2002 ISUZU AXIOM heater

6E±1
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
AXIOM
ENGINE
6VE1 3.5L ENGINE
DRIVEABILITY AND EMISSIONS
CONTENTS
Specifications 6E±6. . . . . . . . . . . . . . . . . . . . . . . . . . .
Tightening Specifications 6E±6. . . . . . . . . . . . . . .
Diagrams and Schematics 6E±7. . . . . . . . . . . . . . . .
PCM Wiring Diagram (1 of 7) 6E±7. . . . . . . . . . . .
PCM Wiring Diagram (2 of 7) 6E±8. . . . . . . . . . . .
PCM Wiring Diagram (3 of 7) 6E±9. . . . . . . . . . . .
PCM Wiring Diagram (4 of 7) 6E±10. . . . . . . . . . . .
PCM Wiring Diagram (5 of 7) 6E±11. . . . . . . . . . . .
PCM Wiring Diagram (6 of 7) 6E±12. . . . . . . . . . . .
PCM Wiring Diagram (7 of 7) 6E±13. . . . . . . . . . . .
PCM Pinouts 6E±14. . . . . . . . . . . . . . . . . . . . . . . . . . .
PCM Pinout Table, 80-Way Blue Connector
± Row ªF1 ~ 20º 6E±14. . . . . . . . . . . . . . . . . . . . . .
PCM Pinout Table, 80-Way Blue Connector
± Row ªF20 ~ 40º 6E±15. . . . . . . . . . . . . . . . . . . . .
PCM Pinout Table, 80-Way Blue Connector
± Row ªF41 ~ 60º 6E±16. . . . . . . . . . . . . . . . . . . . .
PCM Pinout Table, 80-Way Blue Connector
± Row ªF61 ~ 80º 6E±17. . . . . . . . . . . . . . . . . . . . .
PCM Pinout Table, 80-Way Red Connector
± Row ªS1 ~ 20º 6E±19. . . . . . . . . . . . . . . . . . . . . .
PCM Pinout Table, 80-Way Red Connector
± Row ªS21 ~ 40º 6E±21. . . . . . . . . . . . . . . . . . . . .
PCM Pinout Table, 80-Way Red Connector
± Row ªS41 ~ 60º 6E±23. . . . . . . . . . . . . . . . . . . . .
PCM Pinout Table, 80-Way Red Connector
± Row ªS61 ~ 80º 6E±25. . . . . . . . . . . . . . . . . . . . .
Component Locators 6E±27. . . . . . . . . . . . . . . . . . .
Undercarriage Component Locator 6E±29. . . . . .
Fuse and Relay Panel (Underhood
Electrical Center) 6E±30. . . . . . . . . . . . . . . . . . . . .
Sensors and Miscellaneous Component
Locators 6E±31. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Diagnosis 6E±33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Strategy-Based Diagnostics 6E±33. . . . . . . . . . . . .
DTC Stored 6E±33. . . . . . . . . . . . . . . . . . . . . . . . . . .
No DTC 6E±33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
No Matching Symptom 6E±33. . . . . . . . . . . . . . . . .
Intermittents 6E±33. . . . . . . . . . . . . . . . . . . . . . . . . .
No Trouble Found 6E±33. . . . . . . . . . . . . . . . . . . . .
Verifying Vehicle Repair 6E±33. . . . . . . . . . . . . . . .
General Service Information 6E±33. . . . . . . . . . . . . .
OBD II Serviceablity Issues 6E±33. . . . . . . . . . . . .
Emissions Control Information Label 6E±34. . . . .
Visual / Physical Engine Compartment
Inspection 6E±34. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Basic Knowledge of Tools Required 6E±35. . . . . .
Serial Data Communications 6E±35. . . . . . . . . . . . . . Class 2 Serial Data Communications 6E±35. . . . .
On-Board Diagnostic (OBD II) 6E±35. . . . . . . . . . . . .
On-Board Diagnostic Tests 6E±35. . . . . . . . . . . . .
Comprehensive Component Monitor
Diagnostic Operation 6E±35. . . . . . . . . . . . . . . . . .
System Status and Drive Cycle for
Satisfying Federal Inspection/Maintenance
(I/M 240) Regulations 6E±36. . . . . . . . . . . . . . . . . .
Common OBD II Terms 6E±36. . . . . . . . . . . . . . . . .
The Diagnostic Executive 6E±36. . . . . . . . . . . . . . .
DTC Types 6E±37. . . . . . . . . . . . . . . . . . . . . . . . . . .
Decimal/Binary/Hexadecimal Conversions 6E±39
Verifying Vehicle Repair 6E±39. . . . . . . . . . . . . . . .
Reading Diagnostic Trouble Codes Using
The Tech 2 Scan Tool 6E±39. . . . . . . . . . . . . . . . .
Tech 2 6E±40. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tech 2 Features 6E±41. . . . . . . . . . . . . . . . . . . . . . .
Getting Started 6E±41. . . . . . . . . . . . . . . . . . . . . . . .
Operating Procedure (For Example) 6E±42. . . . .
DTC Modes 6E±43. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC Information Mode 6E±43. . . . . . . . . . . . . . . . .
Miscellaneous Test 6E±44. . . . . . . . . . . . . . . . . . . .
Lamps Test 6E±44. . . . . . . . . . . . . . . . . . . . . . . . . . .
Relays Test 6E±46. . . . . . . . . . . . . . . . . . . . . . . . . . .
EVAP Test 6E±47. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel System Test 6E±48. . . . . . . . . . . . . . . . . . . . . .
Instruments Test 6E±50. . . . . . . . . . . . . . . . . . . . . . .
EGR Control Test 6E±52. . . . . . . . . . . . . . . . . . . . . .
Variable Intake Manifold Solenoid Test 6E±52. . .
Injector Balance Test 6E±54. . . . . . . . . . . . . . . . . . .
Plotting Snapshot Graph 6E±54. . . . . . . . . . . . . . . . .
Plotting Graph Flow Chart (Plotting graph
after obtaining vehicle information) 6E±55. . . . . .
Flow Chart for Snapshot Replay (Plotting
Graph) 6E±56. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Primary System-Based Diagnostic 6E±57. . . . . . . . .
Primary System-Based Diagnostic 6E±57. . . . . . .
Fuel Control Heated Oxygen Sensor 6E±57. . . . .
HO2S Heater 6E±57. . . . . . . . . . . . . . . . . . . . . . . . .
Catalyst Monitor Heated Oxygen Sensors
and Diagnostic Operation 6E±57. . . . . . . . . . . . . .
Misfire Monitor Diagnostic Operation 6E±58. . . . . . .
Misfire Monitor Diagnostic Operation 6E±58. . . . .
Misfire Counters 6E±58. . . . . . . . . . . . . . . . . . . . . . .

6E±3
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0135 HO2S Heater Circuit
Bank 1 Sensor 1 6E±179. . . . . . . . . . . . . . . . . . . . . . . .
DTC P0137 HO2S Circuit Low Voltage
Bank 1 Sensor 2 6E±182. . . . . . . . . . . . . . . . . . . . . . . .
DTC P0138 HO2S Circuit High Voltage
Bank 1 Sensor 2 6E±185. . . . . . . . . . . . . . . . . . . . . . . .
DTC P0140 HO2S Circuit Insufficient Activity
Bank 1 Sensor 2 6E±188. . . . . . . . . . . . . . . . . . . . . . . .
DTC P0141 HO2S Heater Circuit
Bank 1 Sensor 2 6E±191. . . . . . . . . . . . . . . . . . . . . . . .
DTC P0151 HO2S Circuit Low Voltage
Bank 2 Sensor 1 6E±194. . . . . . . . . . . . . . . . . . . . . . . .
DTC P0152 HO2S Circuit High Voltage
Bank 2 Sensor 1 6E±197. . . . . . . . . . . . . . . . . . . . . . . .
DTC P0153 HO2S Slow Response
Bank 2 Sensor 1 6E±200. . . . . . . . . . . . . . . . . . . . . . . .
DTC P0154 HO2S Circuit Insufficient Activity
Bank 2 Sensor 1 6E±204. . . . . . . . . . . . . . . . . . . . . . . .
DTC P0155 HO2S Heater Circuit Open
Bank 2 Sensor 1 6E±207. . . . . . . . . . . . . . . . . . . . . . . .
DTC P0157 HO2S Circuit Low Voltage
Bank 2 Sensor 2 6E±210. . . . . . . . . . . . . . . . . . . . . . . .
DTC P0158 HO2S Circuit High Voltage
Bank 2 Sensor 2 6E±213. . . . . . . . . . . . . . . . . . . . . . . .
DTC P0160 HO2S Circuit Insufficient Activity
Bank 2 Sensor 2 6E±216. . . . . . . . . . . . . . . . . . . . . . . .
DTC P0161 HO2S Heater Circuit
Bank 2 Sensor 2 6E±219. . . . . . . . . . . . . . . . . . . . . . . .
DTC P0171 Fuel Trim System Lean Bank 1 6E±222.
DTC P0172 Fuel Trim System Rich Bank 1 6E±226.
DTC P0174 Fuel Trim System Lean Bank 2 6E±230.
DTC P0175 Fuel Trim System Rich Bank 2 6E±234.
DTC P0201 Injector 1 Control Circuit 6E±238. . . . . .
DTC P0202 Injector 2 Control Circuit 6E±241. . . . . .
DTC P0203 Injector 3 Control Circuit 6E±244. . . . . .
DTC P0204 Injector 4 Control Circuit 6E±247. . . . . .
DTC P0205 Injector 5 Control Circuit 6E±250. . . . . .
DTC P0206 Injector 6 Control Circuit 6E±253. . . . . .
DTC P0300 Engine Misfire Detected 6E±256. . . . . . .
DTC P0301 Cylinder Misfire Detected 6E±260. . . . . .
DTC P0302 Cylinder Misfire Detected 6E±262. . . . . .
DTC P0303 Cylinder Misfire Detected 6E±264. . . . . .
DTC P0304 Cylinder Misfire Detected 6E±266. . . . . .
DTC P0305 Cylinder Misfire Detected 6E±268. . . . . .
DTC P0306 Cylinder Misfire Detected 6E±270. . . . . .
DTC P0325 ION Sensing Module/ION
Sensing Knock Intensity Circuit Fault 6E±272. . . . . .
DTC P0336 58X Reference Signal Circuit 6E±275. .
DTC P0337 CKP Sensor Circuit Low
Frequency 6E±278. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0351 Ignition 1 Control Circuit 6E±281. . . . . . .
DTC P0352 Ignition 2 Control Circuit 6E±284. . . . . . .
DTC P0353 Ignition 3 Control Circuit 6E±287. . . . . . .
DTC P0354 Ignition 4 Control Circuit 6E±290. . . . . . .
DTC P0355 Ignition 5 Control Circuit 6E±293. . . . . . . DTC P0356 Ignition 6 Control Circuit 6E±296. . . . . . .
DTC P0401 EGR Flow Insufficient 6E±299. . . . . . . . .
DTC P0402 EGR Pintle Crank Error 6E±302. . . . . . .
DTC P0404 EGR Open Stuck 6E±304. . . . . . . . . . . . .
DTC P0405 EGR Low Voltage 6E±306. . . . . . . . . . . .
DTC P0406 EGR High Voltage 6E±309. . . . . . . . . . .
DTC P0420 TWC System Low Efficiency
Bank 1 6E±312. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0430 TWC System Low Efficiency
Bank 2 6E±315. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0440 EVAP System 6E±318. . . . . . . . . . . . . . . .
DTC P0442 EVAP System Small Leak
Detected 6E±321. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0444 EVAP Purge Control Circuit
Open 6E±324. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0445 EVAP Purge Control Circuit
Short 6E±326. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0446 EVAP Canister Vent Control
Malfunction 6E±328. . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0447 EVAP Vent Solenoid Circuit
Open 6E±331. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0448 EVAP Vent solenoid Circuit
Short 6E±333. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0452 Fuel Tank Pressure Sensor
(Vapor Pressure Sensor) Low Voltage 6E±335. . . . .
DTC P0453 Fuel Tank Pressure Sensor
(Vapor Pressure Sensor) High Voltage 6E±338. . . . .
DTC P0456 EVAP Very Small Leak 6E±341. . . . . . .
DTC P0461 Fuel Level Sensor Performance 6E±344
DTC P0462 Fuel Level Sensor Circuit±Low
Voltage 6E±346. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0463 Fuel Level Sensor Circuit±High
Voltage 6E±349. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0462 Fuel Level Sensor Noisy Signal 6E±351
DTC P0502 VSS Circuit Low Input 6E±353. . . . . . . . .
DTC P0506 Idle Air Control System Low
RPM 6E±356. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0507 Idle Air Control System High
RPM 6E±359. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0562 System Voltage Low 6E±362. . . . . . . . . .
DTC P0563 System Voltage High 6E±364. . . . . . . . .
DTC P0565 Cruise Main Switch Circuit Error 6E±366
DTC P0566 Cruise Cancel Switch Circuit
Error 6E±368. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0567 Cruise Resume Switch Circuit
Error 6E±370. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0568 Cruise Set Switch Circuit Error 6E±372.
DTC P0571 No Brake Switch Signal 6E±374. . . . . . .
DTC P0601 PCM Memory 6E±376. . . . . . . . . . . . . . . .
DTC P0602 PCM Programming Error 6E±378. . . . . .
DTC P0604 PCM RAM Error 6E±380. . . . . . . . . . . . . .
DTC P0606 PCM Internal Performance 6E±382. . . .
DTC P1106 MAP Sensor Circuit Intermittent
High Voltage 6E±384. . . . . . . . . . . . . . . . . . . . . . . . . . .

6E±16
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
PCM Pinout Table, 80-Way Blue Connector ± Row ªF41 ~ 60º
060RY00046
PINPIN FunctionWire ColorIGN ONENG RUNRefer To
F41Throttle Position(TP) 1
Sensor GroundGRN0.0V0.0VGeneral Description and
Operation, TPS
F42Fuel Pump RelayPNK/WHT0.0VB+On Vehicle Service, Fuel
Pump Relay
F43Adaptor CaseVIO/RED0.0V0.0V4L30E T/Mission
F44Bank 1 HO2S 2 Heater
GroundORN/WHT0.0V0.0VGeneral Description and
Operation, Catalyst Monitor
HO2S 2
F45A/C RequestGRN/BLK0.0V0.0VChassis Electrical
F46Stop Lamp SwitchBRN/RED0.0V0.0VChassis Electrical
F47Adaptor CaseVIO/WHTB+B+4L30E T/Mission
F48Throttle Valve DC Motor(±:
REV)BLUDuty CycleDuty CycleGeneral Description and
Operation, ETC
F49Not UsedÐÐÐÐ
F50Bank 2 HO2S 2 GroundORN0.0V0.0VÐ
F51Not UsedÐÐÐÐ
F52Bank 1 HO2S 2 GroundRED0.0V0.0VÐ
F53ECT GroundYEL/BLK0.0V0.0VGeneral Description and
Operation, ECT Sensor
F54Vapor Pressure (Fuel Tank
Pressure) Sensor GroundGRN0.0V0.0VGeneral Description and
Operation, VP Sensor
F55Not UsedÐÐÐÐ
F56Injector Cylinder #5GRN/BLKB+B+General Description and
Operation, Fuel Injector
F57Ignition FeedRED/WHTB+B+Chassis Electrical
F58Class 2 DataORN/BLK0.0V0.0VGeneral Description
F59Not UsedÐÐÐÐ
F60Not UsedÐÐÐÐ

6E±17
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
PCM Pinout Table, 80-Way Blue Connector ± Row ªF61 ~ 80º
060RY00047
PINPIN FunctionWire ColorIGN ONENG RUNRefer To
F61Throttle Position(TP) 2
Sensor GroundGRN/WHT0.0V0.0VGeneral Description and
Operation, TPS
F62Injector Cylinder #2GRN/ORNB+B+General Description and
Operation, Fuel Injector
F63AP Sensor 1 Sensor
GroundRED0.0V0.0VOn-Vehicle Service
F64Injector Cylinder #4GRN/REDB+B+General Description and
Operation, Fuel Injector
F65Throttle Position(TP) 2
Sensor SignalBLU/WHT0.5±0.8V0.8±0.8V (at
idle)General Description and
Operation, TPS
F66Injector Cylinder #3GRNB+B+General Description and
Operation, Fuel Injector
F67ION Sensing ModuleYEL1.555V1.555VGeneral Description and
Operation, ION Sensing
Module
F68ION Sensing ModuleRED1.555V1.555VGeneral Description and
Operation, ION Sensing
Module
F69Injector Cylinder #1GRN/WHTB+B+General Description and
Operation, Fuel Injector
F70ANTI TheftWHT/GRNÐÐÐ
F71Bank 2 HO2S 2 Heater
GroundGRN/WHT0.0V0.0VGeneral Description and
Operation, Catalyst Monitor
HO2S 1
F72Auto Cruise Switch
ResumeWHT/BLU0.0V0.0VChassis Electrical
F73Crankshaft Position
SensorWHT/BLU0.3V2.2VGeneral Description and
Operation, CKP sensor
F74ECT SensorBLU/RED0.5±4.9V0.5±4.9VGeneral Description and
Operation, ECT Sensor
F75Ignition FeedRED/GRNB+B+Chassis Electrical
F76Mode SwitchPNK/BLKB+B+4L30E T/Mission
F77Mode SwitchPNK/BLUB+B+4L30E T/Mission

6E±19
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
PCM Pinout Table, 80-Way Red Connector ± Row ªS1 ~ 20º
060RY00069
PINPIN FunctionWire ColorIGN ONENG RUNRefer To
S1PCM GroundBLK/PNK0.0V0.0VChassis Electrical
S2Bank 1 HO2S 1 Heater
GroundBLK/ORN0.0V0.0VGeneral Description and
Operation, Catalyst Monitor
HO2S
S3Not UsedÐÐÐÐ
S4Not UsedÐÐÐÐ
S55Volt Referenceª2º (CKP
Sensor)WHT5.0V5.0VAppropriate Sensor (CKP
Sensor, AP2 Sensor)
S6Auto Cruise Switch CancelGRY/GRN0.0V0.0VChassis Electrical
S7Purge Duty Solenoid ValveRED/BLUB+B+EVAP Emission Control
System
S8M.I.D0.5 GRNÐÐÐ
S9Not UsedÐÐÐÐ
S10Shift High (Band Apply)BRN/YELB+B+4L30E T/Mission
S11Malfunction Indicator
(Check Engine) LampWHT/GRN0.0VB+Chassis Electrical
S12Not UsedÐÐÐÐ
S13ION Sensing ModuleRED/WHT1.555V1.555VGeneral Description and
Operation, ION Sensing
Module
S14Bank 2 HO2S 1 GroundBLU0.0V0.0VÐ
S15Bank 2 HO2S 2 GroundORN0.0V0.0VÐ
S16Bank 2 HO2S 2 LowBLU0.0V0.1VGeneral Description and
Operation, Catalyst Monitor
HO2S
S17Bank 1 HO2S 1 GroundWHT0.0V0.0VÐ
S18Bank 1 HO2S 1 LowWHT/BLU0.0V0.1VGeneral Description and
Operation, Catalyst Monitor
HO2S

6E±23
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
PCM Pinout Table, 80-Way Red Connector ± Row ªS41 ~ 60º
060RY00050
PINPIN FunctionWire ColorIGN ONENG RUNRefer To
S41AP Sensor 3 Sensor
GroundORN/BLU0.0V0.0VOn-Vehicle Service
S42Bank 2 HO2S 1 Heater
GroundWHT/RED0.0V0.0VGeneral Description and
Operation, Catalyst Monitor
HO2S
S43Solenoid Power SupplyGRY/WHTB+B+4L30E T/Mission
S44Rr Def. RelayRED/WHTÐÐÐ
S45Starter RelayBLK/BLUÐÐÐ
S46Fuel GaugeYEL/REDB+B+Chassis Electrical
S47Water Temp. GaugeWHT/BLKB+B+4L30E T/Mission
S48Fuel GaugeYEL/REDB+B+General Description and
Chassis Electrical
S49DLCRED/WHTB+B+General Description
S50Fuel Sender UnitORN/GRN0.0V0.0VÐ
S51TCC SolenoidBRN/BLU0.0V0.0VT/Mission
S52Vapor Pressure (Fuel Tank
Pressure) Sensor SignalGRY0.2±4.8V0.2±4.8VGeneral Description and
Operation, VP Sensor
S53Power SwitchVIO/REDB+B+4L30E T/Mission
S54Bank 2 HO2S 1 LowBLU0.0V0.1VGeneral Description and
Operation, Catalyst Monitor
HO2S
S55Transmission Output
Speed SensorBLU/GRN0.0V0.0V4L30E T/Mission
S56Not UsedÐÐÐÐ
S57Not UsedÐÐÐÐ
S58Bank 1 HO2S 1 HighORN/BLU0.3V0.1±0.9VGeneral Description and
Operation, Catalyst Monitor
HO2S

6E±36
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Intrusive Diagnostic Tests
This is any on-board test run by the Diagnostic
Management System which may have an effect on
vehicle performance or emission levels.
Warm-Up Cycle
A warm-up cycle means that engine at temperature must
reach a minimum of 70
C (160
F)
and rise at least 22
C
(40
F) over the course of a trip.
Freeze Frame
Freeze Frame is an element of the Diagnostic
Management System which stores various vehicle
information at the moment an emissions-related fault is
stored in memory and when the MIL is commanded on.
These data can help to identify the cause of a fault. Refer
to
Storing And Erasing Freeze Frame Data in this section
for more detailed information.
Failure Records
Failure Records data is an enhancement of the OBD II
Freeze Frame feature. Failure Records store the same
vehicle information as does Freeze Frame, but it will store
that information for any fault which is stored in on-board
memory, while Freeze Frame stores information only for
emission-related faults that command the MIL on.
System Status and Drive Cycle for
Satisfying Federal Inspection/Maintenance
(I/M 240) Regulations
I/M Ready Status means a signal or flag for each
emission system test that had been set in the PCM. I/M
Ready Status indicates that the vehicle on-board
emissions diagnostics have been run. I/M Ready Status
is not concerned whether the emission system passed or
failed the test, only that on-board diagnosis is complete.
Not all vehicles use all possible I/M flags.
Common OBD II Terms
Diagnostic
When used as a noun, the word diagnostic refers to any
on-board test run by the vehicle's Diagnostic
Management System. A diagnostic is simply a test run on
a system or component to determine if the system or
component is operating according to specification. There
are many diagnostics, shown in the following list:

Misfire

Oxygen sensors

Oxygen sensor heaters

EGR

Catalyst monitoring
Enable Criteria
The term ªenable criteriaº is engineering language for the
conditions necessary for a given diagnostic test to run.
Each diagnostic has a specific list of conditions which
must be met before the diagnostic will run. ªEnable
criteriaº is another way of saying ªconditions requiredº.The enable criteria for each diagnostic is listed on the first
page of the DTC description in Section 6E under the
heading ªConditions for Setting the DTCº. Enable criteria
varies with each diagnostic, and typically includes, but is
not limited to the following items:

engine speed

vehicle speed

ECT

MAF/MAP

barometric pressure

IAT

TP

high canister purge

fuel trim

TCC enabled

A/C on
Trip
Technically, a trip is a key on-run-key off cycle in which all
the enable criteria for a given diagnostic are met, allowing
the diagnostic to run. Unfortunately, this concept is not
quite that simple. A trip is official when all the enable
criteria for a given diagnostic are met. But because the
enable criteria vary from one diagnostic to another, the
definition of trip varies as well. Some diagnostics are run
when the vehicle is at operating temperature, some when
the vehicle first starts up; some require that the vehicle be
cruising at a steady highway speed, some run only when
the vehicle is idle; some diagnostics function with the
TCC disabled. Some run only immediately following a
cold engine start-up.
A trip then, is defined as a key on-run-key off cycle in
which the vehicle was operated in such a way as to satisfy
the enabling criteria for a given diagnostic, and this
diagnostic will consider this cycle to be one trip. However,
another diagnostic with a different set of enable criteria
(which were not met) during this driving event, would not
consider it a trip. No trip will occur for that particular
diagnostic until the vehicle is driven in such a way as to
meet all the enable criteria.
The Diagnostic Executive
The Diagnostic Executive is a unique segment of
software which is designed to coordinate and prioritize
the diagnostic procedures as well as define the protocol
for recording and displaying their results. The main
responsibilities of the Diagnostic Executive are listed as
the following:

Commanding the MIL (ªCheck Engineº lamp) on and
off

DTC logging and clearing

Freeze Frame data for the first emission related DTC
recorded

Non-emission related Service Lamp

Operating conditions Failure Records buffer, (the
number of records will vary)

Current status information on each diagnostic

System Status (I/M ready)

6E±57
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Primary System-Based Diagnostic
Primary System-Based Diagnostic
There are primary system-based diagnostics which
evaluate system operation and its effect on vehicle
emissions. The primary system-based diagnostics are
listed below with a brief description of the diagnostic
function:
Oxygen Sensor Diagnosis
The fuel control heated oxygen sensors (Bank 1 HO2S 1
and Bank 2 HO2S 1) are diagnosed for the following
conditions:

Heater performance (time to activity on cold start)

Slow response

Response time (time to switch R/L or L/R)

Inactive signal (output steady at bias voltage ±
approx. 450 mV)

Signal fixed high

Signal fixed low
The catalyst monitor heated oxygen sensors (Bank 1
HO2S 2 and Bank 2 HO2S 2) are diagnosed for the
following conditions:

Heater performance (time to activity on cold start).

Signal fixed low during steady state conditions or
power enrichment (hard acceleration when a rich
mixture should be indicated).

Signal fixed high during steady state conditions or
deceleration mode (deceleration when a lean mixture
should be indicated).

Inactive sensor (output steady at approx. 438 mV).
If the oxygen sensor pigtail wiring, connector or terminal
are damaged, the entire oxygen sensor assembly must
be replaced. DO NOT attempt to repair the wiring,
connector or terminals. In order for the sensor to function
properly, it must have clean reference air provided to it.
This clean air reference is obtained by way of the oxygen
sensor wire(s). Any attempt to repair the wires, connector
or terminals could result in the obstruction of the
reference air and degrade oxygen sensor performance.
Refer to
On-Vehicle Service, Heated Oxygen Sensors in
this section.
Fuel Control Heated Oxygen Sensor
The main function of the fuel control heated oxygen
sensors is to provide the control module with exhaust
stream oxygen content information to allow proper fueling
and maintain emissions within mandated levels. After it
reaches operating temperature, the sensor will generate
a voltage, inversely proportional to the amount of oxygen
present in the exhaust gases. The control module uses
the signal voltage from the fuel control heated oxygen
sensors while in closed loop to adjust fuel injector pulse
width. While in closed loop, the PCM can adjust fuel
delivery to maintain an air/fuel ratio which allows the best
combination of emission control and driveability. The fuel
control heated oxygen sensors are also used to
determine catalyst efficiency.
HO2S Heater
Heated oxygen sensors are used to minimize the amount
of time required for closed loop fuel control to begin
operation and to allow accurate catalyst monitoring. The
oxygen sensor heater greatly decreases the amount of
time required for fuel control sensors (Bank 1 HO2S 1 and
Bank2 HO2S 1) to become active. Oxygen sensor
heaters are required by catalyst monitor and sensor
(Bank 1 HO2S 2 and Bank 2 HO2S 2) to maintain a
sufficiently high temperature which allows accurate
exhaust oxygen content readings further away from the
engine.
Catalyst Monitor Heated Oxygen Sensors
and Diagnostic Operation
TS24067
To control emissions of hydrocarbons (HC), carbon
monoxide (CO), and oxides of nitrogen (NOx), a
three-way catalytic converter is used. The catalyst within
the converter promotes a chemical reaction which
oxidizes the HC and CO present in the exhaust gas,
converting them into harmless water vapor and carbon
dioxide. The catalyst also reduces NOx, converting it to
nitrogen. The PCM has the ability to monitor this process
using the pre-catalyst and post-catalyst heated oxygen
sensors. The pre-catalyst sensor produces an output
signal which indicates the amount of oxygen present in
the exhaust gas entering the three-way catalytic
converter. The post-catalyst sensor produces an output
signal which indicates the oxygen storage capacity of the
catalyst; this in turn indicates the catalyst's ability to
convert exhaust gases efficiently. If the catalyst is
operating efficiently, the pre-catalyst signal will be far
more active than that produced by the post-catalyst
sensor.
In addition to catalyst monitoring, the heated oxygen
sensors have a limited role in controlling fuel delivery. If
the sensor signal indicates a high or low oxygen content
for an extended period of time while in closed loop, the
PCM will adjust the fuel delivery slightly to compensate.