engine ISUZU AXIOM 2002 Service Repair Manual

6E±353
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0502 VSS Circuit Low Input
060R200056
Circuit Description
The vehicle speed sensor has a magnet rotated by the
transmission output shaft. Attached to the sensor is a hall
effect circuit the interacts with the magnetic field treated
by the rotating magnet. A 12-volt operating supply for the
speed sensor hall circuit is supplied from the meter fuse.
The VSS pulses to ground the 9-volt signal sent from the
powertrain control module (PCM) on the reference circuit.
The PCM interprets vehicle speed by the number of
pulses to ground per second on the reference circuit.
Conditions for Setting the DTC

Engine is running.

Engine speed is between 1800 RPM and 2500 RPM.

Throttle angle is between 10% and 40%.

Engine load is greater than 50 kPa.

PCM detects no VSS signal for 12.5 seconds over a
period of 15 seconds.
Action Taken When the DTC Sets

The PCM will ON the MIL after second trip with
detected the fault.

The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for Clearing the MIL/DTC

The PCM will turn the MIL ªOFFº on the third
consecutive trip cycle during which the diagnostic has
been run and the fault condition is no longer present.

A history DTC P0502 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC P0502 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
10. To avoid backprobing the VSS and possibly
damaging a seal or terminal, the VSS output can be
tested at the point where the transmission harness
connects to the engine harness. Power and ground
are applied by jumpers to the VSS through the
connectors which are located to the rear of the air
cleaner assembly. The VSS signal is monitored
with a DVM as the rear driveshaft turns. The
wheels can be turned to rotate the driveshaft, or in
2-wheels-drive vehicles the driveshaft can be turned
directly.

6E±354
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0502 ± VSS Circuit Low Input

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Does the speedometer work?ÐGo to Step 10Go to Step 3
31. Disconnect the VSS connector.
2. Ignition ªONº.
3. Using a test light to battery +, probe the connector
ground wire.
Did the light illuminate?
ÐGo to Step 5Go to Step 4
4Repair the sensor ground.
Is the action complete?
ÐVerify repairÐ
51. Ignition ªONº, sensor disconnected.
2. Using a DVM, measure at the VSS connector
between ground and voltage supply.
Was the measurement near the specified value?
Battery
voltage
Go to Step 7Go to Step 6
6Repair the open or short to ground which may have
blown the meter fuse.
Is the action complete?
ÐVerify repairÐ
71. Ignition ªONº, VSS disconnected.
2. Using a DVM, measure at the VSS connector
between ground and the wire from the
speedometer.
Was the measurement near the specified value?
7.5-8 VGo to Step 9Go to Step 8
8Check for an open or short circuit between the
speedometer and the VSS.
Was an open or short circuit located?
ÐVerify repairGo to Step 9
9Replace the speedometer.
Is the action complete?
ÐVerify repairÐ

6E±355
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0502 ± VSS Circuit Low Input

 
StepNo Ye s Value(s) Action
101. Ignition ªOFFº.
2. Disconnect the MAF sensor. The connector
attaches the VSS wires from the transmission
harness to the left-side engine harness.
3. Disconnect the black 16-way connector.
4. Select a terminal adapter from kit J 35616 that can
be used with a jumper to supply B+ to the blue wire
with a yellow tracer (transmission side of the
connector).
5. Use another terminal adapter to attach a voltmeter
to the light-green wire with a white tracer (next to the
wire in the previous step.)
6. Disconnect the blue connector next to the black
16-way connector, and locate the black/red tracer
wire at one corner of the blue connector. The
black/red wire is the VSS ground. Use a terminal
adapter to attach a jumper to ground to the
black/red VSS ground wire at the transmission side
of the blue connector.
7. Raise the rear wheels off the ground with
transmission in neutral.
Does the DVM toggle back and forth between 0.6 V and
10 V as the wheels (and driveshaft) are rotated?
ÐGo to Step 11Go to Step 12
11Replace the VSS.
Is the action complete?
ÐVerify repairÐ
12Check for an open or short between the PCM and the
speedometer.
Was a problem found?
ÐVerify repairGo to Step 13
13Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
On-Vehicle Service in
Powertrain 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±356
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0506 Idle Air Control System Low RPM
060R200057
Circuit Description
The powertrain control module (PCM) controls engine
speed by adjusting the position of the throttle control
valve (DC motor). The throttle motor is a DC motor driven
by one coil. The PCM applies current to the DC motor coil
in position (%) to adjustment the throttle valve into a
passage in the throttle body to air flow. This method
allows highly accurate control of engine speed and quick
response to changes in engine load.
If the PCM detects a condition where too low of an idle
speed is present and the PCM is unable to adjust idle
speed by increasing the throttle position, DTC P0506 will
set, indicating a problem with the idle control system.
Conditions for Setting the DTC

No TPS, VSS, ECT, EGR, MAF, MAP, IAT, low voltage,
fuel system, canister purge, injector control, or ignition
control DTCs are set.

MAP is less than 60 kPa.

Canister purge duty cycle is above 10%.

Engine running time is more than 125 seconds.

Vehicle speed is less than 1 mph.

Engine coolant temperature (ECT) is above 50
C
(122
F).

Ignition voltage is between 9.5 volts and 16.7 volts.

The throttle is closed.

EVAP purge duty cycle more than 10%.

All conditions are met for 10 seconds.

Barometric pressure is more than 74.5 kPa.
Engine speed is more than 100-200 RPM lower than
desired idle based upon coolant temperature.
Action Taken When the DTC Sets

The PCM will illuminate the malfunction indicator lamp
(MIL) after the second consecutive trip in which the
fault is detected.

The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for Clearing the MIL/DTC

DTC P0506 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
Diagnostic Aids
Check for the following conditions:

Poor connection at PCM or throttle DC motor ± Inspect
harness connectors for backed-out terminals,
improper mating, broken locks, improperly formed or
damaged terminals, and poor terminal-to-wire
connection.

Damaged harness ± Inspect the wiring harness for
damage.

Restricted air intake system ± Check for a possible
collapsed air intake duct, restricted air filter element, or
foreign objects blocking the air intake system.

Throttle body ± Check for objects blocking the ETC
passage or throttle bore, excessive deposits in the

6E±357
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
ETC passage and on the ETC position, and excessive
deposits in the throttle bore and on the throttle plate.

Large vacuum leak ± Check for a condition that causes
a large vacuum leak, such as an incorrectly installed or
faulty PCV valve or brake booster hose disconnected.Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how often
the condition that caused the DTC to be set occurs. This
may assist in diagnosing the condition.
DTC P0506 ± Idle Air Control System Low RPM

StepActionValue(s)Ye sNo
1Was the ªOn-Board (OBD) System Checkº performed?
ÐGo to Step 2
Go to OBD
System
Check
2Visually/physically inspect for the following conditions:

Throttle body tampering.

Restricted intake throttle system. Check for a
possible collapsed air intake duct, restricted air
filter element, or foreign objects blocking the air
intake system.

Throttle body: Check for objects blocking the
throttle passage or throttle bore, excessive
deposits in the throttle passage and on the
throttle valve, and excessive deposits in the
throttle bore and on the throttle plate.

Throttle body with lever: Check for objects send
round the throttle spring lever that lever is smooth
movement, and spring lever has not excessive
play
Do any of the above require a repair?
Ð
Refer to
appropriate
section for
on±vehicle
service
Go to Step 3
3Visually/physically inspect for the following conditions:

Acceleration pedal tampering.

Acceleration pedal : Check for objects blocking
the spring or pedal arm.

Acceleration pedal : Check for objects move the
acceleration pedal that pedal is smooth
movement, and acceleration pedal arm has not
excessive play.
Do any of the above require a repair?
Ð
Refer to
appropriatese
ction for
on-vehicle
service
Go to Step 4
41. Check for a poor connection at the throttle body
harness connector.
2. Check for a poor connection at the acceleration
position sensor harness connector.
3. If a problem is found, replace faulty terminals as
necessary.
Was a problem found?
ÐVerify repairGo to Step 7
5Check the following circuits for an open, short to
voltage, short to ground, or poor connection at the
PCM:

Throttle position sensor 1 circuit.

Throttle position sensor 2 circuit.

Throttle DC motor circuit.

Throttle position sensor resistance.

Throttle DC motor resistance.

If a problem is found, repair as necessary.
Was a problem found?
Vcc-GND
1±7k

SIG-DND
change
resistance0.3
± 100

Verify repairGo to Step 6

6E±358
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0506 ± Idle Air Control System Low RPM

 
StepNo Ye s Value(s) Action
6Replace the throttle valve.
Is the action complete?
ÐGo to Step 3Ð
71. Check the following circuits for an open, short to
voltage, short to ground, or poor connection at the
PCM:
Accelerator position sensor 1 circuit.
Accelerator position sensor 2 circuit.
Sensor resistance.
2. If a problem is found, repair as necessary.
Was a problem found?
Vcc-GND
4±6k

SIG-DND
change
resistance
Verify repairGo to Step 8
8Replace the acceleration position sensor.
Is the action complete?
ÐGo to Step 9Ð
9Following below the DTCs stored: P1125, P1290,
P1295, P1299
Ð
Go to
applicable
DTC table
Go to Step 10
10Following below the DTCs stored:P1514, P1515,
P1516, P1523, P1271, P1272, P1273
Ð
Go to
applicable
DTC table
Go to Step 11
11Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
On-Vehicle Service in
Powertrain 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±359
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P0507 Idle Air Control System High RPM
060R200057
Circuit Description
The powertrain control module (PCM) controls engine
speed by adjusting the position of the throttle control
valve (DC motor). The throttle motor is a DC motor driven
by one coil. The PCM applies current to the DC motor coil
in position (%) to adjustment the throttle valve into a
passage in the throttle body to air flow. This method
allows highly accurate control of engine speed and quick
response to changes in engine load.
If the PCM detects a condition where too high of an idle
speed is present and the PCM is unable to adjust idle
speed by increasing the throttle position, DTC P0507 will
set, indicating a problem with the idle control system.
Conditions for Setting the DTC

No TPS, VSS, ECT, EGR, MAF, MAP, IAT, low voltage,
fuel system, canister purge, injector control or ignition
control DTCs are set.

Barometric pressure is above 75 kPa.

Canister purge duty cycle is above 10%.

Engine running time is more than 125 seconds.

Vehicle speed is less than 1 mph.

Engine coolant temperature (ECT) is above 50
C
(122
F).

Ignition voltage is between 9.5 volts and 16.7 volts.

The throttle is closed.

EVAP purge duty cycle is more than 10%.
All conditions are met for 10 seconds.

Engine speed is more than 100-200 RPM higher than
desired idle based upon coolant temperature.

Barometric pressure is more than 74.5 kPa.
Action Taken When the DTC Sets

The PCM will illuminate the malfunction indicator lamp
(MIL) after the second consecutive trip in which the
fault is detected.

The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for Clearing the MIL/DTC

The PCM will turn the MIL ªOFFº on the third
consecutive trip cycle during which the diagnostic has
been run and the fault condition is no longer present.

A history DTC P0507 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC P0507 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
Diagnostic Aids
Check for the following conditions:

Poor connection at PCM or throttle DC motor ± Inspect
harness connectors for backed-out terminals,
improper mating, broken locks, improperly formed or

6E±360
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
damaged terminals, and poor terminal-to-wire
connection.

Damaged harness ± Inspect the wiring harness for
damage.

Vacuum leak ± Check for a condition that causes a
vacuum leak, such as disconnected or damaged
hoses, leaks at EGR valve and EGR pipe to intake
manifold, leak at the throttle body, a faulty or incorrectly
installed PCV valve, leaks at the intake manifold, etc.
Throttle body ± Check for sticking throttle plate. Also
inspect the air passage for deposits or objects which
will not allow the ETC position to fully extend or
properly seat.
If DTC P0507 cannot be duplicated, reviewing the Failure
Records vehicle mileage since the diagnostic test last
failed may help determine how often the condition that
caused the DTC to be set occurs. This may assist in
diagnosing the condition.
DTC P0507 ± Idle Air Control System High RPM

StepActionValue(s)Ye sNo
1Was the ªOn-Board (OBD) System Checkº performed?
ÐGo to Step 2
Go to OBD
System
Check
2Visually/physically inspect for the following conditions:

Throttle body tampering.

Restricted intake throttle system. Check for a
possible collapsed air intake duct, restricted air
filter element, or foreign objects blocking the air
intake system.

Throttle body: Check for objects blocking the
throttle passage or throttle bore, excessive
deposits in the throttle passage and on the
throttle valve, and excessive deposits in the
throttle bore and on the throttle plate.

Throttle body with lever: Check for objects send
round the throttle spring lever that lever is smooth
movement, and spring lever has not excessive
play
Do any of the above require a repair?
Ð
Refer to
appropriate
section for
on-vehicle
service
Go to Step 4
3Visually/physically inspect for the following conditions:

Accelerator pedal tampering.

Accelerator pedal : Check for objects blocking the
spring or pedal arm.

Accelerator pedal : Check for objects move the
accelerator pedal that pedal is smooth
movement, and accelerator pedal arm has not
excessive play.
Do any of the above require a repair?
Ð
Refer to
appropriate
section for
on-vehicle
service
Go to Step 4
41. Check for a poor connection at the throttle body
harness connector.
2. Check for a poor connection at the accelerator
position sensor harness connector.
3. If a problem is found, replace faulty terminals as
necessary.
Was a problem found?
ÐVerify repairGo to Step 7

6E±361
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0507 ± Idle Air Control System High RPM

 
StepNo Ye s Value(s) Action
5Check the following circuits for an open, short to
voltage, short to ground, or poor connection at the
PCM:

Throttle position sensor 1 circuit.

Throttle position sensor 2 circuit.

Throttle DC motor circuit.

Throttle position sensor resistance.

Throttle DC motor resistance.

If a problem is found, repair as necessary.
Was a problem found?
Vcc-GND
1±7k

SIG-GND
change
resistance 0.3
± 100

Verify repairGo to Step 6
6Replace the throttle valve.
Is the action complete?
ÐGo to Step 3Ð
71. Check the following circuits for an open, short to
voltage, short to ground, or poor connection at the
PCM:

Accelerator position sensor 1 circuit.

Accelerator position sensor 2 circuit.

Sensor 3 circuit.

Sensor resistance.
2. If a problem is found, repair as necessary.
Was a problem found?
Vcc-GND
4±6k

SIG-GND
change
resistance
Verify repairGo to Step 8
8Replace the accelerator position sensor.
Is the action complete?
ÐGo to Step 9Ð
9Stored DTCs: P1125, P1290, P1295, P1299
Ð
Go to
applicable
DTC table
Go to Step 10
10Stored DTCs: P1514, P1515, P1516, P1523, P1271,
P1272, P1273
Ð
Go to
applicable
DTC table
Go to Step 11
11Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
On-Vehicle Service in
Powertrain 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±362
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0562 System Voltage Low
060R200058
Circuit Description
The powertrain control module (PCM) monitors the
system voltage on the ignition feed terminal to the PCM.
A system voltage DTC will set whenever the voltage is
below a calibrated value.
Conditions for Setting the DTC

Ignition ªONº.

System voltage is below 11.5 volts for 40 seconds.
Action Taken When the DTC Sets

The PCM will not illuminate the malfunction indicator
lamp (MIL).

The PCM will store as Failure Records conditions
which were present when the DTC was set. This
information will not be stored as Freeze Frame data.
Conditions for Clearing the MIL/DTC

A history DTC P0562 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC P0562 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
Diagnostic Aids
If the DTC sets when an accessory is operated, check for
a poor connection or excessive current draw.