sensor connector
poor connections Reconnect
Vehicle Speed Sensor cable poor
connections or defective Correct or replace
Vehicle Speed Sensor loosely fixed Fix tightly
Vehicle Speed Sensor in wrong
contact or defective Replace
Engine Control Module cable poor
connections or defective Correct or replace

6A-20 ENGINE MECHANICAL (6VE1 3.5L)
Malfunction Indicator Lamp
The instrument panel “CHECK ENGINE" Malfunction
Indicator Lamp (MIL) illuminates by self diagnostic
system when the system checks the starting of engine,
or senses malfunctions. ”CHECK ENGINE" MIL does
not illuminate at the starting of engine
Symptom Possible Cause Action
“CHECK ENGINE" MIL does not
illuminate at the starting of engine Bulb defective Replace
MIL circuit open Correct or replace
Command signal circuit to operate
self diagnostic system shorted Correct or replace
Engine Control Module (ECM) cable
loosely connected, disconnected or
defective Correct or replace
ECM defective Replace
“CHECK ENGINE" MIL illuminates,
and stays on Deterioration of heated oxygen
sensor internal element Replace
Heated oxygen sensor connector
terminal improper contact Reconnect properly
Heated oxygen sensor lead wire
shorted Correct
Heated oxygen sensor circuit open Correct or replace
Deterioration of engine coolant
temperature sensor internal element Replace
Engine coolant temperature sensor
connector terminal improper contact Reconnect properly
Engine coolant temperature sensor
lead wire shorted Correct
Engine coolant temperature sensor
circuit open Correct or replace
Throttle position sensor open or
shorted circuits Correct or replace
Deterioration of crankshaft position
sensor Replace
Crankshaft position sensor circuit
open or shorted Correct or replace
Vehicle speed sensor circuit open Correct or replace
Intake air temperature sensor circuit
open or shorted Correct or replace
Fuel injector circuit open or shorted Correct or replace
ECM driver transistor defective Replace ECM
Malfunctioning of ECM RAM
(Random Access Memory) or ROM
(Read Only Memory) Replace ECM

ENGINE MECHANICAL (6VE1 3.5L) 6A-21
Cylinder Head Cover LH
Removal
1. Disconnect battery ground cable.
2. Disconnect positive crankcase ventilation hose.
3. Remove camshaft angle sensor connector.
4. Remove ground cable fixing bolt on cylinder head
cover.
5. Ignition coil connector and ignition coil.
Disconnect the three connectors from the
ignition coils.
Remove harness bracket bolt on cylinder head
cover.
Remove fixing bolts on ignition coils.
060RW078
Legend
(1) Ignition Coil Connector
(2) Bolt
(3) Ignition Coil Assemblies
6. Remove fixing bolt for fuel injector harness
bracket.
7. Remove eight fixing bolts, then the cylinder head
cover.
010RW001
Installation
1. Install cylinder head cover.
Clean the sealing surface of cylinder head and
cylinder head cover to remove oil and sealing
materials completely.
Apply sealant (TB-1207B or equivalent) of bead
diameter 2-3 mm at eight place of arched area
of camshaft bracket on front and rear sides.
The cylinder head cover must be installed with
in 5 minutes after sealant application to preven
t
hardening of sealant.
Tighten bolts to the specified torque.
Torque : 9 N
m (0.9 kg
m/7 lb ft)
010RW006

ENGINE MECHANICAL (6VE1 3.5L) 6A-23
Cylinder Head Cover RH
Removal
1. Disconnect battery ground cable.
2. Remove air cleaner duct assembly.
3. Disconnect ventilation hose from cylinder head
cover.
4. Disconnect three ignition coil connectors from
ignition coils and remove harness bracket bolts on
cylinder head cover then remove ignition coil fixing
bolts on ignition coils and remove ignition coils.
5. Remove heater pipe fixing bolts from the bracket.
6. Disconnect fuel injector harness connector then
remove fuel injector harness bracket bolt.
7. Remove eight fixing bolts then the cylinder head
cover.
010RW002
Installation
1. Install cylinder head cover.
Clean the sealing surface of cylinder head and
cylinder head cover to remove oil and sealing
materials completely.
Apply sealant (TB-1207B or equivalent) of bead
diameter 2‐3 mm at eight place of arched
area of camshaft bracket on front and rea
r
sides.
The cylinder head cover must be installed
within 5 minutes after sealant application to
prevent premature hardening of sealant.
Tighten bolts to the specified torque.
Torque : 9 N
m (0.9 kg
m/7 lb ft)
014RW019
2. Install exhaust gas recirculation pipe and tighten to
specified torque.
Torque :
Exhaust manifold side: 29 N
m (3.0 kg
m/21 lb ft)
Flare nut: 44 N
m (4.5 kg
m/33 lb ft)
Cylinder head side: 20 N
m (2.0 kg
m/14 lb ft)
3. Tighten fuel injector harness bracket bolts to
specified torque then reconnect fuel injecto
r
harness connector.
Torque : 8 N
m (0.8 kg
m/5.7 lb ft)
4. Install heater pipe bolt to the specified torque.
Torque : 20 N
m (2.0 kg
m/14 lb ft)
5. Connect ignition coil connector and tighten ignition
coil fixing bolts to specified torque.
Torque : 4 N
m (0.4 kg
m/3 lb ft)
6. Connect ventilation hose to cylinder head.
7. Install air cleaner duct assembly.

ENGINE FUEL (6VE1 3.5L) 6C-3
Fuel Metering
The Engine Control Module (ECM) is in complete
control of this fuel delivery system during normal driving
conditions.
The intake manifold function, like that of a diesel, is
used only to let air into the engine. The fuel is injected
by separate injectors that are mounted over the intake
manifold.
The Barometric Pressure (BARO) sensor measures the
changes in the barometric pressure which result from
engine load and speed changes, which the BARO
sensor converts to a voltage output.
This sensor generates the voltage to change
corresponding to the flow of the air drawn into the
engine.
The changing voltage is transformed into an electric
signal and provided to the ECM.
With receipt of the signals sent from the BARO sensor,
Intake Air Temperature sensor and others, the ECM
determines an appropriate fuel injection pulse width
feeding such information to the fuel injector valves to
effect an appropriate air/fuel ratio.
The Multiport Fuel Injection system utilizes an injection
system where the injectors turn on at every crankshaf
t
revolution. The ECM controls the injector on time so
that the correct amount of fuel is metered depending on
driving conditions.
Two interchangeable “O" rings are used on the injecto
r
that must be replaced when the injectors are removed.
The fuel rail is attached to the top of the intake manifold
and supplies fuel to all the injectors.
Fuel is recirculated through the rail continually while the
engine is running. This removes air and vapors from the
fuel as well as keeping the fuel cool during hot weathe
r
operation.
The fuel pressure control valve that is mounted on the
fuel rail maintains a pressure differential across the
injectors under all operating conditions. It is
accomplished by controlling the amount of fuel that is
recirculated back to the fuel tank based on engine
demand.
See Section “Driveability and Emission" for more
information and diagnosis.

ENGINE FUEL (6VE1 3.5L) 6C-5
Fuel Pump Flow Test
If reduction of fuel supply is suspected, perform the
following checks.
1. Make sure that there is fuel in the tank.
2. With the engine running, check the fuel feed pipe
and hose from fuel tank to injector for evidence o
f
leakage. Retighten, if pipe or hose connection is
loose. Also, check pipes and hoses for squashing
or clogging.
3. Insert the hose from fuel feed pipe into a clean
container, and check for fuel pump flow rate.
4. Connect the pump relay terminals (2) with a
jumper wire (1) as shown and start the fuel pump
to measure delivery.
RTW36CSH000201
CAUTION: Never generate sparks when connecting
a jumper wire.
Delivery Delivery
15 seconds 0.38 liters minimum
If the measure value is out of standard, conduct the
pressure test.
Pressure test
For the pressure test to the fuel system, see Section 6E
“Fuel Control System".

6E-2 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Visual/Physical Engine Compartment
Inspection ...................................................... 6E-74
Basic Knowledge of Tools Required............... 6E-71
Serial Data Communications .......................... 6E-71
On-Board Diagnostic (OBD) ........................... 6E-71
Comprehensive Component Monitor
Diagnostic Operation ..................................... 6E-71
The Diagnostic Executive ............................... 6E-72
Verifying Vehicle Repair ................................. 6E-73
Reading Flash Diagnostic Trouble Codes ...... 6E-73
Reading Diagnostic Trouble Codes Using
a Tech 2......................................................... 6E-73
On-Board Diagnosis (Self-Diagnosis)............. 6E-74
Diagnosis with Tech 2 .................................... 6E-75
TYPICAL SCAN DATA & DEFINITIONS
(ENGINE DATA) ............................................... 6E-79
TYPICAL SCAN DATA & DEFINITIONS
(O2 SENSOR DATA)........................................ 6E-81
MISCELLANEOUS TEST .................................. 6E-83
PLOTTING SNAPSHOT GRAPH ...................... 6E-85
Plotting Graph Flow Chart (Plotting graph
after obtaining vehicle information)................ 6E-86
Flow Chart for Snapshot Replay
(Plotting Graph) ............................................. 6E-87
SNAPSHOT DISPLAY WITH TIS2000.............. 6E-88
SERVICE PROGRAMMING SYSTEM (SPS).... 6E-91
HOW TO USE BREAKER BOX ........................ 6E-94
ON-BOARD DIAGNOSTIC (OBD) SYSTEM
CHECK ............................................................. 6E-97
NO CHECK ENGINE LAMP (MIL)..................... 6E-101
CHECK ENGINE LAMP (MIL) "ON" STEADY ... 6E-104
FUEL INJECTOR COIL TEST PROCEDURE
AND FUEL INJECTOR BALANCE
TEST PROCEDURE ......................................... 6E-106
FUEL SYSTEM ELECTRICAL TEST ................ 6E-111
FUEL SYSTEM DIAGNOSIS ............................. 6E-116
A/C SYSTEM CIRCUIT DIAGNOSIS ................ 6E-122
ECM DIAGNOSTIC TROUBLE CODES (DTC) 6E-130
MULTIPLE DTC SETS TROUBLESHOOTING
AIDS ................................................................. 6E-142
DTC P0101 (FLASH CODE 61) MASS
AIR FLOW SENSOR CIRCUIT
RANGE/PERFORMANCE ................................ 6E-146
DTC P0102 (FLASH CODE 61) MASS
AIR FLOW SENSOR CIRCUIT LOW INPUT ... 6E-149
DTC P0103 (FLASH CODE 61) MASS
AIR FLOW SENSOR CIRCUIT HIGH INPUT .. 6E-154
DTC P0112 (FLASH CODE 23) INTAKE AIR
TEMPERATURE (IAT) SENSOR LOW
INPUT ............................................................... 6E-158 DTC P0113 (FLASH CODE 23) INTAKE AIR
TEMPERATURE (IAT) SENSOR HIGH
INPUT ............................................................... 6E-163
DTC P0117 (FLASH CODE 14) ENGINE
COOLANT TEMPERATURER (ECT)
SENSOR LOW INPUT ..................................... 6E-168
DTC P0118 (FLASH CODE 14) ENGINE
COOLANT TEMPERATURER (ECT)
SENSOR HIGH INPUT..................................... 6E-173
DTC P0121 (FLASH CODE 21) THROTTLE
POSITION SENSOR (TPS) CIRCUIT
RANGE/PERFORMANCE ................................ 6E-179
DTC P0122 (FLASH CODE 21) THROTTLE
POSITION SENSOR (TPS) CIRCUIT
LOW INPUT ..................................................... 6E-183
DTC P0123 (FLASH CODE 21) THROTTLE
POSITION SENSOR (TPS) CIRCUIT
HIGH INPUT ..................................................... 6E-188
DTC P0131 (FLASH CODE 15) O2 SENSOR
CIRCUIT LOW VOLTAGE
(BANK 1 SENSOR 1) ....................................... 6E-193
DTC P0151 (FLASH CODE 15) O2 SENSOR
CIRCUIT LOW VOLTAGE
(BANK 2 SENSOR 1) ....................................... 6E-193
DTC P0132 (FLASH CODE 15) O2 SENSOR
CIRCUIT HIGH VOLTAGE
(BANK 1 SENSOR 1) ....................................... 6E-201
DTC P0152 (FLASH CODE 15) O2
SENSOR CIRCUIT HIGH VOLTAGE
(BANK 2 SENSOR 1) ....................................... 6E-201
DTC P0134 (FLASH CODE 15) O2 SENSOR
CIRCUIT NO ACTIVITY DETECTED
(BANK 1 SENSOR 1) ....................................... 6E-207
DTC P0154 (FLASH CODE 15) O2 SENSOR
CIRCUIT NO ACTIVITY
DETECTED (BANK 2 SENSOR 1) ................... 6E-207
DTC P0171 (FLASH CODE 44) O2 SENSOR
SYSTEM TOO LEAN (BANK 1) ....................... 6E-211
DTC P0174 (FLASH CODE 44) O2 SENSOR
SYSTEM TOO LEAN (BANK 2) ....................... 6E-211
DTC P0172 (FLASH CODE 45) O2 SENSOR
SYSTEM TOO RICH (BANK 1) ........................ 6E-216
DTC P0175 (FLASH CODE 45) O2 SENSOR
SYSTEM TOO RICH (BANK 2) ........................ 6E-216
DTC P1171 (FLASH CODE 44) FUEL
SUPPLY SYSTEM LEAN DURING POWER
ENRICHMENT (TYPE A) ................................. 6E-221
DTC P1172 (FLASH CODE 44) FUEL SUPPLY
SYSTEM LEAN DURING POWER
ENRICHMENT (TYPE B) ................................. 6E-221