wiring diagram ISUZU AXIOM 2002 Service User Guide

6E±33
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnosis
Strategy-Based Diagnostics
Strategy-Based Diagnostics
The strategy-based diagnostic is a uniform approach to
repair all Electrical/Electronic (E/E) systems. The
diagnostic flow can always be used to resolve an E/E
system problem and is a starting point when repairs are
necessary. The following steps will instruct the technician
how to proceed with a diagnosis:
1. Verify the customer complaint.

To verify the customer complaint, the technician
should know the normal operation of the system.
2. Perform preliminary checks.

Conduct a thorough visual inspection.

Review the service history.

Detect unusual sounds or odors.

Gather diagnostic trouble code information to
achieve an effective repair.
3. Check bulletins and other service information.

This includes videos, newsletters, etc.
4. Refer to service information (manual) system
check(s).

ªSystem checksº contain information on a system
that may not be supported by one or more DTCs.
System checks verify proper operation of the
system. This will lead the technician in an
organized approach to diagnostics.
5. Refer to service diagnostics.
DTC Stored
Follow the designated DTC chart exactly to make an
effective repair.
No DTC
Select the symptom from the symptom tables. Follow the
diagnostic paths or suggestions to complete the repair.
You may refer to the applicable component/system check
in the system checks.
No Matching Symptom
1. Analyze the complaint.
2. Develop a plan for diagnostics.
3. Utilize the wiring diagrams and the theory of
operation.
Combine technician knowledge with efficient use of the
available service information.
Intermittents
Conditions that are not always present are called
intermittents. To resolve intermittents, perform the
following steps:
1. Observe history DTCs, DTC modes, and freeze
frame data.
2. Evaluate the symptoms and the conditions described
by the customer.3. Use a check sheet or other method to identify the
circuit or electrical system component.
4. Follow the suggestions for intermittent diagnosis
found in the service documentation.
Most Scan Tools, such as the Tech 2, have data-capturing
capabilities that can assist in detecting intermittents.
No Trouble Found
This condition exists when the vehicle is found to operate
normally. The condition described by the customer may
be normal. Verify the customer complaint against another
vehicle that is operating normally. The condition may be
intermittent. Verify the complaint under the conditions
described by the customer before releasing the vehicle.
1. Re-examine the complaint.
When the complaint cannot be successfully found or
isolated, a re-evaluation is necessary. The complaint
should be re-verified and could be intermittent as
defined in
Intermittents section, or could be normal.
2. Repair and verify.
After isolating the cause, the repairs should be made.
Validate for proper operation and verify that the
symptom has been corrected. This may involve road
testing or other methods to verify that the complaint
has been resolved under the following conditions:

Conditions noted by the customer.

If a DTC was diagnosed, verify a repair by
duplicating conditions present when the DTC was
set as noted in the Failure Records or Freeze
Frame data.
Verifying Vehicle Repair
Verification of the vehicle repair will be more
comprehensive for vehicles with OBD II system
diagnostics. Following a repair, the technician should
perform the following steps:
IMPORTANT:Follow the steps below when you verify
repairs on OBD II systems. Failure to follow these steps
could result in unnecessary repairs.
1. Review and record the Failure Records and the
Freeze Frame data for the DTC which has been
diagnosed (Freeze Frame data will only be stored for
an A or B type diagnostic and only if the MIL(ºCheck
Engineº lamp) has been requested).
2. Clear the DTC(S).
3. Operate the vehicle within conditions noted in the
Failure Records and Freeze Frame data.
4. Monitor the DTC status information for the DTC which
has been diagnosed until the diagnostic test
associated with that DTC runs.
General Service Information
OBD II Serviceablity Issues
With the introduction of OBD II diagnostics across the
entire passenger car and light-duty truck market in 1996,
illumination of the MIL (ªCheck Engineº lamp) due to a
non-vehicle fault could lead to misdiagnosis of the
vehicle, increased warranty expense and customer

6E±506
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Symptom Diagnosis
Preliminary Checks
Before using this section, perform the ªOn-Board
Diagnostic (OBD) System Checkº and verify all of the
following items:

The powertrain control module (PCM), and
malfunction indicator lamp (MIL) (Check Engine
lamp) and Reduced Power Lamp (RPL) are operating
correctly.

There are no DTC(s) stored.

Tech 2 data is within normal operating range. Refer to
Typical Scan Data Values.

Verify the customer complaint and locate the correct
symptom in the table of contents. Perform the
procedure included in the symptom chart.
Visual/Physical Check
Several of the symptom procedures call for a careful
visual/physical check. This can lead to correcting a
problem without further checks and can save valuable
time.
This check should include the following items:

PCM grounds for cleanliness, tightness and proper
location.

Vacuum hoses for splits, kinks, and proper
connections, as shown on the ªVehicle Emission
Control Informationº label. Check thoroughly for any
type of leak or restriction.

Air intake ducts for collapsed or damaged areas.

Air leaks at throttle body mounting area, mass air flow
(MAF) sensor and intake manifold sealing surfaces.

Ignition components for cracking, hardness, and
carbon tracking.

Wiring for proper connections, pinches and cuts.
Intermittents
IMPORTANT:An intermittent problem may or may not
turn on the malfunction indicator lamp (MIL) or store a
DTC. DO NOT use the Diagnostic Trouble Code (DTC)
charts for intermittent problems. The fault must be
present to locate the problem.
Most intermittent problems are caused by faulty electrical
connections or wiring. Perform a careful visual/physical
check for the following conditions:

Poor mating of the connector halves or a terminal not
fully seated in the connector (backed out).

Improperly formed or damaged terminal.

All connector terminals in the problem circuit should
be carefully checked for proper contact tension.

Poor terminal-to-wire connection. This requires
removing the terminal from the connector body to
check.
Road test the vehicle with a J 39200 Digital Multimeter
connected to a suspected circuit. An abnormal voltage
when the malfunction occurs is a good indication that
there is a fault in the circuit being monitored.
Use a Tech 2 to help detect intermittent conditions. The
scan tool has several features that can be used to locatean intermittent condition. Use the following feature to find
intermittent faults:

Using a Tech 2's ªFreeze Frameº buffer or ªFailure
Recordsº buffer can aid in locating an intermittent
condition. Review and record the information in the
freeze frame or failure record associated with the
intermittent DTC being diagnosed. The vehicle can
be driven within the conditions that were present
when the DTC originally set.
To check for loss of diagnostic code memory, disconnect
the MAP sensor and idle the engine until the MIL (Check
Engine lamp) comes on. DTC P0107 should be stored
and kept in memory when the ignition is turned ªOFFº. If
not, the PCM is faulty. When this test is completed, make
sure that you clear the DTC P0107 from memory.
An intermittent MIL (Check Engine lamp) with no stored
DTC may be caused by the following:

Ignition coil shorted to ground and arcing.

MIL (Check Engine lamp) wire to PCM shorted to
ground.

Poor PCM grounds. Refer to the PCM wiring
diagrams.
Check for improper installation of electrical options such
as lights, cellular phones, etc. Check all wires from the
PCM to the ignition coils for poor connections.
Check for an open diode across the A/C compressor
clutch and check for other open diodes (refer to wiring
diagrams in
Electrical Diagnosis).
If problem has not been found, refer to
PCM Connector
Symptom
tables.

Check the ªCalibration IDº of the PCM, and compare it
with the latest Isuzu service bulletins and/or Isuzu
EEPROM reprogramming equipment to determine if
an update to the PCM's reprogrammable memory
has been released. To check the ªCalibration IDº,
connect the Tech 2, then look for ªPowertrainº, then
select ªCalibration IDº. This identifies the contents of
the reprogrammable software and calibration
contained in the PCM. If the ªCalibration IDº is not the
most current available, it is advisable to reprogram
the PCM's EEPROM memory, which may either help
identify a hard-to-find problem or may fix the problem.

Calibration ID (example)
Part number 9377709
Broadcast Code CYYD
Identifier 801

6E±510
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Surges and/or Chuggles 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.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐGo to Step 11Verify repair
111. Check for proper ignition voltage output with spark
tester J 26792 (ST-125). Refer to
Electric Ignition
System
for 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 15
141. Remove the 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 injector connections.
2. If any of the injector connectors are connected to an
incorrect cylinder, correct as necessary.
Was a problem found?
ÐVerify repairGo to Step 16
161. Check PCM grounds for the cleanliness, tightness
and proper locations. 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 17
171. Check 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 18
181. Visually/physically check vacuum hoses for splits,
kinks, and proper connections and routing as
shown on the ªVehicle Emission Control
Informationº label.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 19

6E±513
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Lack of Power, Sluggish, or Spongy Symptoms

 
StepNo Ye s Value(s) Action
101. Remove the 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 11
111. 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 12
121. Check the PCM grounds for cleanliness, tightness
and proper locations. 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 13
131. Check the exhaust system for possible restriction:

Inspect the exhaust system for damaged or
collapsed pipes.

Inspect the muffler for heat distress or possible
internal failure.

Check for a possible plugged three-way
catalytic converter by checking the exhaust
system back pressure. Refer to
Restricted
Exhaust System Check
.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 14
141. Check the torque converter clutch (TCC) for proper
operation. Refer to
4L30-E Transmission
Diagnosis
.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 15
151. Check for an engine mechanical problem. Check
for low compression, incorrect or worn camshaft,
loose timing belt, etc. Refer to
Engine Mechanical.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 16
161. 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?
ÐVerify repair
Contact
Technical
Assistance

6E±517
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Rough, Unstable, or Incorrect Idle, Stalling Symptom

StepActionValue(s)Ye sNo
1DEFINITION:
Engine runs unevenly at idle. If severe, the engine or
vehicle may shake. Engine idle speed may vary in
RPM. Either condition may be severe enough to stall
the engine.
Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Was the ªElectric Throttle Control (ETC) System
Checkº performed?
ÐGo to Step 3
Go to ETC
System
Check
31. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?
ÐGo to Step 14Go to Step 4
4Was a visual/physical check performed?
ÐGo to Step 5
Go to Visual/
Physical
Check
51. Check the PCM grounds for cleanliness, 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 6
6Observe the long term fuel trim on the Tech 2.
Is the long term fuel trim significantly in the negative
range (rich condition)?
ÐGo to Step 7Go to Step 8
71. Check items that can cause the engine to run rich.
Refer to
Diagnostic Aids in DTC P0172 Diagnostic
Support
.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 10
8Is the long term fuel trim significantly in the positive
range (lean condition)?
ÐGo to Step 9Go to Step 10
91. 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 10
101. Check for incorrect idle speed. Ensure that the
following conditions are present:

The engine is fully warm.

The accessories are ªOFFº.
2. Using a Tech 2, monitor the Engine Speed.
Is the Engine Speed within the specified values?
Desired Idle
Speed
Go to Step 12Go to Step 11

6E±527
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Cuts Out, Misses Symptom

StepActionValue(s)Ye sNo
1DEFINITION:
Steady pulsation or jerking that follows engine speed;
usually more pronounced as engine load increases.
Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?
ÐGo to Step 14Go to Step 3
3Was a visual/physical check performed?
ÐGo to Step 4
Go to Visual/
Physical
Check
4Was the ªElectric Throttle Control (ETC) System
Checkº performed?
ÐGo to Step 5
Go to ETC
System
Check
51. 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 6
6Observe the long term fuel trim on the Tech 2.
Is the long term fuel trim significantly in the negative
range (rich condition)?
ÐGo to Step 7Go to Step 8
71. Check items that can cause the engine to run rich.
Refer to
Diagnostic Aids in DTC P0172 Diagnostic
Support
.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 10
8Is the long term fuel trim significantly in the positive
range (lean condition)?
ÐGo to Step 9Go to Step 10
91. 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 10
101. Check for incorrect idle speed. Ensure that the
following conditions are present:

The engine is fully warm.

The accessories are ªoffº.
2. Using a Tech 2, monitor the Engine Speed.
Is the Engine Speed within the specified values?
Desired Idle
Speed
Go to Step 12Go to Step 11

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