ISUZU AXIOM 2002 Service Repair Manual

6E±474
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1404 EGR Stuck Closed
060R200050
Circuit Description
The powertrain control module (PCM) monitors the EGR
valve pintle position input to ensure that the valve
responds properly to commands from the PCM, and to
detect a fault if current pintle zero position is different from
the learned zero position. If the PCM detects a pintle
position signal indicates more than 30 % different
between current zero position and the learned zero
position for more than 5 seconds, and this condition exists
3 times during trip, then the PCM will set DTC P1404.
Conditions for Setting the DTC

Ignition voltage is between 11 and 16 volts.

Intake Air temp is more than 3
C.

Desired EGR position is more than 3 %.

Difference of EGR pintle position between current and
the learned zero is more than 30 % for more than 5
seconds, and exists three times to the above condition
during a trip the PCM will set DTC 1404. Then it trigger
the PCM light on.
Action Taken When the DTC Sets

The PCM will illuminate the malfunction indicator lamp
(MIL) after consecutive 2nd 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 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 P1404 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC P1404 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:

Excessive carbon deposit on EGR valve shaft and/or
foreign material may cause the EGR valve not to fully
seat. The carbon deposit may occur by unusual port
operation. Remove foreign material and/or excessive
carbon deposit on EGR valve shaft and to allow the
EGR valve to be fully seated.

Poor connection or damaged harness ± Inspect the
wiring harness for damage.
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.

6E±475
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1404 ± EGR Stuck Closed

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Ignition ªONº, engine ªOFFº, review and record
Tech 2 Failure Records Data.
2. Operate the vehicle within Failure Records
conditions as noted.
3. Using a Tech 2, monitor ªDTC inf.º for DTC P1404
until the DTC P1404 test runs. Note the result.
Does the Tech 2 indicates DTC P1404 failed this
ignition?
ÐGo to Step 3
Refer to
Diagnostic
Aids
31. Disconnect the EGR valve harness connector.
2. Inspect the EGR valve and connectors for damaged
pin or terminals.
Were there any damaged pins or terminals?
ÐGo to Step 4Go to Step 5
4Repair the damaged pin or terminal.
Is the action complete?
ÐVerify repairÐ
51. Remove EGR valve from Engine.
2. Inspect EGR valve for any excessive carbon
deposit on EGR shaft.
3. Inspect for any foreign material inside of EGR valve.
Was excessive carbon deposit on EGR valve shaft
and/or foreign material in EGR valve ?
ÐGo to Step 6Go to Step 7
61. Clean up EGR valve shaft and inside of EGR valve.
2. Remove foreign material from EGR valve.
3. Visually inspect damage of pintle and seat to see if it
is bent. If damaged, leakage may occur.
Was there any severe damage which affects function?
ÐGo to Step 9
Verify repair
Go to
Step 7
71. Install the EGR valve.
2. Ignition ªOFFº.
3. Install the Tech 2.
4. Run the engine at idle.
5. On the Tech 2, select EGR Control Test.
6. Use the ªUPº arrow to increase the EGR from 0% to
40%.
Did EGR work properly?
ÐVerify repairGo to Step 8
81. Reset the learned zero EGR valve position.
2. Repeat step 7.
Did EGR work properly?
ÐVerify repairGo to Step 9

6E±476
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1404 ± EGR Stuck Closed

 
StepNo Ye s Value(s) Action
9Replace the EGR valve.
Does DTC P1404 still fail ªDTCº test on the Tech 2?
ÐGo to Step 10Verify repair
10Replace 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±477
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P1441 EVAP System Flow During Non-Purge
060RY00398
Circuit Description
Canister purge is controlled by a solenoid valve that
allows manifold vacuum to purge the canister. The
powertrain control module (PCM) supplies a ground to
energize the solenoid valve (purge ªONº). The EVAP
purge solenoid control is pulse-width modulated (PWM)
or turned ªONº and ªOFFº several times a second. The
duty cycle (pulse width) is determined by engine
operating conditions including load, throttle position,
coolant temperature and ambient temperature. The duty
cycle is calculated by the PCM and the output is
commanded when the appropriate conditions have been
met.
Conditions for Setting the DTC

No active ECT sensor, IAT sensor, MAP sensor, or TP
sensor DTCs set.

BARO reading is above 85 kPa.

Engine coolant temperature is below 70
C (158
F).

Start-up intake air temperature (IAT) and start-up
engine coolant temperature (ECT) are both above 5
C
(41
F).

The difference between start-up ECT and start-up IAT
is less than 25
C (45
F).

TP sensor indicates a throttle position above 12%.

Battery voltage is between 11.5 volts and 16 volts.

Engine speed is between 800 and 6,000 RPM.

Canister purge duty cycle is below 3%.
Fuel level is between 15% and 85%.

All conditions are present for at least 3 seconds.
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 P1441 will clear after 40 consecutive
warm±up cycles have occurred without a fault.

DTC P1441 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 ± 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 wring harness for
damage. A change in the display will indicate the
location of the fault.

6E±478
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
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.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.3. Determines if the PCM is able to control the EVAP
purge solenoid valve.
4. Determines if the DTC will set under the conditions
present when the DTC was originally stored. If not,
the fault is intermittent.
5. Checks for a grounded EVAP purge solenoid driver
circuit, a faulty EVAP vacuum switch, or a leaking
EVAP purge solenoid valve.
DTC P1441 ± EVAP System Flow During Non-Purge

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.
2. Remove the fuel filler cap.
3. Ignition ªONº.
4. Observe ªFuel Tank Pressureº on the Tech 2.
Is ªFuel Tank Pressureº at the specified value?
1.51VGo to Step 3
Go to DTC
P0452 or
P0453
31. Re-install the fuel filler cap.
2. Using the Tech 2, command the EVAP Vent
Solenoid Valve ªONº (Closed).
3. Disconnect the canister side rubber hose end that
hose is connected between the Purge Solenoid
Valve and Canister.
IMPORTANT:Before continuing with the diagnosis,
zero the EVAP pressure/purge cart J41413 (refer to the
tool operating instructions).
And them monitor the fuel tank inner pressure using the
Tech 2.
Does the fuel tank pressure remain the specified
value?
1.52 - 1.60VGo to Step 4Go to Step 6
41. Disconnect the EVAP pressure/purge cart J41413,
and then plug the hose end.
2. Disconnect the rubber hose end of engine vacuum
source side, (the hose connected between Purge
Solenoid Valve and engine).
3. Connect the vacuum hand pump to this rubber hose
end.
4. Then apply the -15 in H2O vacuum by the vacuum
pump.
5. Monitor the fuel tank inner pressure using the Tech
2.
Does the fuel tank inner pressure hold the specified
value?
1.47 - 1.51VGo to Step 6Go to Step 5
5Replace the Purge Solenoid Valve.
ÐVerify RepairÐ

6E±479
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1441 ± EVAP System Flow During Non-Purge

 
StepNo Ye s Value(s) Action
61. Check leaks, kinks or pinched hoses at the EVAP
system rubber hose line, and also check if the
rubber hoses are correctly connected or not.
2. Check for a leak from Vent Solenoid Valve and
EVAP system rubber hoses, and also check for
clogged Filter of air separator which is located near
the vent solenoid valve.
Was a problem found? Using the Vacuum Hose
Routing Diagram, repair or re-connect the rubber
hoses correctly.
ÐVerify RepairGo to Step 7
71. Start engine.
2. Remove the Fuel Filler cap.
3. Using the Tech 2, command the EVAP Vent
Solenoid Valve ªONº (closed) and Purge Solenoid
Valve ªOFFº (0%).
4. Replace the Fuel Filler Cap.
5. Run the engine at 2500RPM constant while
monitoring ªFuel Tank Vacuumº on the Tech 2.
Does the fuel tank vacuum remain at the specified
value while the EVAP Vent Solenoid Valve ªONº
(closed) and Purge Solenoid Valve ªOFFº (0%)?
30 - 40 %Verify Repair
Go to
Diagnostic
Aids

6E±480
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1514 TPS - MAF Correlation Error
060R200061
Circuit Description

The throttle position (TP) sensor circuit provides a
voltage signal relative to throttle blade angle.
The throttle blade angle will vary from about 8 % at
closed throttle to about 92 % at wide open throttle
(WOT).

The mass air flow (MAF) sensor measures the amount
of air which passes through it into the engine during a
given time. The powertrain Control Module (PCM)
uses the mass air flow information to monitor engine
operating conditions for fuel delivery calculations.
A large quantity of air entering the engine indicates
an accelerator or high load situation, while a small
quantity or air indicates deceleration or idle.
The MAF sensor produces a frequency signal which
can be monitored using a Tech 2. The frequency will
vary within a range of around 4 to 7g/s at idle to
around 25 to 40g/s at maximum engine load.
Conditions for setting the DTC

The engine is running.

No MAF sensor DTCs are set.

Throttle actuation mode is not off.

MAF reading-ETC estimated air flow is less than 40g/s
for 250 failures within test 1000 test samples (15.6 m
sec).
Action Taken When the DTC Sets

The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.

The PCM calculates an air flow value based on idle air
control valve position, throttle position, RPM and
barometric pressure.

The PCM will store condition 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 conditions is no longer present.

A history DTC P1514 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.

DTC P1514 can be cleared using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
Diagnostic Aids
An intermittent may be caused by the following:

Poor connections.

Misrouted harness.

Rubbed through wire insulation.

Broken wire inside the insulation.
Check for the following conditions:

Poor connection at PCM - Inspect harness connectors
for backed out terminals, improper mating, broken

6E±481
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
locks, improperly formed or damaged terminals, and
poor terminal to wire connection.

Damaged harness - Inspect the wiring harness for
damage. If the harness appears to be OK, observe the
Mass Air Flow, TP sensor 1, TP sensor 2 display on the
Tech 2 while moving connectors and wiring harnesses
related to the sensor.

Plugged intake air duct or filter element

A wide - open throttle acceleration from a stop should
cause the mass air flow displayed on a Tech 2 to
increase from about 3 ± 6 g/s at idle to 100 g/s orgreater at the time of the 1 ± 2 shift. If not, check for a
restriction.
A change in the display will indicate the location of
the fault. If DTC P1514 cannot be duplicated, the
information included in the Failure Records data can
be useful in determining vehicle mileage since the
DTC was last set.
If it is determined that the DTC occurs intermittently,
performing the DTC P1514 Diagnostic Chart may
isolate the cause of the fault.
DTC P1514 - TPS-MAF Correlation Error

StepActionValue(s)Ye sNo
1Was the ªOn-Board (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. Ignition ªONº, engine ªOFFº.
2. Review and record Tech 2 Failure Records data.
3. Operate the vehicle within Failure Records
conditions as noted.
4. Using a Tech 2, monitor ªDTCº info for DTC P1514.
Does the Tech 2 indicate DTC P1514 failed this
ignition?
ÐGo to Step 4
Refer to
Diagnostic
Aids
41. Start the engine.
2. With the engine idling, monitor ªMAF Frequencyº
display on the Tech 2.
Is the ªMAF Frequencyº below the specified value?
6 ~ 10 g/sGo to Step 5Go to Step 8
51. Ignition ªOFFº.
2. Disconnect the MAF sensor connector.
3. Ignition ªONº, engine idling.
4. Using a Tech 2, monitor ªMAF Frequencyº.
Does the Tech 2 indicate a ªMAF Frequencyº at the
specified value?
0g/sGo to Step 6Go to Step 7
6Replace the MAF sensor.
Is the action complete?
ÐVerify repairGo to Step 9
71. Check the MAF harness for incorrect routing near
high voltage components (solenoids, relays,
motors).
2. If incorrect routing is found, correct the harness
routing.
Was a problem found?
ÐVerify repairGo to Step 19
81. With the engine idling, monitor ªMAF Frequencyº
display on the Tech 2.
2. Quickly snap open throttle to wide open throttle
while under a road load and record value.
Does the Tech 2 indicate a ªMAF Frequencyº at the
specified value?
6 ~ 10 g/sGo to Step 6Go to Step 9
91. IgnitionªONº, engine not running.
2. Observe the MAP reading on the Tech 2.
Is the MAP reading less than the specified value?
65kPaGo to Step 10Go to Step 13

6E±482
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1514 - TPS-MAF Correlation Error

 
StepNo Ye s Value(s) Action
101. Disconnect the MAP sensor.
2. Connect a test 5 volt reference circuit and the MAP
signal at the MAP sensor harness connector.
3. Observe the MAP reading on the Tech 2.
Is the MAP reading less than the specified value? (If no,
start with diagnosis chart for other sensors in the circuit
and see if 5Vreturns.)
ÐGo to Step 11Go to Step 12
111. Check the MAP signal circuit between the PCM and
MAP ground circuit.
2. If the MAP signal circuit is open or shorted, repair it
as necessary.
Was the MAP signal circuit open or shorted?
ÐVerify repairGo to Step 13
12Replace the MAP sensor.
Is the action complete?
ÐVerify repairÐ
13Observe the TP angle reading on the Tech 2 while
slowly opening the throttle.
Does the TP angle increase steadily and evenly from
the closed throttle value to the wide open throttle
value?Closed
throttle TP
sensor 1 =8 ~
10 % TP
sensor 2 =90
~ 92 % Wide
open throttle
TP sensor 1
=90 ~ 92 %
TP sensor 2
=8 ~ 10 %
Refer to
Diagnostic
Aids
Go to Step 14
141. Disconnect the TP sensor.
2. Observe the TP sensor reading on the Tech2.
Is the TP sensor reading near the specified value?
0VGo to Step 15Go to Step 16
151. Connect a test light between the 5Volt reference
circuit and the TP1 and TP2 sensor signal circuit at
the TP sensor harness connector.
2. Observe the TP sensor reading on the Tech2.
Is the TP sensor reading near the specified value?
5VGo to Step 18Go to Step 17
16Check the following items;
1. TP1 and TP2 signal circuit for a short to voltage.
2. TP1 and TP2 sensor ground circuit for high
resistance between the PCM and the TP sensor.
3. TP1 and TP2 sensor ground circuit for a poor
connection.
4. If a problem is found, repair wiring harness as
necessary.
Was a problem found?
ÐVerify repairGo to Step 19

6E±483
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1514 - TPS-MAF Correlation Error

 
StepNo Ye s Value(s) Action
17Check the following items;
1. TP1and TP2 signal circuit or 5 volt reference circuit
for a poor connection.
2. TP1 and TP2 signal circuit or 5 volt reference circuit
for high resistance between the PCM and the
TP1and TP2 sensor.
3. If a problem is found, repair wiring harness as
necessary.
Was a problem found?
ÐVerify repairGo to Step 18
18Replace the TP sensor.
Is the action complete?
ÐVerify repairÐ
19Replace 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