2002 ISUZU AXIOM relay

6E±84
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
No Malfunction Indicator Lamp (MIL)
060R200049
Circuit Description
The ªCheck Engineº lamp (MIL) should always be
illuminated and steady with the ignition ªONº and the
engine stopped. Ignition feed voltage is supplied to the
MIL bulb through the meter fuse. The powertrain control
module (PCM) turns the MIL ªONº by grounding the MIL
driver circuit.
Diagnostic Aids
An intermittent MIL may be cased by a poor connection,
rubbed-through wire insulation, or a wire broken inside
the insulation. Check for the following items:

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

If the engine runs OK, check for a faulty light bulb, an
open in the MIL driver circuit, or an open in the
instrument cluster ignition feed.

If the engine cranks but will not run, check for an open
PCM ignition or battery feed, or a poor PCM to engine
ground.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. A ªNo MILº condition accompanied by a no-start
condition suggests a faulty PCM ignition feed or
battery feed circuit.
9. Using a test light connected to B+, probe each of the
PCM ground terminals to ensure that a good ground
is present. Refer to
PCM Terminal End View for
terminal locations of the PCM ground circuits.
12.In this step, temporarily substitute a known good
relay for the PCM relay. The horn relay is nearby,
and it can be verified as ªgoodº simply by honking
the horn. Replace the horn relay after completing
this step.
17.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
Powertrain Control Module (PCM) and Sensors.

6E±85
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
No Malfunction Indicator Lamp (MIL)

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Attempt to start the engine.
Does the engine start?
ÐGo to Step 3Go to Step 6
3Check the meter fuse for the instrument cluster ignition
feed circuit.
Is the fuse OK?
ÐGo to Step 4Go to Step 16
4Ignition ªONº, probe the ignition feed circuit at the
cluster connector with a test light to ground.
Is the test light ªONº?
ÐGo to Step 5Go to Step 13
51. Ignition ªOFFº.
2. Disconnect the PCM.
3. Jumper the MIL driver circuit at the PCM connector
to ground.
4. Ignition ªONº.
Is the MIL ªONº?
ÐGo to Step 10Go to Step 11
6Check the PCM ignition feed and battery feed fuses (15
A engine fuse and 15 A PCM fuse).
Are both fuses OK?
ÐGo to Step 7Go to Step 15
71. Ignition ªOFFº.
2. Disconnect the PCM.
3. Ignition ªONº.
4. Probe the ignition feed circuit at the PCM harness
connector with a test light to ground.
Is the test light ªONº?
ÐGo to Step 8Go to Step 12
8Probe the battery feed circuit at the PCM harness
connector with a test light to ground.
Is the test light ªONº?
ÐGo to Step 9Go to Step 14
9Check for a faulty PCM ground connection.
Was a problem found?
ÐVerify repairGo to Step 10
10Check for damaged terminals at the PCM.
Was a problem found?
ÐVerify repairGo to Step 17
11Check for an open MIL driver circuit between the PCM
and the MIL.
Was a problem found?
ÐVerify repairGo to Step 18
12Substitute a known ªgoodº relay for the PCM main
relay.
Was the malfunction fixed?
ÐVerify repairGo to Step 13
13Repair the open in the ignition feed circuit.
Is the action complete?
ÐVerify repairÐ
14Locate and repair the open PCM battery feed circuit.
Is the action complete?
ÐVerify repairÐ

6E±89
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
No Reduced Power Lamp (RPL)
060R200073
Circuit Description
The Reduced Power lamp (RPL) should always be
illuminated and steady with the ignition ªONº and the
engine stopped. Ignition feed voltage is supplied to the
RPL bulb through the meter fuse. The powertrain control
module (PCM) orders the RPL ªONº signal for Multiplex
Control Unit. When Multiplex Control Unit is received RPL
ªONº signal that turn RPL ªONº by grounding the RPL
driver circuit.
Diagnostic Aids
An intermittent RPL may be caused by a poor connection,
rubbed-through wire insulation, or a wire broken inside
the insulation. Check for the following items:

Inspect the PCM and Multiplex Control Unit harness
and connections for improper mating, broken locks,
improperly formed or damaged terminals, poor
terminal to wire connection, and damaged harness.

If the engine runs OK, check for a faulty light bulb, an
open in the MIL driver circuit, or an open in the
instrument cluster ignition feed.

If the engine cranks but will not run, check for an open
PCM ignition or battery feed, or a poor PCM to engine
ground.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.2. A ªNo RPLº condition accompanied by a no±start
condition suggests a faulty PCM ignition feed or
battery feed circuit.
9. Using a test light connected to B+, probe each of the
Multiplex Control Unit ground terminals to ensure
that a good ground is present. Refer to Multiplex
Control Unit Terminal End View for terminal
locations of the Unit Terminal End View for terminal
locations of the Multiplex Control Unit ground
circuits.
12.Using a test light connected to B+, probe each of
the PCM ground terminals to ensure that a good
ground is present. Refer to PCM Terminal End View
for terminal locations of the PCM ground circuits.
21.In this step, temporarily substitute a known good
relay for the PCM relay. The horn relay is nearby,
and it can be verified as ªgoodº simply by honking
the horn. Replace the horn relay after completing
this step.
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.

6E±91
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
No Reduced Power Lamp (RPL)

 
StepNo Ye s Value(s) Action
121. Ignition ªOFFº.
2. Check for a faulty PCM ground connection and
Circuit.
Was a problem found?
ÐGo to Step 23Go to Step 13
13Check for damaged terminals at the PCM.
Was a problem found?
ÐGo to Step 24Go to Step 25
14Replace the fuse.
Is the action complete?
ÐVerify repairÐ
15Locate and repair the cluster meter battery feed open
circuit.
Is the action complete?
ÐVerify repairÐ
16Locate and repair the circuit between cluster meter and
Multiplex Control Unit open circuit.
Is the action complete?
ÐVerify repairÐ
17Locate and repair the circuit Multiplex Control Unit
battery feed open circuit.
Is the action complete?
ÐVerify repairÐ
18Locate and repair the between Multiplex Control Unit
and PCM open circuit.
Is the action complete?
ÐVerify repairÐ
19Locate and repair the ground connection for Multiplex
Control Unit circuit.
Is the action complete?
ÐVerify repairÐ
20Reconnect the Multiplex Control Unit. circuit.
Is the action complete?
ÐVerify repairÐ
21Substitute a known ªgoodº relay for the PCM main
relay.
Was the malfunction fixed?
ÐVerify repairGo to Step 22
22Repair the open in the ignition feed circuit.
Is the action complete?
ÐVerify repairÐ
23Locate and repair the ground connection for PCM
circuit.
Is the action complete?
ÐVerify repairÐ
24Replace 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?
ÐVerify repairÐ

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±108
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Circuit Description
When the ignition switch is first turned ªONº, the
powertrain control module (PCM) energizes the fuel
pump relay which applies power to the in-tank fuel pump.
The fuel pump relay will remain ªONº as long as the
engine is running or cranking and the PCM is receiving
58X crankshaft position pulses. If no 58X crankshaft
position pulses are present, the PCM de-energizes the
fuel pump relay within 2 seconds after the ignition is
turned ªONº or the engine is stopped.
The fuel pump delivers fuel to the fuel rail and injectors,
then to the fuel pressure regulator. The fuel pressure
regulator controls fuel pressure by allowing excess fuel to
be returned to the fuel tank. With the engine stopped and
ignition ªONº, the fuel pump can be turned ªONº by using a
command by the Tech 2.
Diagnostic Aids
An intermittent 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.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. If the fuel pump is operating but incorrect pressure is
noted, the fuel pump wiring is OK and the ªFuel
System Pressure Testº chart should be used for
diagnosis.
CAUTION: To reduce the risk of fire and personal
injury:

It is necessary to relieve fuel system pressure
before connecting a fuel pressure gauge. Refer to
Fuel Pressure Relief Procedure, below.

A small amount of fuel may be released when
disconnecting the fuel lines. Cover fuel line
fittings with a shop towel before disconnecting, to
catch any fuel that may leak out. Place the towel in
an approved container when the procedure is
completed.
Fuel Pressure Relief Procedure
1. Remove the fuel cap.
2. Remove the fuel pump relay from the underhood
relay center.
3. Start the engine and allow it to stall.
4. Crank the engine for an additional 3 seconds.
Fuel Gauge Installation
1. Remove the shoulder fitting cap.
2. Install fuel gauge J 34730-1 to the fuel feed line
located in front of and above the right side valve train
cover .
3. Reinstall the fuel pump relay.