2002 ISUZU AXIOM ignition

6E±401
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P1125 ETC (Electric Throttle Control) Limit Performance Mode
060R200064
Circuit Description

The accelerator position (AP1) sensor circuit provides
a voltage signal relative to accelerator pedal angle.
The accelerator pedal angle will vary about 13 % at
idle position to about 87 % at wide open throttle
(WOT).
This code detects if the system is in Limit
Performance Mode (Fail safe Mode) and Multiple
DTCs performance Mode.
Conditions for setting the DTC

The Ignition is ª ONº.

Limit Performance Mode is active. (Fail safe Mode)
Action Taken When the DTC Sets

The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.
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 condition is no longer present.

A history DTC P1125 will clear after 40 consecutive trip
cycle during which the warm up cycles have occurred
without a fault.

DTC P1125 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.

Mis routed harness.

6E±405
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Aids
A malfunction in the HO2S heater ignition feed or ground
circuit may cause a DTC P1133 to set. Check HO2S
heater circuitry for intermittent faults or poor connections.
If connections and wiring are OK and DTC P1133
continues to set, replace the Bank 1 HO2S 1.
Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help to 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. A condition that affects other heated oxygen sensors
indicates probable contamination. To avoid
damaging the replacement sensors, correct the
condition which caused the contamination before
replacing the affected sensors.
5. This step checks for conditions which may cause the
heated oxygen sensor to appear faulty. Correct any
of the described conditions if present.
11.To avoid damaging replacement sensors, correct the
condition which caused the contamination before
replacing the affected sensors.
DTC P1133 ± HO2S Insufficient Switching Bank 1 Sensor 1

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2IMPORTANT:If any DTCs are set (except P1153 or
P1154) refer to those DTCs before proceeding with this
diagnostic chart.
1. Engine idling at operating temperature.
2. Operating the vehicle within parameters specified
under ªConditions for Setting the DTCº criteria
included in Diagnostic Support.
3. Using a Tech 2, monitor ªDTCº info for DTC P1133
until the DTC P1133 test runs.
4. Note the test result.
Does the Tech 2 indicate DTC P1133 failed this
ignition?
ÐGo to Step 3
Refer to
Diagnostic
Aids
3Did the Tech 2 also indicate that the P1153 or P1154
tests failed?
ÐGo to Step 20Go to Step 4
4Check for leaks at the exhaust pipe joints.
Are the joints leaking?
ÐGo to Step 5Go to Step 6
5Tighten the bolt/nuts at the leaking joints.
Is your action complete?
ÐGo to Step 2Ð
6Check for gaskets that are damaged or improperly
installed.
Are there damaged or misaligned gaskets?
ÐGo to Step 7Go to Step 8
71. Replace the damaged gaskets.
2. Align the connections.
3. Tighten the connections.
Is your action complete?
ÐGo to Step 2Ð
8Check for loose exhaust flange connections.
Are the flange connections loose?
ÐGo to Step 9Go to Step 10
9Tighten the stud nuts or bolts to specifications.
Is your action complete?
ÐGo to Step 2Ð
10Check for burned or corroded exhaust pipes.
Are the exhaust pipes burned or corroded?
ÐGo to Step 11Go to Step 12

6E±406
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1133 ± HO2S Insufficient Switching Bank 1 Sensor 1

 
StepNo Ye s Value(s) Action
11Replace the exhaust pipes, as required.
Is your action complete?
ÐGo to Step 2Ð
12Check for leaks at the exhaust manifold.
Are there leaks at the exhaust manifold?
ÐGo to Step 13Go to Step 14
13Tighten the bolts to specifications or replace the
manifold if necessary.
Is your action complete?
ÐGo to Step 2Ð
14Visually/physically inspect the following items:

Ensure that the Bank 1 HO2S 1 is securely
installed.

Check for corrosion on the terminals.

Check the terminals at Bank 1 HO2S 1 and at the
PCM.

Check for damaged wiring.
Was a problem found in any of the above areas?
ÐVerify repairGo to Step 15
151. Disconnect Bank 1 HO2S 1.
2. Ignition ªONº.
3. Using a DVM at the PCM side of the connector,
check the voltage between the high signal circuit
and ground. Also measure between the low signal
circuit and ground.
Are both voltages in the specified range?
3-4 mVGo to Step 18Go to Step 16
161. Ignition ªOFFº.
2. Check for damage to PCM pins or terminals.
Was a problem found.
ÐVerify repairGo to Step 17
17Check for a short to voltage or ground or an open in the
signal circuit.
Was a problem found?
ÐVerify repairGo to Step 18
181. Ignition ªOFFº.
2. Disconnect the PCM connector.
3. With the HO2S disconnected, check for high and
low signal circuits shorted together between the
PCM and HO2S.
Was a problem found?
ÐVerify repairGo to Step 19
19With the PCM connected and Bank 1 HO2S 1
disconnected from the harness, check Bank 1 HO2S 1
with a Tech 2.
Is the voltage in the specified range?
425-475 mVGo to Step 21Go to Step 22
20Replace the affected heated oxygen sensors.
NOTE: Before replacing the 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

6E±408
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P1134 HO2S Transition Time Ratio Bank 1 Sensor 1
060R200054
Circuit Description
The powertrain control module (PCM) monitors the
heated oxygen sensor (HO2S) activity for 90 seconds
after ªclosed loopº and stoichiometric operation have
been established. During the monitoring period the PCM
counts the number of times that the HO2S responds from
rich-to-lean and from lean-to-rich and adds the amount of
time it took to complete all transitions. With this
information, an average time for all transitions can be
determined. The PCM then divides the rich-to-lean
average by the lean-to-rich average to obtain a ratio. If
the HO2S transition time ratio is not within this range,
DTC P1134 will be set, indicating that the oxygen sensor
is not responding as expected to changes in exhaust
oxygen content.
Conditions for Setting the DTC

No related DTCs.

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

Engine is operating in ªclosed loopº,

The engine has been running at least one minute.

Canister purge duty cycle is greater than 2%.

Engine speed is between 1500 RPM and 3000 RPM.

Mass air flow (MAF) is between 18 g/second and 42
g/second.

Above conditions are present for a 3-second
monitoring period.
90 seconds after ªclosed loopº and stoichiometric
operation have been enabled, Bank 1 HO2S 1
transition ratio between lean-to-rich and rich-to-lean is
less than 0.44 or greater than 3.8.
Action Taken When the DTC Sets

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

ºOpen loopº fuel control will be in effect.

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 P1134 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC P1134 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
Diagnostic Aids
A malfunction in the HO2S heater ignition feed or ground
circuit may cause a DTC P1134 to set. Check HO2S
heater circuitry for intermittent faults or poor connections.
If connections and wiring are OK and DTC P1134
continues to set, replace the Bank 1 HO2S 1.

6E±409
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. A condition that affects other heated oxygen sensors
indicates probable contamination. To avoid
damaging replacement sensors, correct the
condition which caused the contamination before
replacing the affected sensors.5. This step checks for conditions which may cause the
heated oxygen sensor to appear faulty. Correct any
of the described conditions if present.
8. To avoid damaging replacement sensors, correct the
condition which caused the contamination before
replacing the affected sensors.
DTC P1134 ± HO2S Transition Time Ratio Bank 1 Sensor 1

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2IMPORTANT:If any DTCs are set (except P1153
and/or P1154), refer to those DTCs before proceeding
with this diagnostic chart.
1. Idle the engine at operating temperature.
2. Operate the vehicle within parameters specified
under ªConditions for Setting the DTCº criteria
included in Diagnostic Support.
3. Using a Tech 2, monitor ªDTCº info for DTC P1134
until the DTC P1134 test runs.
4. Note the test result.
Does Tech 2 indicate DTC 1134 failed this ignition?
ÐGo to Step 3
Refer to
Diagnostic
Aids
3Did the Tech 2 also indicate P1153, and/or P1154 test
failed?
ÐGo to Step 17Go to Step 4
4Check for leaks at the exhaust pipe joints.
Are the joints leaking?
ÐGo to Step 5Go to Step 6
5Tighten the U-bolt nuts at the leaking joints.
Is your action complete?
ÐGo to Step 2Ð
6Check for gaskets that are damaged or improperly
installed.
Are there damaged or misaligned gaskets?
ÐGo to Step 7Go to Step 8
71. Replace the damaged gaskets.
2. Align the connections.
3. Tighten the connections.
Is your action complete?
ÐGo to Step 2Ð
8Check for loose exhaust flange connections.
Are the flange connections loose?
ÐGo to Step 9Go to Step 10
9Tighten the stud nuts or bolts to specifications.
Is your action complete?
ÐGo to Step 2Ð
10Check for burned or corroded exhaust pipes.
Are the exhaust pipes burned or corroded?
ÐGo to Step 11Go to Step 12
11Replace the exhaust pipes, as required.
Is your action complete?
ÐGo to Step 2Ð

6E±410
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1134 ± HO2S Transition Time Ratio Bank 1 Sensor 1

 
StepNo Ye s Value(s) Action
12Check for leaks at the exhaust manifold.
Are there leaks at the exhaust manifold?
ÐGo to Step 13Go to Step 14
13Tighten the bolts to specifications or replace the
manifold if necessary.
Is your action complete?
ÐGo to Step 2Ð
14Visually/physically inspect the following items:

Ensure that the Bank 1 HO2S 1 is securely
installed.

Check for corrosion on terminals.

Check the 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.
4. Also measure the voltage between the low signal
circuit and ground.
Are both voltages in the specified range?
3-4VGo 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 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 repairGo to Step 7

6E±413
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Aids
A malfunction in the HO2S heater ignition feed or ground
circuit may cause a DTC P1153 to set. Check HO2S
heater circuitry for intermittent faults or poor connections.
If connections and wiring are OK and DTC P1153
continues to set, replace the Bank 2 HO2S 1.
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. A condition that affects other heated oxygen sensors
indicates probable contamination. To avoid
damaging replacement sensors, correct the
condition which caused the contamination before
replacing the affected sensors.
5. This step checks for conditions which may cause the
heated oxygen sensor to appear faulty. Correct any
of the described conditions if present.
8. To avoid damaging replacement sensors, correct the
condition which caused the contamination before
replacing the affected sensors.
DTC P1153 ± HO2S Insufficient Switching Bank 2 Sensor 1

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2IMPORTANT:If any DTCs are set, (except P1133
and/or P1134), refer to those DTCs before proceeding
with this diagnostic chart.
1. Idle the engine at operating temperature.
2. Operate the vehicle within parameters specified
under ªConditions for Setting the DTCº criteria
included in Diagnostic Support.
3. Using a Tech 2, monitor ªDTCº info for DTC P1153
until the DTC P1153 test runs.
Note the test result.
Does Tech 2 indicate DTC failed this ignition?
ÐGo to Step 3
Refer to
Diagnostic
Aids
3Did the Tech 2 also indicate P1133 and/or P1134 test
failed?
ÐGo to Step 20Go to Step 4
4Check for leaks at the exhaust pipe joints.
Are the joints leaking?
ÐGo to Step 5Go to Step 6
5Tighten the U-bolt nuts at the leaking joints.
Is your action complete?
ÐGo to Step 2Ð
6Check for gaskets that are damaged or improperly
installed.
Are there damaged or misaligned gaskets?
ÐGo to Step 7Go to Step 8
71. Replace the damaged gaskets.
2. Align the connections.
3. Tighten the connections.
Is your action complete?
ÐGo to Step 2Ð
8Check for loose exhaust flange connections.
Are the flange connections loose?
ÐGo to Step 9Go to Step 10
9Tighten the stud nuts or bolts to specifications.
Is your action complete?
ÐGo to Step 2Ð
10Check for burned or corroded exhaust pipes.
Are the exhaust pipes burned or corroded?
ÐGo to Step 11Go to Step 12

6E±414
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1153 ± HO2S Insufficient Switching Bank 2 Sensor 1

 
StepNo Ye s Value(s) Action
11Replace the exhaust pipes, as required.
Is your action complete?
ÐGo to Step 2Ð
12Check for leaks at the exhaust manifold.
Are there leaks at the exhaust manifold?
ÐGo to Step 13Go to Step 14
13Tighten the bolts to specifications or replace the
manifold if necessary.
Is your action complete?
ÐGo to Step 2Ð
14Visually/physically inspect the following items:

Ensure that the Bank 2 HO2S 1 is securely
installed.

Check for corrosion on terminals.

Check the terminal tension at Bank 2 HO2S 1 and
at the PCM.

Check for damaged wiring.
Was a problem found in any of the above areas?
ÐVerify repairGo to Step 15
151. Disconnect Bank 2 HO2S 1.
2. Ignition ªONº.
3. Using a DVM at the PCM side of the connector,
check the voltage between the high signal circuit
and ground. Also measure between the low signal
circuit and ground.
Are both voltages in the specified range?
3-4VGo to Step 18Go to Step 16
161. Ignition ªONº.
2. Check for damage to PCM pins or terminals.
Was a problem found?
ÐVerify repairGo to Step 17
17Check for short to voltage or ground or an open in the
signal circuit.
Was a problem found?
ÐVerify repairGo to Step 18
181. Ignition ªOFFº.
2. Disconnect the PCM connector.
3. With HO2S disconnected, check for high and low
signal circuits shorted together between the PCM
and HO2S.
Was a problem found?
ÐVerify repairGo to Step 19
19With the PCM connected and Bank 2 HO2S 1
disconnected from the harness, check Bank 2 HO2S 1
with a Tech 2.
Is the voltage in the specified range?
425-475 mVGo to Step 21Go to Step 22
20Replace 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