2002 ISUZU AXIOM engine coolant

6E±163
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0125 ±ECT Excessive Time to Closed Loop Fuel Control

 
StepNo Ye s Value(s) Action
6Compare engine coolant temperature displayed on the
Tech 2 to the actual coolant temperature measured
with a thermometer. (Observe normal precautions
when opening the cooling system.)
Is the Tech 2 engine coolant temperature indication
close to the measured temperature?
ÐGo to Step 9Go to Step 7
71. Ignition ªOFFº.
2. Disconnect the PCM.
3. Using a DVM, measure the resistance of the ECT at
the PCM connector.
4. Compare the DVM reading with the chart in ªTest
Descriptionº.
Is the chart value approximately equal to the
thermometer reading?
ÐGo to Step 12Go to Step 8
8Check for high resistance in wiring related to the ECT
sensor. Also, check for poor connections at the ECT
sensor and the PCM.
Was a problem found?
ÐGo to Step 10Go to Step 11
9Refer to Cooling and Radiator for cooling system
diagnosis and repair condition as necessary.
Is the action complete?
ÐVerify repairÐ
10Replace the faulty terminal(s) or repair faulty wiring as
necessary.
Is the action complete?
ÐVerify repairÐ
11Replace the ECT sensor.
Is the action complete?
ÐVerify repairÐ
12Replace 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±164
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code(DTC)
P0128 Thermostat Insufficient Temperature for Stable Operation
060R200053
Circuit Description

The engine coolant temperature (ECT) sensor
thermistor mounted on a coolant crossover pipe at the
front of the engine.
This code determines if system has insufficient
coolant temperatures for stable operation.
Conditions for setting the DTC

Engine running.

No IAT, ECT and MAF DTCs set.

No VSS DTC set.
Warm case(Ambient temperature is between 50
F and
128
F.):

Time for coolant to reach stabilized closed loop value
is less than 239 sec.
Cold case(Ambient temperature is between 20
F and
50
F.):

Time for coolant to reach stabilized thermostat
regulation temperature is more than 263 sec.
Action Taken When the DTC Sets

The PCM will ON the MIL after second trip with
detected 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 P0128 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.

DTC P0128 can be cleared using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
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
locks, improperly formed or damaged terminals, and
poor terminal to wire connection.

Damaged harness±Inspect the wiring harness for
damage.

6E±166
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P0131 HO2S Circuit Low Voltage Bank 1 Sensor 1
060R200054
Circuit Description
The powertrain control module (PCM) supplies a bias
voltage of about 450 mV between the heated oxygen
sensor (HO2S) signal high and signal low circuits. When
measured with a 10 megaohm digital voltmeter, this may
display as low as 350 mV. The oxygen sensor varies the
voltage within a range of about 1000 mV when the
exhaust is rich, down through about 10 mV when exhaust
is lean. The PCM constantly monitors the HO2S signal
during ªclosed loopº operation and compensates for a rich
or lean condition by decreasing or increasing injector
pulse width as necessary. If the Bank 1 HO2S 1 voltage
remains excessively low for an extended period of time,
DTC P0131 will be set.
Conditions for Setting the DTC

No related DTCs.

Vehicle is operating in ªclosed loopº.

Engine coolant temperature is above 60
C (140
F).

ªClosed loopº commanded air/fuel ratio is between
14.5 and 14.8.

Bank 1 HO2S 1 signal voltage remains below 22 mV
during normal ªclosed loopº operation for a total of 77
seconds over a 90-second period of time.
Action Taken When the DTC Sets

The PCM will ON the MIL after second trip with
detected fault.
The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.

ªOpen loopº fuel control will be in effect.
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 P0131 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC P0131 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:

Heated oxygen sensor wiring ± The sensor pigtail may
be routed incorrectly and contacting the exhaust
system.

Poor PCM to engine block grounds.

Fuel pressure ± The system will go lean if pressure is
too low. The PCM can compensate for some
decrease. However, If fuel pressure is too low, a DTC
P0131 may be set. Refer to
Fuel System Diagnosis.

Lean injector(s) ± Perform ªInjector Balance Testº.

Vacuum leaks ± Check for disconnected or damaged
vacuum hoses and for vacuum leaks at the intake
manifold, throttle body, EGR system, and PCV system.

6E±169
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P0132 HO2S Circuit High Voltage Bank 1 Sensor 1
060R200054
Circuit Description
The powertrain control module (PCM) supplies a bias
voltage of about 450 mV between the heated oxygen
sensor (HO2S) signal and low circuits. When measured
with a 10 megaohm digital voltmeter, this may display as
low as 320 mV. The oxygen sensor varies the voltage
within a range of about 1000 mV when exhaust is rich,
down through about 10 mV when exhaust is lean. The
PCM constantly monitors the HO2S signal during ªclosed
loopº operation and compensates for a rich or lean
condition by decreasing or increasing injector pulse width
as necessary. If the Bank 1 HO2S 1 voltage remains
excessively high for an extended period of time, DTC
P0132 will be set.
Conditions for Setting the DTC

No related DTCs.

Engine coolant temperature is above 60
C (140
F)

ªClosed loopº commanded air/fuel ratio is between
14.5 and 14.8.

Bank 1 HO2S 1 signal voltage remains above 952 mV
during normal ªclosed loopº operation for a total of 77
seconds over a 90-second period.
OR

Bank 1 HO2S 1 signal voltage remains above 500 mV
during ªdeceleration fuel cutoff modeº operation for 3
seconds.
Action Taken When the DTC Sets

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

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

ªOpen loopº fuel control will be in effect.
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 P0132 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC P0132 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
Diagnostic Aids
Check the following items:

Fuel pressure ± The system will go rich if pressure is
too high. The PCM can compensate for some
increase. However, if fuel pressure is too high, a DTC
P0132 may be set. Refer to
Fuel System Diagnosis.

Perform ªInjector Balance Testº ± Refer to
Fuel System
Diagnosis.

6E±172
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P0133 HO2S Slow Response Bank 1 Sensor 1
060R200054
Circuit Description
The powertrain control module (PCM) continuously
monitors the heated oxygen sensor (HO2S) activity for 90
seconds after ªclosed loopº has been enabled. During the
monitoring period the PCM counts the number of times
that a rich-to-lean and lean-to-rich response is indicated
and adds the amount of time it took to complete all
rich-to-lean transitions and lean-to-rich transitions. With
this information, an average time for rich-to-lean and
lean-to-rich transitions can be determined. If the average
response time of either transition is too slow, a DTC
P0133 will be set.
A lean-to-rich transition is indicated when the HO2S
voltage changes from less than 300 mV to greater than
600 mV. A rich-to-lean transition is indicated when the
HO2S voltage changes from more than 600 mV to less
than 300 mV. An HO2S that responds too slowly is likely
to be faulty and should be replaced.
Conditions for Setting the DTC

No related DTCs.

Engine coolant temperature (ETC) is above 60
C
(140
F).

Engine is operating in ªclosed loopº.

Engine has been running for at least 90 seconds.

Engine speed is between 1500 RPM and 3000 RPM.

Canister purge duty cycle is greater than 2%.
Mass air flow is between 18 g/second and 42 g/second.

All above conditions are met for 3 seconds.

90 seconds after ªclosed loopº has been enabled,
Bank1 HO2S 1 average transition time between
300 mV and 600 mV is too slow. The lean-to-rich
average transition response time was longer than 94
milliseconds or rich-to-lean average transition
response time was longer than 105 milliseconds.
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.

ªOpen loopº fuel control will be in effect.
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 P0133 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC P0133 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.

6E±175
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0133 ± HO2S Slow Response Bank 1 Sensor 1

 
StepNo Ye s Value(s) Action
14Visually/physically inspect the following items:

Ensure that the Bank 1 HO2S 1 is securely
installed.

Check for corrosion on terminals.

Check terminal tension (at Bank 1 HO2S 1 and at
the PCM).

Check for damaged wiring.
Was a problem found in any of the above areas?
ÐGo to Step 18Go to Step 15
151. Disconnect Bank 1 HO2S 1.
2. Ignition ªONº.
3. Using a DVM at the PCM side of the HO2S 1
connector, measure the voltage between the high
signal circuit and ground. Also measure the voltage
between the low signal circuit and ground.
Are both voltages in the specified range?
3-4 VGo to Step 16Go to Step 19
161. With Bank 1 HO2S 1 disconnected, jumper the high
and low (PCM side) signal circuits to ground.
2. Ignition ªONº.
3. Using a Tech 2, monitor the Bank 1 HO2S 1 voltage.
Does the Tech 2 indicate less than 10 mV and
immediately return to about 450 mV when the jumper is
removed?
ÐGo to Step 21Go to Step 22
17Replace the affected heated oxygen sensors.
NOTE: Before replacing sensors, the cause of the
contamination must be determined and corrected.

Fuel contamination.

Use of improper RTV sealant.

Engine oil/coolant consumption.
Is the action complete?
ÐVerify repairÐ
18Repair condition as necessary.
Is the action complete?
ÐVerify repairÐ
19Check for faulty PCM connections or terminal damage.
Is the action complete?
ÐVerify repairGo to Step 20
20Repair open, short or grounded signal circuit.
Is the action complete?
ÐVerify repairÐ
21Replace Bank 1 HO2S 1.
Is the action complete?
ÐVerify repairÐ
22Replace 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±176
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P0134 HO2S Circuit Insufficient Activity Bank 1 Sensor 1
060R200054
Circuit Description

The powertrain control module (PCM) supplies a bias
voltage of about 450 mV between the heated oxygen
sensor (HO2S) high and low circuits. When measured
with a 10 megaohm digital voltmeter, this may display
as low as 320 mV. The oxygen sensor varies the
voltage within a range of about 1000 mV when the
exhaust is rich, down through about 10 mV when
exhaust is lean. The PCM constantly monitors the
HO2S signal during ªclosed loopº operation and
compensates for a rich or lean condition by decreasing
or increasing injector pulse width as necessary. If the
Bank 1 HO2S 1 voltage remains at or near the 450 mV
bias for an extended period of time, DTC P0134 will be
set, indicating an open sensor signal or sensor low
circuit.

Heated oxygen sensors are used to minimize the
amount of time required for ªclosed loopº fuel control
operation and to allow accurate catalyst monitoring.
The oxygen sensor heater greatly decreases the
amount of time required for fuel control sensors Bank
1 HO2S 1 and Bank 2 HO2S 1 to become active.

Oxygen sensor heaters are required by post-catalyst
monitor sensors to maintain a sufficiently high
temperature for accurate exhaust oxygen content
readings further from the engine.
Conditions for Setting the DTC

No related DTCs.

Battery voltage is above 10 volts.
The engine has been running for over 5 seconds.

Engine coolant temperature (ETC) is above 60
C
(140
F).

Oxygen sensor heater has been determined to be
functioning properly.

Bank 1 HO2S 1 signal voltage remains between
400 mV and 500 mV for a total of 77 seconds over a
90-second period of time.
Action Take When the DTC Sets

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

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

ªOpen loopº fuel control will be in effect.
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 P0134 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC P0134 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.

6E±179
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P0135 HO2S Heater Circuit Bank 1 Sensor 1
060R200054
Circuit Description
Heated oxygen sensors are used to minimize the amount
of time required for ªclosed loopº fuel control operation
and to allow accurate catalyst monitoring. The oxygen
sensor heater greatly decreases the amount of time
required for fuel control sensors Bank 1 HO2S 1 and Bank
2 HO2S 1 to become active. Oxygen sensor heaters are
required by post-catalyst monitor sensors to maintain a
sufficiently high temperature which allows accurate
exhaust oxygen content readings further from the engine.
The powertrain control module (PCM) will run the heater
test only after a cold start (determined by engine coolant
and intake air temperature at the time of start-up) and only
once during an ignition cycle. When the engine is started
the PCM will monitor the HO2S voltage. When the HO2S
voltage indicates a sufficiently active sensor, the PCM
looks at how much time has elapsed since start-up. If the
PCM determines that too much time was required for the
Bank 1 HO2S 1 to become active, a DTC P0135 will set.
The time it should take the HO2S to reach operating
temperature is based on the accumulated amount of air
that has passed through the MAF sensor and into the
engine (more accumulated air flow = shorter time to
HO2S activity).
Conditions for Setting the DTC

The engine has been running for over 120 seconds.

Heater signal is below 0.1A.

Bank 1 HO2S 1 voltage does not change more than
150 mV from the bias voltage (between 400 mV and
500 mV) for a longer amount of time than it should. The
maximum amount of time to come up to operating
range is 150 seconds. This warm-up time depends on
the engine coolant temperature at start-up and
accumulate air flow since start-up.
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 P0135 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC P0135 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.