2002 ISUZU AXIOM wiring diagram

6E±531
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Hesitation, Sag, Stumble Symptom

 
StepNo Ye s Value(s) Action
101. Check items that can cause the engine to run lean.
Refer to
Diagnostic Aids in DTC P0171 Diagnostic
Support
.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 11
111. Check for proper ignition voltage output with spark
tester J 26792 (ST-125). Refer to
Electronic Ignition
System
for the procedure.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 12
121. Check for a loose ignition coil ground and ION
Sensing module circuit.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 13
131. Check the ignition coils for cracks or carbon
tracking.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 14
141. Remove spark plugs and check for wet plugs,
cracks, wear, improper gap, burned electrodes, or
heavy deposits. Refer to
Electronic Ignition
System
.
NOTE: If spark plugs are gas or oil fouled, the cause of
the fouling must be determined before replacing the
spark plugs.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 15
151. Check the PCM grounds for clearness, tightness
and proper routing. Refer to the PCM wiring
diagrams in Electrical Diagnosis.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 16
161. Check the MAF sensor connections.
2. If a problem is found, replace the faulty terminals as
necessary. Refer to
Electrical Diagnosis for wiring
repair procedures.
Was a problem found?
ÐVerify repairGo to Step 17

6E±572
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
General Description (PCM and
Sensors)
58X Reference PCM Input
The powertrain control module (PCM) uses this signal
from the crankshaft position (CKP) sensor to calculate
engine RPM and crankshaft position at all engine speeds.
The PCM also uses the pulses on this circuit to initiate
injector pulses. If the PCM receives no pulses on this
circuit, DTC P0337 will set. The engine will not start and
run without using the 58X reference signal.
A/C Request Signal
This signal tells the PCM when the A/C mode is selected
at the A/C control head. The PCM uses this to adjust the
idle speed before turning ªONº the A/C clutch. The A/C
compressor will be inoperative if this signal is not
available to the PCM.
Refer to
A/C Clutch Circuit Diagnosis section for A/C
wiring diagrams and diagnosis for the A/C electrical
system.
Crankshaft Position (CKP) Sensor
The crankshaft position (CKP) sensor provides a signal
used by the powertrain control module (PCM) to calculate
the ignition sequence. The CKP sensor initiates the 58X
reference pulses which the PCM uses to calculate RPM
and crankshaft position.
Refer to
Electronic Ignition System section for additional
information.
0013
Engine Coolant Temperature (ECT) Sensor
The engine coolant temperature (ECT) sensor is a
thermistor (a resistor which changes value based on
temperature) mounted in the engine coolant stream. Low
coolant temperature produces a high resistance of
100,000 ohms at ±40
C (±40
F). High temperature
causes a low resistance of 70 ohms at 130
C (266
F).
The PCM supplies a 5-volt signal to the ECT sensor
through resistors in the PCM and measures the voltage.
The signal voltage will be high when the engine is cold and
low when the engine is hot. By measuring the voltage, thePCM calculates the engine coolant temperature. Engine
coolant temperature affects most of the systems that the
PCM controls.
The Tech 2 displays engine coolant temperature in
degrees. After engine start-up, the temperature should
rise steadily to about 85
C (185
F). It then stabilizes
when the thermostat opens. If the engine has not been
run for several hours (overnight), the engine coolant
temperature and intake air temperature displays should
be close to each other. A hard fault in the engine coolant
sensor circuit will set DTC P0177 or DTC P0118. An
intermittent fault will set a DTC P1114 or P1115.
0016
Electrically Erasable Programmable Read
Only Memory (EEPROM)
The electrically erasable programmable read only
memory (EEPROM) is a permanent memory chip that is
physically soldered within the PCM. The EEPROM
contains the program and the calibration information that
the PCM needs to control powertrain operation.
Unlike the PROM used in past applications, the EEPROM
is not replaceable. If the PCM is replaced, the new PCM
will need to be programmed. Equipment containing the
correct program and calibration for the vehicle is required
to program the PCM.
Fuel Control Heated Oxygen Sensors
The fuel control heated oxygen sensors (Bank 1 HO2S 1
and Bank 2 HO2S 1) are mounted in the exhaust stream
where they can monitor the oxygen content of the exhaust
gas. The oxygen present in the exhaust gas reacts with
the sensor to produce a voltage output. This voltage
should constantly fluctuate from approximately 100 mV to
900 mV. The heated oxygen sensor voltage can be
monitored with a Tech 2. By monitoring the voltage output
of the oxygen sensor, the PCM calculates the pulse width
command for the injectors to produce the proper
combustion chamber mixture.

Low HO2S voltage is a lean mixture which will result in
a rich command to compensate.

High HO2S voltage is a rich mixture which will result in
a lean command to compensate.

6E±583
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
between the seats. In extreme cases, exhaust blow-by
and damage beyond simple gap wear may occur.
Cracked or broken insulators may be the result of
improper installation, damage during spark plug
re-gapping, or heat shock to the insulator material. Upper
insulators can be broken when a poorly fitting tool is used
during installation or removal, when the spark plug is hit
from the outside, or is dropped on a hard surface. Cracks
in the upper insulator may be inside the shell and not
visible. Also, the breakage may not cause problems until
oil or moisture penetrates the crack later.
TS23994
A/C Clutch Diagnosis
A/C Clutch Circuit Operation
A 12-volt signal is supplied to the A/C request input of the
PCM when the A/C is selected through the A/C control
switch.
The A/C compressor clutch relay is controlled through the
PCM. This allows the PCM to modify the idle air control
position prior to the A/C clutch engagement for better idle
quality. If the engine operating conditions are within their
specified calibrated acceptable ranges, the PCM will
enable the A/C compressor relay. This is done by
providing a ground path for the A/C relay coil within the
PCM. When the A/C compressor relay is enabled,
battery voltage is supplied to the compressor clutch coil.
The PCM will enable the A/C compressor clutch
whenever the engine is running and the A/C has been
requested. The PCM will not enable the A/C compressor
clutch if any of the following conditions are met:

The throttle is greater than 90%.

The engine speed is greater than 6315 RPM.

The ECT is greater than 119
C (246
F).

The IAT is less than 5
C (41
F).

The throttle is more than 80% open.
A/C Clutch Circuit Purpose
The A/C compressor operation is controlled by the
powertrain control module (PCM) for the following
reasons:

It improvises idle quality during compressor clutch
engagement.

It improvises wide open throttle (WOT) performance.

It provides A/C compressor protection from operation
with incorrect refrigerant pressures.
The A/C electrical system consists of the following
components:

The A/C control head.

The A/C refrigerant pressure switches.

The A/C compressor clutch.

The A/C compressor clutch relay.

The PCM.
A/C Request Signal
This signal tells the PCM when the A/C mode is selected
at the A/C control head. The PCM uses this to adjust the
idle speed before turning on the A/C clutch. The A/C
compressor will be inoperative if this signal is not
available to the PCM.
Refer to
A/C Clutch Circuit Diagnosis section for A/C
wiring diagrams and diagnosis for A/C electrical system.
General Description (Evaporative
(EVAP) Emission System)
EVAP Emission Control System Purpose
The basic evaporative emission (EVAP) control system
used on all vehicles is the charcoal canister storage
method. Gasoline vapors from the fuel tank flow into the
canister through the inlet labeled ªTANK.º These vapors
are absorbed into the activated carbon (charcoal) storage
device (canister) in order to hold the vapors when the
vehicle is not operating. The canister is purged by PCM
control when the engine coolant temperature is over 60
C
(140
F), the IAT reading is over 10
C (50
F), and the
engine has been running. Air is drawn into the canister
through the air inlet grid. The air mixes with the vapor and
the mixture is drawn into the intake manifold.
EVAP Emission Control System Operation
The EVAP canister purge is controlled by a solenoid valve
that allows the manifold vacuum to purge the canister.
The powertrain control module (PCM) supplies a ground
to energize the solenoid valve (purge on). The EVAP
purge solenoid control is pulse-width modulated (PWM)
(turned on and off several times a second). The duty
cycle (pulse width) is determined by engine operating
conditions including load, throttle positron, coolant
temperature and ambient temperature. The duty cycle is
calculated by the PCM. The output is commanded when
the appropriate conditions have been met. These
conditions are:

The engine is fully warmed up.

The engine has been running for a specified time.

The IAT reading is above 10
C (50
F).

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±11
Diagnosis
Electronic Diagnosis
How To Diagnose The Problem
1. To avoid incorrect diagnostics, this book needs to be
followed accurately. Unless stated, do not jump
directly to a section that could contain the solution.
Some important information may be missed.
2. The sections in CAPITALS and bold are the main
sections that can be found in the contents.
3. The GO TO ªSECTIONº means to continue to check
going to the ªsectionº.
4. The GO THROUGH ªSECTIONº means to go
through the ªsectionº and then to go back to the place
the GO THROUGH was written.
5. BASIC ELECTRIC CIRCUITS:
You should understand the basic theory of electricity.
This includes the meaning of voltage, amps, ohms,
and what happens in a circuit with an open or shorted
wire. You should also be able to read and understand
wiring diagrams.
Check Trans Indicator
Find CHECK TRANS indicator and verify if it is
A. Flashing: GO TO DIAGNOSTIC CHECK.
B. Staying on: GO THROUGH CHECK TRANS
CHECK.
C. Is never ON when the ignition key is turned on: GO
THROUGH CHECK TRANS CHECK
D. Is ON during 2 seconds at ignition but OFF after:
Normal operation. No DTC or malfunction.
821R200014
Diagnostic Check
This test determines if the transmission or its input or
output connections or sensors are failing.
1. Connect the Tech 2: GO THROUGH Tech 2 OBD II
CONNECTION.2. Turn on the ignition but not the engine.
3. Push ªF0º on Tech 2 to see the Diagnostic Trouble
Code (DTC):
4. Do you have a DTC?
YES: write down all code numbers and do the DTC
CHECK
NO: the DTC can not help you finding the problem.
1. GO THROUGH ªCHECK TRANSº CHECK
2. If it is flashing and the flash is 0.2 seconds ON and
0.2 seconds OFF, this means that you should
have a DTC stored. Please recheck GO TO
DIAGNOSTIC CHECK and if you find the same
problem, replace the Powertrain Control Module
(PCM).
Normal
C07R200005
Abnormal
C07R200006

8D±1
WIRING SYSTEM
AXIOM
BODY AND ACCESSORIES
WIRING SYSTEM
CONTENTS
Fuse, Relay and Diode 8D±2. . . . . . . . . . . . . . . . . . .
Relay / Fuse Box Location 8D±2. . . . . . . . . . . . . .
Relay / Fuse Box (Instrument Panel) 8D±3. . . . .
Relay / Fuse Box (Engine Room) 8D±4. . . . . . . .
Circuit Diagram 8D±5. . . . . . . . . . . . . . . . . . . . . . . . .
Fuse Block Circuit 8D±5. . . . . . . . . . . . . . . . . . . . .
Ground Location (Engine Room) 8D±6. . . . . . . .
Ground Location (Cabin) 8D±7. . . . . . . . . . . . . . .
Starter and Generator 8D±8. . . . . . . . . . . . . . . . . .
PCM±1 8D±9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PCM±2 8D±10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Headlight and Fog Light 8D±11. . . . . . . . . . . . . . . .
Turn, Hazard, Stop, Back Up, Horn and
A/T Shift Lock 8D±12. . . . . . . . . . . . . . . . . . . . . . . .
Dome Light, Luggage Room Light, Courtesy
Light, Spot Light, and Warning Buzzer 8D±13. . .
Power Window and Door Lock 8D±14. . . . . . . . . .
Alarm and Relay Control Unit 8D±15. . . . . . . . . . . Rear Wiper/Washer and Rear Defogger 8D±16. .
Audio, Clock, Cigarette Lighter and
ACC Socket 8D±17. . . . . . . . . . . . . . . . . . . . . . . . . .
MID 8D±18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Door Mirror 8D±19. . . . . . . . . . . . . . . . . . . . . . . . . . .
Meter 8D±20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Anti-theft with Keyless Entry 8D±21. . . . . . . . . . . .
Air Conditioning 8D±22. . . . . . . . . . . . . . . . . . . . . . .
ABS 8D±23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SRS±Air Bag 8D±24. . . . . . . . . . . . . . . . . . . . . . . . . .
Intelligent Suspension 8D±25. . . . . . . . . . . . . . . . . .
T.O.D 8D±26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sunroof 8D±27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Illumination Light 8D±28. . . . . . . . . . . . . . . . . . . . . .
Windshield Wiper and Washer 8D±29. . . . . . . . . .
Power Seat 8D±30. . . . . . . . . . . . . . . . . . . . . . . . . . .
Seat Heater 8D±31. . . . . . . . . . . . . . . . . . . . . . . . . . .

8D±5
WIRING SYSTEM
Circuit Diagram
Fuse Block Circuit
D08R200017

RESTRAINT CONTROL SYSTEM 9J1±2
Diagnostic Information
Diagnostic Procedures
WARNING: W H E N FA S T E N E R S A R E R E M O V E D ,
ALWAYS REINSTALL THEN AT THE SAME
LOCATION FROM WHICH THEY WERE REMOVED. IF
A FASTENER NEEDS TO BE REPLACED, USE THE
CORRECT PART NUMBER FASTENER FOR THAT
APPLICATION. IF THE CORRECT PART NUMBER
FASTENER IS NOT AVAILABLE, A FASTENER OF
EQUAL SIZE AND STRENGTH (OR STRONGER) MAY
BE USED. FASTENERS THAT ARE NOT REUSED,
AND THOSE REQUIRING THREAD LOCKING
COMPOUND WILL BE CALLED OUT. THE CORRECT
TORQUE VALUE MUST BE USED WHEN
INSTALLING FASTENERS THAT REQUIRE IT. IF THE
ABOVE CONDITIONS ARE NOT FOLLOWED, PARTS
OR SYSTEM DAMAGE COULD RESULT.
WARNING: T O AV O I D D E P L O Y M E N T W H E N
TROUBLESHOOTING THE SRS, DO NOT USE
ELECTRICAL TEST EQUIPMENT SUCH AS A
BATTERY±POWERED OR AC±POWERED
VOLTMETER, OHMMETER, ETC., OR ANY TYPE OF
ELECTRICAL EQUIPMENT OTHER THAN THAT
SPECIFIED IN THIS MANUAL. DO NOT USE A
NONPOWERED, PROBE±TYPE TESTER.
INSTRUCTIONS IN THIS MANUAL MUST BE
FOLLOWED CAREFULLY, OTHERWISE PERSONAL
INJURY MAY RESULT.
The diagnostic procedures used in this section are
designed to aid in finding and repairing SRS problems.
Outlined below are the steps to find and repair SRS
problems quickly and effectively. Failure to carefully
follow these procedures may result in extended
diagnostic time, incorrect diagnosis and incorrect parts
Replacement.
1.Perform The ªSRS Diagnostic System Check.º
The ªSRS Diagnostic System Checkº should always be
the starting point of any SRS diagnostics. The ªSRS
Diagnostic System Checkº checks for proper ªAIR BAGº
warning lamp operation and checks for SRS trouble
codes using both ªFlash Codeº and ªScan Toolº Methods.
2.Refer To The Proper Diagnostic Chart As Directed
By The ªSRS Diagnostic System Check.º
The ªSRS Diagnostic System Checkº will lead you to the
correct chart to diagnose any SRS problems. Bypassing
these procedures may result in extended diagnostic time,
incorrect diagnosis and incorrect parts Replacement.
3.Repeat the ªSRS Diagnostic System Checkº After
Any Repair Or Diagnostic Procedures Have Been
Performed.
Performing the ªSRS Diagnostic System Checkº after all
repair or diagnostic procedures will assure that the repair
has been made correctly and that no other conditions
exist.
Diagnostic Codes
The Sensing and Diagnostic Module (SDM) maintains a
history record of all diagnostic codes that have been
detected since the SRS codes were last cleared during
service.
1. Active CodesÐFaults that are presently detected this
ignition cycle. Active codes are stored in RAM
(Random Access Memory).
2. History CodesÐAll faults detected since the last time
the history fault memory was cleared. History codes
are stored in EEPROM. (Electronically Erasable
Programmable Read only Memory)
How To Read Trouble Codes
All codes (Active and history) can be read (or cleared) by
using a scan tool or equivalent.
If a DTC is not available, have the vehicle serviced by
dealer.
How To Clear Trouble Codes
Trouble codes can only be cleared by using a scan tool. If
a scan tool is not available then inform the owner of the
stored codes and suggest that the codes are cleared
upon the next visit to a dealership.
Scan Tool Diagnostics
A scan tool can be used to read current and history codes
and to clear all history codes after a repair is complete.
The scan tool must be updated to communicate with the
SRS through a replaceable cartridge for SRS
diagnostics. To use the scan tool, connect it to the DLC
and turn the ignition switch ªONº. Then follow the
manufacturer's directions for communication with the
SRS. The scan tool reads serial data from the SDM
ªSerial Dataº output (terminal 24) to the DLC.
Basic Knowledge Required
Before using this section of the Service Manual, there is
some basic knowledge which will be required. Without
this knowledge, you will have trouble using the diagnostic
procedures in this section. Use care to prevent harm or
unwanted deployment. Read all cautions in the service
manual and on warning labels attached to SRS
components.
Basic Electrical Circuits
You should understand the basic theory of electricity
including series and parallel circuits, and understand the
voltage drops across series resistors. You should know
the meaning of voltage (volts), current (amps), and
resistance (ohms). You should understand what happens
in a circuit with an open or a shorted wire. You should be
able to read and understand a wiring diagram.