
ENGINE ELECTRICAL 6D – 3
ON-VEHICLE SERVICE
BATTERY CHARGING
Observe  the  following  safety  precautions  when
charging the battery:
1. Never  attempt  to  charge  the  battery  when  the  fluid
level is below the lower level line on the side of the
battery. In this case, the battery must be replaced.
2. Pay  close  attention  to  the  battery  during  the
charging procedure.
Battery charging should be discontinued or the rate
of  charge  reduced  if  the  battery  feels  hot  to  the
touch.
Battery charging should be discontinued or the rate
of  charge  reduced  if  the  battery  begins  to  gas  or
spew electrolyte from the vent holes.
3. In  order  to  more  easily  view  the  hydrometer  blue
dot  or  ring,  it  may  be  necessary  to  jiggle  or  tilt  the
battery.
4. Battery  temperature  can  have  a  great  effect  on
battery charging capacity.
5. The  sealed  battery  used  on  this  vehicle  may  be
either  quick-charged  or  slow-charged  in  the  same
manner as other batteries.
Whichever method you  decide to use, be sure  that
you  completely  charge  the  battery.  Never  partially
charge the battery.
JUMP STARTING
JUMP STARTING WITH AN AUXILIARY
(BOOSTER) BATTERY
CAUTION:  Never  push  or  tow  the  vehicle  in  an
attempt to start it. Serious damage to the emission
system as well as other vehicle parts will result.
Treat  both  the  discharged  battery  and  the  booster
battery  with  great  care  when  using  jumper  cables.
Carefully follow the jump starting procedure, being
careful at all times to avoid sparking.
WARNING:  Failure  to  carefully  follow  the  jump
starting procedure could result in the following:
1. Serious  personal  injury,  particularly  to  your
eyes.
2. Property  damage  from  a  battery  explosion,
battery acid, or an electrical fire.
3. Damage to the electronic components of one or
both vehicles.
Never expose the battery to an open flame or electrical
spark.  Gas  generated  by  the  battery  may  catch  fire  or
explode.  Remove  any  rings,  watches,  or  other  jewelry
before working around the battery. Protect your eyes by
wearing an approved set of goggles.
Never  allow  battery  fluid  to  come  in  contact  with  your
eyes or skin.
Never allow battery fluid to come in contact with fabrics
or painted surfaces.
Battery fluid is a highly corrosive acid.Should battery fluid come in contact with your eyes,
skin,  fabric,  or  a  painted  surface,  immediately  and
thoroughly rinse the affected area with clean tap water.
Never  allow  metal  tools  or  jumper  cables  to  come  in
contact  with  the  positive  battery  terminal,  or  any  other
metal surface of  the  vehicle. This will protect  against a
short circuit.
Always  keep  batteries  out  of  the  reach  of  young
children.
JUMP STARTING PROCEDURE
1. Set the vehicle parking brake.
If  the  vehicle  is  equipped  with  an  automatic
transmission, place the selector lever in the “PARK”
position.
If  the  vehicle  is  equipped  with  a  manual
transmission place the shift lever in the “NEUTRAL”
position.
Turn “OFF” the ignition.
Turn  “OFF”    all  lights  and  any  other  accessory
requiring electrical power.
2. Look at the built-in hydrometer.
If  the  indication  area  of  the  built-in  hydrometer  is
completely clear, do not try to jump start.
3. Attach  the  end  of  one  jumper  cable  to  the  positive
terminal of the booster battery.
Attach  the  other  end  of  the  same  cable  to  the
positive terminal of the discharged battery.
Do not allow the vehicles to touch each other.
This  will  cause  a  ground  connection,  effectively
neutralizing the charging procedure.
Be sure that the booster battery has a 12 volt rating.
4. Attach  one  end  of  the  remaining  cable  to  the
negative terminal of the booster battery.
Attach  the  other  end  of  the  same  cable  to  a  solid
engine  ground  (such  as  the  A/C  compressor
bracket  or  the  generator  mounting  bracket)  of  the
vehicle with the discharged battery.
This  ground  connection  must  be  at  least  450  mm
(18 in) from the battery of the vehicle whose battery
is being charged.
WARNING:  Never  attach  the  end  of  the  jumper
cable  directly  to  the  negative  terminal  of  the  dead
battery.
5. Start the engine of the vehicle with the good battery.
Make  sure  that  all  unnecessary  electrical
accessories have been turned “OFF”.
6. Start the engine of the vehicle with the dead battery.
7. To  remove  the  jumper  cables,  follow  the  above
directions in the reverse order.
Be  sure  to  first  disconnect  the  negative  cable  from
the vehicle with the discharged battery. 

6E–1 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
4JX1–TC 3.0L ENGINE 
DRIVEABILITY AND EMISSIONS
CONTENTS
Specification 6E–7. . . . . . . . . . . . . . . . . . . . . . . . . . 
Tightening Specifications 6E–7. . . . . . . . . . . . . . . 
Diagrams and Schematics 6E–8. . . . . . . . . . . . . . . . 
ECM Wiring Diagram (1 of 6) 6E–8. . . . . . . . . . . . 
ECM Wiring Diagram (2 of 6) 6E–9. . . . . . . . . . . . 
ECM Wiring Diagram (3 of 6) 6E–10. . . . . . . . . . . . 
ECM Wiring Diagram (4 of 6) 6E–11. . . . . . . . . . . . 
ECM Wiring Diagram (5 of 6) 6E–12. . . . . . . . . . . . 
ECM Wiring Diagram (6 of 6) 6E–13. . . . . . . . . . . . 
ECM Pinouts 6E–14. . . . . . . . . . . . . . . . . . . . . . . . . . . 
ECM Pinout Table, 32-Way Connector – J1
 RED – Upper 6E–14. . . . . . . . . . . . . . . . . . . . . . . . . 
ECM Pinout Table, 32-Way Connector – J1
 RED – Lower 6E–15. . . . . . . . . . . . . . . . . . . . . . . . . 
ECM Pinout Table, 32-Way Connector – J2
 BLUE – Upper 6E–16. . . . . . . . . . . . . . . . . . . . . . . . 
ECM Pinout Table, 32-Way Connector – J2
 BLUE – Lower 6E–17. . . . . . . . . . . . . . . . . . . . . . . . 
ECM Pinout Table,  5-Way Connector – J3 6E–18
Component Locator 6E–19. . . . . . . . . . . . . . . . . . . . . 
Sensors and Miscellaneous Component
 Locators 6E–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
Abbreviations Charts 6E–23. . . . . . . . . . . . . . . . . . . . 
Diagnosis 6E–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
Strategy-Based Diagnostics 6E–24. . . . . . . . . . . . . 
Strategy-Based Diagnostics 6E–24. . . . . . . . . . . . . 
DTC Stored 6E–24. . . . . . . . . . . . . . . . . . . . . . . . . . . 
No DTC 6E–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
No Matching Symptom 6E–24. . . . . . . . . . . . . . . . . 
Intermittents 6E–24. . . . . . . . . . . . . . . . . . . . . . . . . . 
No Trouble Found 6E–24. . . . . . . . . . . . . . . . . . . . . 
Verifying Vehicle Repair 6E–24. . . . . . . . . . . . . . . . 
General Service Information 6E–25. . . . . . . . . . . . . . 
Serviceability Issues 6E–25. . . . . . . . . . . . . . . . . . . 
Visual/Physical Engine Compartment
 Inspection 6E–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . 
Basic Knowledge of Tools Required 6E–25. . . . . . 
Serial Data Communications 6E–25. . . . . . . . . . . . . . 
Class II Serial Data Communications 6E–25. . . . . 
On-Board Diagnostic (OBD) 6E–25. . . . . . . . . . . . . . 
On-Board Diagnostic Tests 6E–25. . . . . . . . . . . . . 
Comprehensive Component Monitor
 Diagnostic Operation 6E–25. . . . . . . . . . . . . . . . . . 
Common OBD Terms 6E–26. . . . . . . . . . . . . . . . . . 
The Diagnostic Executive 6E–26. . . . . . . . . . . . . . . 
DTC Types 6E–26. . . . . . . . . . . . . . . . . . . . . . . . . . . 
Verifying Vehicle Repair 6E–27. . . . . . . . . . . . . . . . Reading Flash Diagnostic Trouble Codes 6E–27. 
Reading Diagnostic Trouble Codes Using
 a TECH 2 6E–28. . . . . . . . . . . . . . . . . . . . . . . . . . . . 
Tech 2 Scan Tool 6E–29. . . . . . . . . . . . . . . . . . . . . . 
Getting Started 6E–30. . . . . . . . . . . . . . . . . . . . . . . . 
DTC Modes 6E–32. . . . . . . . . . . . . . . . . . . . . . . . . . . 
DTC Information Mode 6E–32. . . . . . . . . . . . . . . . . 
Injector Test 6E–32. . . . . . . . . . . . . . . . . . . . . . . . . . 
EGR Valve Test 6E–32. . . . . . . . . . . . . . . . . . . . . . . 
Rail Pressure Control Valve Test 6E–32. . . . . . . . . 
Injector Balance Test 6E–32. . . . . . . . . . . . . . . . . . . 
Data Programming in Case of ECM Change 6E–32
Rail Pressure Sensor Programming 6E–33. . . . . . 
Injector Group Sign Programming
 (Injector Change) 6E–33. . . . . . . . . . . . . . . . . . . . . 
On-Board Diagnostic (OBD) System Check 6E–35. 
Circuit Description 6E–37. . . . . . . . . . . . . . . . . . . . . 
Diagnostic Aids 6E–37. . . . . . . . . . . . . . . . . . . . . . . . 
Engine Control Module ECM Diagnosis 6E–39. . . . 
Multiple ECM Information Sensor DTCS Set 6E–39
Circuit Description 6E–39. . . . . . . . . . . . . . . . . . . . . 
Diagnostic Aids 6E–39. . . . . . . . . . . . . . . . . . . . . . . . 
EGR (Exhaust Gas Recirculation) Diagnosis 6E–41
Tech 2 Data Definitions and Ranges 6E–41. . . . . . . 
Typical Scan Data Values 6E–41. . . . . . . . . . . . . . . . 
Test Conditions 6E–41. . . . . . . . . . . . . . . . . . . . . . . . 
4JX1-TC Engine (Automatic and Manual
 Transmission) 6E–42. . . . . . . . . . . . . . . . . . . . . . . . 
No Malfunction Indicator Lamp (MIL) 6E–44. . . . . . . 
Circuit Description 6E–44. . . . . . . . . . . . . . . . . . . . . 
Diagnostic Aids 6E–44. . . . . . . . . . . . . . . . . . . . . . . . 
Malfunction Indicator Lamp (MIL) “ON”
 Steady 6E–47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
Circuit description 6E–47. . . . . . . . . . . . . . . . . . . . . 
Diagnostic Aids 6E–47. . . . . . . . . . . . . . . . . . . . . . . . 
Engine Cranks But Will Not Run 6E–49. . . . . . . . . . . 
Circuit Description 6E–49. . . . . . . . . . . . . . . . . . . . . 
Diagnostic Aids 6E–49. . . . . . . . . . . . . . . . . . . . . . . . 
Exhaust Gas Recirculation (EGR) System
 Check 6E–52. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
Circuit Description 6E–52. . . . . . . . . . . . . . . . . . . . . 
ECM Diagnostic Trouble Codes 6E–54. . . . . . . . . . . 
ECM Diagnostic Trouble Codes 6E–54. . . . . . . . . 
Diagnostic Trouble Code (DTC) P0107
 (Flash DTC 34) 
MAP Sensor Circuit Low Voltage 6E–56. . . . . . . . . .  

6E–6
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Removal Procedure 6E–212. . . . . . . . . . . . . . . . . . . . 
Installation Procedure 6E–212. . . . . . . . . . . . . . . . . . 
Fuel Filter Cap 6E–213. . . . . . . . . . . . . . . . . . . . . . . . . . 
General Description 6E–213. . . . . . . . . . . . . . . . . . . . 
Inspection Procedure 6E–213. . . . . . . . . . . . . . . . . . 
Fuel Filter 6E–213. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
Removal and Installation Procedure 6E–213. . . . . . 
Fuel Gauge Unit 6E–213. . . . . . . . . . . . . . . . . . . . . . . . 
Removal Procedure 6E–213. . . . . . . . . . . . . . . . . . . . 
Installation Procedure 6E–214. . . . . . . . . . . . . . . . . . 
Fuel Injectors 6E–214. . . . . . . . . . . . . . . . . . . . . . . . . . . 
Removal and Installation Procedure 6E–214. . . . . . 
Fuel Temperature Sensor 6E–214. . . . . . . . . . . . . . . . 
Removal Procedure 6E–214. . . . . . . . . . . . . . . . . . . . 
Installation Procedure 6E–215. . . . . . . . . . . . . . . . . . 
Rail Pressure (RP) Sensor 6E–216. . . . . . . . . . . . . . . 
Removal Procedure 6E–216. . . . . . . . . . . . . . . . . . . . 
Installation Procedure 6E–216. . . . . . . . . . . . . . . . . . 
Fuel Tank 6E–216. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
Removal Procedure 6E–216. . . . . . . . . . . . . . . . . . . . 
Throttle Body (TB) 6E–217. . . . . . . . . . . . . . . . . . . . . . . 
Removal Procedure 6E–217. . . . . . . . . . . . . . . . . . . . 
Installation Procedure 6E–217. . . . . . . . . . . . . . . . . . 
Air Conditioning (A/C) Relay 6E–217. . . . . . . . . . . . . . 
Removal Procedure 6E–217. . . . . . . . . . . . . . . . . . . . 
Installation Procedure 6E–217. . . . . . . . . . . . . . . . . . 
Exhaust Gas Recirculation (EGR) Vacuum
 Switch Valve (VSV) 6E–217. . . . . . . . . . . . . . . . . . . . . 
Removal Procedure 6E–217. . . . . . . . . . . . . . . . . . . . 
Installation Procedure 6E–218. . . . . . . . . . . . . . . . . . 
Electronic Vacuum Regurating Valve (EVRV) 6E–219
Removal Procedure 6E–219. . . . . . . . . . . . . . . . . . . . 
Installation Procedure 6E–220. . . . . . . . . . . . . . . . . . 
Wiring and Connectors 6E–220. . . . . . . . . . . . . . . . . . . 
Wiring Harness Service 6E–220. . . . . . . . . . . . . . . . 
Connectors and Terminals 6E–220. . . . . . . . . . . . . . 
Wire Harness Repair: Twisted Shielded
 Cable 6E–220. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
Removal Procedure 6E–220. . . . . . . . . . . . . . . . . . . . 
Installation Procedure 6E–221. . . . . . . . . . . . . . . . . . 
Twisted Leads 6E–221. . . . . . . . . . . . . . . . . . . . . . . . . . 
Removal Procedure 6E–221. . . . . . . . . . . . . . . . . . . . 
Installation Procedure 6E–222. . . . . . . . . . . . . . . . . . 
Weather-Pack Connector 6E–223. . . . . . . . . . . . . . . . . 
Tools Required 6E–223. . . . . . . . . . . . . . . . . . . . . . . . 
Removal Procedure 6E–223. . . . . . . . . . . . . . . . . . . . Installation Procedure 6E–223. . . . . . . . . . . . . . . . . . 
Com-Pack III 6E–224. . . . . . . . . . . . . . . . . . . . . . . . . . . 
General Information 6E–224. . . . . . . . . . . . . . . . . . . . 
Metri-Pack 6E–224. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
Tools Required 6E–224. . . . . . . . . . . . . . . . . . . . . . . . 
Removal Procedure 6E–224
. . . . . . . . . . . . . . . . . . . . 
Installation Procedure 6E–224. . . . . . . . . . . . . . . . . . 
General Description 
(ECM and Sensors) 6E–225. . . . . . . . . . . . . . . . . . . . . 
57X Reference ECM Input 6E–225. . . . . . . . . . . . . . 
A/C Request Signal 6E–225. . . . . . . . . . . . . . . . . . . . 
Crankshaft Position (CKP) Sensor 6E–225. . . . . . . 
Camshaft Position (CMP) Sensor and
 Signal 6E–225. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
Engine Coolant Temperature (ECT) Sensor 6E–225
Electrically Erasable Programmable Read
 Only Memory (EEPROM) 6E–225. . . . . . . . . . . . . . 
Intake Air Temperature (IAT) Sensor 6E–225. . . . . 
Manifold Absolute Pressure (MAP) Sensor 6E–226
Engine Control Module (ECM) 6E–226. . . . . . . . . . . 
ECM Function 6E–226. . . . . . . . . . . . . . . . . . . . . . . . . 
ECM Components 6E–226. . . . . . . . . . . . . . . . . . . . . 
ECM Voltage Description 6E–226. . . . . . . . . . . . . . . 
ECM Input/Outputs 6E–226. . . . . . . . . . . . . . . . . . . . 
ECM Service Precautions 6E–227. . . . . . . . . . . . . . 
Intake Throttle Position (ITP) Sensor 6E–227. . . . . 
Transmission Range Switch 6E–227. . . . . . . . . . . . . 
Accelerator Position Sensor (AP) 6E–227. . . . . . . . 
Aftermarket Electrical and Vacuum
 Equipment 6E–227. . . . . . . . . . . . . . . . . . . . . . . . . . . 
Electrostatic Discharge Damage 6E–227. . . . . . . . . 
General Description (Air Induction) 6E–228. . . . . . . . 
Air Induction System 6E–228. . . . . . . . . . . . . . . . . . . 
General Description (Fuel Metering) 6E–228. . . . . . . 
Deceleration Mode 6E–228. . . . . . . . . . . . . . . . . . . . 
Fuel Injector 6E–228. . . . . . . . . . . . . . . . . . . . . . . . . . 
Fuel Metering System Components 6E–228. . . . . . 
A/C Clutch Diagnosis 6E–228. . . . . . . . . . . . . . . . . . . . 
A/C Request Signal 6E–228. . . . . . . . . . . . . . . . . . . . 
General Description Exhaust Gas
 Recirculation (EGR) System 6E–228. . . . . . . . . . . . . 
EGR Purpose 6E–228. . . . . . . . . . . . . . . . . . . . . . . . . 
Fuse and Relay Panel
 (Underhood Electrical Center) RHD 6E–229. . . . . . . 
Fuse and Relay Panel
 (Underhood Electrical Center) LHD 6E–230. . . . . . .  

6E–23 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Abbreviations Charts
List of abbreviations which may be used in this section.
Abbreviations
Te r mAbbreviationsTe r m
A/CAir ConditionerBLKBlack
A/TAutomatic TransmissionBLUBlue
ACCAccessoryBRNBrown
APAccel PositionGRNGreen
ASMAssemblyGRYGray
CKPCrank PositionLT   B L ULight Blue
CMPCam PositionLT   G R NLight Green
DLCData Link ConnectorORNOrange
DTCDiagnosis Trouble CodePNKPink
DVMDigital Volt MeterREDRed
ECMEngine Control ModuleVIOViolet
ECTEngine Coolant TemperatureWHTWhite
EGRExhaust Gas RecircurationYELYe l l o w
EVRVElectric Vacuum Regulating Valve
EXHExhaust
FTFuel Temperature
IATIntake Air Temperature
IGIgnition
ITPIntake Throttle Position
M/TManual Transmission
MAPManifold Absolute Pressure
MILMulfunction Indicator Lamp
OBDOn-Board Diagnostic
OTOil Temperature
QOSQuick on Start System
QWSQuick Warming-Up System
RPRail Pressure
RPCVRail Pressure Control Valve
SRSSupplemental Restraint System
STStart
SWSwitch
TEMPTemperature
TODTorque on Demand
VSSVehicle Speed Sensor
VSVVacuum Switching Valve
HEUIHydraulically Actuated Electronically Controlled Unit
InjectorInjector 

6E–41 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
EGR (Exhaust Gas Recirculation)
Diagnosis
A  diagnosis  of  the  EGR  system  is  covered  by  DTC
P1403.
EGR VSV circuit diagnosis is covered by DTC P1404.
EGR  pressure sensor  diagnosis  is  covered  by  DTC
P405 and/or P406.
EGR  EVRV  circuit  diagnosis  is  covered  by  DTC
P1405. Refer to the DTC charts.
Tech 2 Data Definitions and Ranges
A/C CLUTCH–Tech 2 Displays ON or OFF–
Indicates  whether  the  A/C  has  commanded  the  A/C
clutch ON.
MAP kPa — Tech 2 Range 10-105 kPa/0.00-5.00
Vo l t s   —
The  manifold  absolute  pressure  reading  is  determined
from the MAP sensor signal monitored during key up and
wide  open  throttle  (WOT)  conditions.    The  manifold
absolute  pressure  is  used  to  compensate  for  altitude
differences  and  is  normally  displayed  around  “61-104”
depending on altitude and manifold absolute pressure.
CMP ACT. COUNTER –Cam Position
DESIRED IDLE — Tech 2 Range 0-3187 RPM —
The idle speed that the ECM is commanding.  The ECM
will compensate for various engine loads based on engine
coolant temperature,  to keep the engine at the desired
speed.
ECT — (Engine Coolant Temperature) Tech 2
Range –40
C to 151C (–40F to 304F) —
The engine coolant temperature (ECT) is mounted in the
coolant  stream  and  sends  engine  temperature
information to the ECM.  The ECM applies 5 volts to the
ECT  sensor  circuit.    The  sensor  is  a  thermistor  which
changes  internal  resistance  as  temperature  changes.
When  the  sensor  is  cold  (high  resistance),  the  ECM
monitors a high signal voltage and interprets that as a cold
engine.    As  the  sensor  warms  (decreasing  resistance),
the voltage signal will decrease and the ECM will interpret
the lower voltage as a warm engine.
ENGINE RUN TIME — Tech 2 Range
00:00:00-99:99:99 Hrs:Min:Sec —
Indicates the time elapsed since the engine was started.
If the engine is stopped, engine run time will be reset to
00:00:00.
ENGINE SPEED — Range 0-9999 RPM —
Engine  speed  is  computed  by  the  ECM  from  the  57X
reference  input.    It  should  remain  close  to  desired  idle
under various engine loads with engine idling.Air Intake Valve meter POSITION — Tech 2 Range
0-100 % —
IAT (INTAKE AIR TEMPERATURE)— Tech 2 Range
–40
C to 151C (–40F to 304F) —
The  ECM  converts  the  resistance  of  the  intake  air
temperature  sensor  to  degrees.    Intake  air  temperature
(IAT) is used by the ECM to adjust fuel delivery and spark
timing according to incoming air density.
MAP — Tech 2 Range 10-105 kPa (0.00-4.97 Volts)—
The manifold absolute pressure (MAP) sensor measures
the change in the boost pressure.
MIL — Tech 2 Displays ON or OFF —
Indicates the ECM commanded state of the malfunction
indicator lamp.
AP — Tech 2 Range 0%-100% —
AP (Accelerator position)  angle is computed by the ECM
from  the  AP  sensor  voltage.    AP  angle  should  display
“0%” at idle and “100%” at wide open throttle.
AP SENSOR — Tech 2 Range 0.00-5.00 Volts —
The  voltage  being  monitored  by  the  ECM  on  the  AP
sensor signal circuit.
VEHICLE SPEED—Tech 2 Range 0-255 km/h (0-155
mph)–
The vehicle  speed  sensor signal  is  converted into km/h
and mph for display.
Typical Scan Data Values
Use  the  Typical  Scan  Data  Values  Table  only  after  the
On-Board  Diagnostic  System  Check  has  been
completed,  no  DTC(s)  were  noted,  and  you  have
determined that the on-board diagnostics are functioning
properly.  Tech 2 values from a properly-running engine
may  be  used  for  comparison  with  the  engine  you  are
diagnosing.    The  typical  scan  data  values  represent
values that would be seen on a normally-running engine.
NOTE: A Tech 2 that displays faulty data should not be
used, and the problem should be reported to the Tech 2
manufacturer.    Use  of  a  faulty  Tech  2  can  result  in
misdiagnosis and unnecessary replacement of parts.
Only  the  parameters  listed  below  are  referred  to  in  this
service  manual  for  use  in  diagnosis.    For  further
information on using the Tech 2 to diagnose the ECM and
related sensors, refer to the applicable reference section
listed  below.    If  all  values  are  within  the  typical  range
described  below,  refer  to  the 
Symptoms  section  for
diagnosis.
Test Conditions
Engine running, lower radiator hose hot, transmission in
park or neutral, accessaries off, brake not applied and air
conditioning off. 

6E–50
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Engine Cranks But Will Not Run
StepNo Ye s Va l u e ( s ) Action
10Refer to Engine Mechanical Diagnosis to diagnose the
following conditions:
Faulty camshaft drive belts
Leaking or sticky valves or rings
Excessive valve deposits
Weak valve springs
Incorrect valve timing
Leaking head gasket
Is the action complete?
—Verify repairGo to Step 11
11Observe the “Engine Speed” data display on the Tech 2
while cranking the engine.
Is the engine RPM indicated?  (If the Tech 2 is normally
powered  from  the  cigarette  lighter  socket,  and  if  the
Tech 2 display goes blank while cranking the engine, it
will be necessary to power the Tech 2 directly from the
vehicle battery.)
—Go to Step 12Go to Step 17
121. At  the  ECM  (female)  side  of  the  connector
mentioned in step, connect a test light between the
ignition  +  terminal  and  one  of  the  injector  driver
circuits at the same connector.
2. Ignition “ON.”
3. Observe the test light, and repeat the test for each
injector driver circuit by oscilloscope.
Did the  test  light  stay on when  checking  any of the  4
injector driver circuits?
—Go to Step 13Go to Step 15
131. Ignition “OFF,” disconnect the ECM.
2. Ignition “ON,” observe the test light.
Is the test light “ON?”
—Go to Step 14Go to Step 16
14Locate and repair the short to ground in the injector
driver circuit.
Is the action complete?
—Verify repair—
15Check for an open injector driver circuit.
Was a problem found?
—Verify repairGo to Step 16
16Replace the ECM (Refer to the Data Programming in
Case of ECM change).
Is the action complete?
—Verify repair—
171. Raise the vehicle and disconnect the CKP sensor
harness.
2. Ignition “ON.”
3. With  a  test  light  to  ground,  probe  the  harness
ignition feed terminal.
Did the light illuminate?
—Go to Step 19Go to Step 18
18Check the  ignition  feed  wire between  the  sensor  and
the ECM for a short to ground or open circuit.
Is the action complete?
—Verify repair— 

6E–52
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Exhaust Gas Recirculation (EGR) System Check
060RW135
Circuit Description
Introducing  exhaust  gas  into  the  combustion  chamber
lowers  combustion  temperatures  and  reduces  the
formation of oxides of nitrogen (NOx) in the exhaust gas.
Lower combustion temperatures also prevent detonation.
Diagnostic Aids
The EGR valve chart is a check of the EGR system.  An
EGR pintle constantly in the closed position could cause
detonation  and  high  emissions  of  NOx.    An  EGR  pintle
constantly in the open position would cause a rough idle. 

6E–178
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Hard Start Symptom
StepNo Ye s Va l u e ( s ) Action
121. Check the battery voltage.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 13
131. Check  for  the  following  engine  mechanical
problems (Refer to 
Engine Mechanical):
Low compression
Leaking cylinder head gaskets
Worn or incorrect camshaft
Camshaft drive belt slipped or stripped
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 14
141. Review all diagnostic procedures within this table.
2. If  all  procedures  have  been  completed  and  no
malfunctions  have  been  found,  review/inspect  the
following:
Visual/physical inspection
Tech–2 data
Freeze Frame data/Failure Records buffer
All  electrical  connections  within  a  suspected
circuit and/or system.
3. If a problem is found, repair as necessary.
Was a problem found?
—Verify repair
Contact
Te c h n i c a l
Assistance