ISUZU AXIOM 2002 Service Repair Manual

6E±94
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Reduced Power Lamp (RPL) ªONº Steady

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Ignition ªOFFº, disconnect Multiplex Control Unit.
2. Ignition ªONº, observe the RPL (Reduced Power
Lamp).
Is the RPL ªONº?
ÐGo to Step 3Go to Step 4
31. Ignition ªOFFº, disconnect the instrument panel
cluster.
2. Check the RPL driver circuit between the Multiplex
Control Unit and the instrument panel cluster for a
short to ground.
3. If a problem is found, repair as necessary.
Was the RPL driver circuit shorted to ground?
ÐVerify repairGo to Step 4
41. Replace the Multiplex Control Unit.
2. Install the Tech 2
3. Ignition ªONº.
4. Using the Tech 2 output controls function, select
RPL dash lamp control and command the RPL
ªOFFº. (Refer to the Miscellaneous test)
Did the MIL turn ªOFFº?
ÐVerify repairGo to Step 5
51. Ignition ªOFFº.
2. Disconnect the PCM.
3. Check the circuit (Lamp driver Circuit) between
PCM and Multiplex Control Unit.
Was a problem found?
ÐGo to Step 6Go to Step 7
6Locate and repair the circuit between Multiplex Control
Unit and PCM open circuit.
Is the action complete?
ÐGo to Step 7Ð
71. Install the Tech 2
2. Ignition ªONº.
3. Using the Tech 2 output controls function, select
RPL dash lamp control and command the RPL
ªOFFº. (Refer to the Miscellaneous test)
Did the MIL turn ªOFFº?
Ð
Go to Verify
repair
Go to Step 8
81. Ignition ºOFFº.
2. Disconnect the PCM.
3. Check the circuit (DLC line) between PCM and
DLC.
Was a problem found?
ÐGo to Step 9Go to Step 10

6E±95
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Reduced Power Lamp (RPL) ªONº Steady

 
StepNo Ye s Value(s) Action
9Locate and repair the circuit between PCM and DLC.
Is the action complete?
ÐGo to Step 2Ð
10Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed.
Refer to ON-Vehicle Service in Power Control
Module and Sensors for procedures.
And also refer to latest Service Bulletin.
Check to see if the latest software is released or not.
And then Down Load the LATEST PROGRAMMED
SOFTWARE to the replacement PCM.
Is the action complete?
Ð
Go to OBD
System
Check
Ð

6E±96
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Starter Control System Check
060R200062
Circuit Description
Starter control system is controlled by the Power Train
Control Module (PCM). The PCM monitors starter switch
signal (ªSTARTºposition ) and MODE switch (park or
neutral) signal. PCM is operated by the ignition switch.
Ignition feed voltage is supplied to the MODE switch and
starter relay through the engine fuse. PCM turns the
starter relay ªONº by grounding the starter relay driver
circuit.
The starter motor is operated until 30 seconds based on
starter relay signal.
Diagnostic Aids
An intermittent may be caused by the following:

Poor connections.

Mis routed harness.
Rubbed through wire insulation.

Broken wire inside the insulation.
Test Description
2.If Anti-theft system is ªONº, PCM does not operate
starter control system.
19.Refer to
6D section.
21.Refer to 6D section.
24.This vehicle is equipped with a PCM which utilizes
an electrically erasable programmable read only
memory (EEPROM). When the PCM is replaced,the
new PCM must be programmed.
Refer to
PCM Replacement and Programming
Procedures in Powertrain Control Module (PCM) and
Sensors.
Starter Control System Check

StepActionValue(s)Ye sNo
1Was the ªOn-Board (OBD) System Checkº performed?
ÐGo to Step 2
Go to OBD
System
Check
2Was the ªAnti-theft Systemº normally? Refer to
Owner's Manual.ÐGo to Step 3Go to Step 7

6E±97
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Starter Control System Check

 
StepNo Ye s Value(s) Action
31. Gear position is ªpark or neutralº.
2. Do not depress the accelerator pedal.
3. Turn the key to ªSTARTº position.
4. Release the key switch to the to ªONº position.
Does the engine crank?
ÐGo to Step 27Go to Step 4
41. Install the Tech 2.
2. Select ªDisplay DTCsº with the Tech 2.
Are any DTCs stored?
ÐGo to Step 5Go to Step 6
5Review and record for Tech 2 Failure Records data and
DTCs.
Were any DTCs information stored?
Ð
Go to DTCs
Chart
Ð
61. Gear position is ªpark or neutralº.
2. Do not depress the accelerator pedal.
3. Turn the key to ªSTARTº position.
Is the engine cranking?
ÐGo to Step 27Go to Step 7
7Check the anti±theft module circuit. Check the circuit
between PCM and anti±theft module.
Is the problem found?
ÐGo to Step 8Go to Step 9
8Repair the circuit as necessary.
Is the action complete?
ÐVerify repairÐ
91. Probe the anti-theft module circuit to GND.
2. Turn the key to ªSTARTº position.
Is the engine cranking?
ÐGo to Step 10Go to Step 11
10Check the anti-theft system. Refer to section 8H
anti-theft.
ÐVerify repairÐ
11Check the starter relay, starter fuse and engine fuse.
Is the problem found?
Go to Step 12Go to Step 13
12Replace the starter relay, starter fuse and engine fuse.
Is the action complete?
ÐVerify repairÐ
13Check the starter circuit.
1. Ignition is ºOFFº.
2. Remove the starter relay.
3. Check the circuit between starter relay and starter
motor.
Is the problem found?
ÐGo to Step 14Go to Step 15
14Repair the circuit as necessary.
Is the action complete?
ÐVerify repairÐ
15Check the starter circuit.
1. Remove the main fuse (100A).
2. Check the circuit between main fuse and starter
motor.
3. Check the circuit between GND and starter motor.
Is the problem found?
ÐGo to Step 16Go to Step 17

6E±98
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Starter Control System Check

 
StepNo Ye s Value(s) Action
16Repair the circuit as necessary.
Is the action complete?
ÐVerify repairÐ
17Check the starter signal circuit.
1. Remove the starter fuse (10A).
2. Disconnect the PCM.
3. Check the circuit between Powertrain Control
module (PCM) and starter fuse.
Is the problem found?
ÐGo to Step 18Go to Step 19
18Repair the circuit as necessary.
Is the action complete?
ÐVerify repairÐ
19Check the ªpark or neutralº signal circuit.
1. Remove the starter relay.
2. Disconnect the PCM.
3. Check the circuit between PCM and starter relay.
Is the problem found?
ÐGo to Step 20Go to Step 21
20Repair the circuit as necessary.
Is the action complete?
ÐVerify repairÐ
21Check the ªpark or neutralº signal circuit.
1. Remove the starter relay.
2. Disconnect the MODE switch.
3. Remove the engine (15A) fuse and back up (15A)
fuse.
4. Check the circuit between MODE switch and starter
relay.
5. Check the circuit between MODE switch and engine
fuse.
6. Check the circuit between MODE switch and PCM.
7. Check the circuit between MODE switch and back
up fuse.
Is the problem found?
ÐGo to Step 22Go to Step 23
22Repair the circuit as necessary.
Is the action complete?
ÐVerify repairÐ
23Check the MODE switch. Refer to 4L30E Automatic
transmission.
Is the problem found?Go to Step 24Go to Step 25
24Replace the MODE switch.
Is the action complete?
ÐVerify repairÐ
25Check the starter motor. Refer to Section 6D Engine
Electrical.
Is the problem found?Go to Step 26Go to Step 28
26Replace the starter motor.
Is the action complete?
ÐVerify repairÐ

6E±99
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Starter Control System Check

 
StepNo Ye s Value(s) Action
27Check the engine start times.
Is the engine start time less than specified value?
10 sec.System OK
Go to the
Engine
Cranks But
Will Not Run
Chart
28Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed.Refer to
ON-Vehicle Service in Power
ControlModule and Sensors
for procedures.And also
refer to latest Service Bulletin.Check to see if the latest
software is released ornot.
And then Down Load the LATEST PROGRAMMED
SOFTWARE to the replacement PCM.
Is the action complete?
ÐVerify repairÐ

6E±100
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Engine Cranks But Will Not Run
060R200083

6E±101
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
060R200075

6E±102
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Circuit Description
The electronic Ignition system uses a coil -at-plug method
of spark distribution. In this type of ignition system, the
powertrain control module (PCM) triggers the correct
driver outside the Ignition Current Sense System (ICSS),
which then triggers the correct ignition coil based on the
58X signal received from the crankshaft position sensor
(CKP). The spark plug connected to the coil fires when
the ICSS opens the ground circuit for the coil's primary
circuit.
During crank, the PCM monitors the CKP 58X signal. The
CKP signal is used to determine which cylinder will fire
first. After the CKP 58X signal has been processed by the
PCM, it will command all six injectors to allow a priming
shot of fuel for all the cylinders. After the priming, the
injectors are left ªOFFº during the next six 58X reference
pulses from the CKP. This allows each cylinder a chance
to use the fuel from the priming shot. During this waiting
been received by the PCM. The ION sensor signal allows
the PCM to operate the injectors sequentially based on
camshaft position. If the camshaft position signal is not
present at start - up, the PCM will begin sequential fuel
delivery with a 1 -in-6 chance that fuel delivery is correct.
The engine will run without a ION sensor signal, but will
set a DTC code.
Diagnostic Aids
An intermittent problem may be caused by a poor
connection, rubbed - through wire insulation or a wire
broken inside the insulation. Check for the following
items:

Poor connection or damaged harness-Inspect the
PCM harness and connectors for improper mating,
broken locks, improperly formed or damaged
terminals, poor terminal-to-wire connection, and
damaged harness.

Faulty engine coolant temperature sensor-Using a
Tech 2, compare engine coolant temperature with
intake air temperature on a completely cool engine.
Engine coolant temperature should be within 10
C of
intake air temperature. If not, replace the ECT sensor.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
5. An obvious cause of low fuel pressure would be an
empty fuel tank.
6. The engine will easily start and run if a few injectors
are disabled. It is not necessary to test all injectors
at this time since this step is only a test to verify that
all of the injectors have not been disabled by fuel
contamination.
7. A blinking test light verifies that the PCM is
monitoring the 58X crankshaft reference signal and
is capable of activating the injectors. If there is an
open or shorted driver circuit, DTCs 201 ± 206 and
a misfire DTC 300 ± 306 should be set.
19. By using a spark tester, each ignition coil's ability to
produce 25,000 volts is verified.
25. If there is an open or shorted driver circuit, DTCs
201 ± 206 and a misfire DTC 301 ± 306 should be
set. All six injector driver circuits can be checked at
one time without removing the intake manifold if a J
39021 ± 95 test light is available. This is the
alternative procedure:

With the ignition ªOFFº, disconnect the gray
connector located at the rear of the air filter, attached
to a bracket on the purge canister.

Connect test light J 39021 ± 95 to the connector. Do
any of the light constantly illuminate or fail to blink
when the engine is cranked? If so, repair the short or
open circuit, or replace the PCM if indicated.
This procedure only tests the driver circuit as far as the
test connection, so step 31 is added to test the circuit all
the way to the injector.
Engine Cranks But Will Not Run

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Check the ignition coil fuse, the engine fuse, and the
PCM fuse.
Was a fuse blown?
ÐGo to Step 3Go to Step 4
3Check for a short to ground and replace the fuse.
Is the action complete?
ÐVerify repairÐ

6E±103
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Engine Cranks But Will Not Run

 
StepNo Ye s Value(s) Action
41. Ignition ªOFFº, install a fuel pressure gauge at the
test fitting on the fuel supply line in the engine
compartment. (Use a shop cloth to absorb any fuel
leakage while making the connection.)
2. Ignition ªONº, observe the fuel pressure.
Is the fuel pressure within the specified values, and
does it hold steady?
285 - 375 kPa
(43 ± 55 psi)
Go to Step 6Go to Step 5
5Is any fuel pressure indicated?
Ð
Go to Fuel
System
Electrical TestGo to Fuel
System
Diagnosis
6Install the switch box J 39021±2 at the injector test
connector and activate an injector.
Did the fuel pressure drop when the injector was
activated?
ÐGo to Step 7Go to Step 18
7Install an injector test light at the #2 cylinder injector
harness connector.
Does the light blink when the engine is cranked?
ÐGo to Step 8Go to Step 24
81. Ignition ª OFFº.
2. Disconnect the 11-pin connector at the ION sensing
module.
3. With a test light to B + , probe each of the 6 exposed
ION sensing module pins, one at a time, while the
engine is cranked. (Use the gray narrow Metri - Pak
W flexible female connector from the J - 35616 kit to
make the pin accessible.)
Does the light flash at each pin when the engine is
cranked?
ÐGo to Step 12Go to Step 9
91. Remove the 4-pin connector at the ION sensing
module.
2. Ignition ª ONº.
3. Use a test light at the harness connector to verify
that the module is being supplied with B + and
ground.
Was a problem found?
ÐGo to Step 10Go to Step 11
10Repair the open ignition feed circuit or ground circuit to
the ION sensing module.
Is the action complete?
ÐVerify repairÐ
11Repair the ION sensing module.
Is the action complete?
ÐVerify repairÐ
121. Reconnect the ION sensing module 11-pin
connector.
2. Remove the electrical connector from each coil.
3. With a test light to B+, probe each of the coil
connectors at the wire which runs to the ION
sensing module.
Does the light flash at each coil connector when the
engine is cranked?
ÐGo to Step 14Go to Step 13
13Check for an open circuit between the coil and ION
sensing module.
Is the action complete?
ÐVerify repairÐ