2002 ISUZU AXIOM engine

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±402
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

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. If the harness appears to be OK, observe the
AP sensor 1, AP sensor 2, AP sensor 3 display on the
Tech 2 while moving connectors and wiring harnesses
related to the sensor.A change in the display will indicate the location of
the fault.
If DTC P1125 cannot be duplicated, the information
included in the Failure Records data can be useful in
determined vehicle mileage since the DTC was last
set.
If it is determined that the DTC occurs intermittently,
performing the DTC P1125 Diagnostic Chart may
isolate the cause of the fault.
DTC P1125 ± ETC Limit Performance Model

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
3Observe the AP angle reading on the Tech 2 while
slowly opening the throttle.
Does the AP angle increase steadily and evenly from
the closed throttle value to the wide open throttle
value?Idle position
AP sensor 1
=13 % AP
sensor 2, 3
=85 ~ 89 %
open throttle
AP sensor 1
=85 ~ 89 %
AP sensor 2
=11 ~ 15 %
Refer to
Diagnostic
Aids
Go to Step 4
41. Disconnect the AP sensor.
2. Observe the AP sensor reading on the Tech 2.
Is the AP sensor reading near the specified value?
0VGo to Step 5Go to Step 6
51. Connect a test light between the 5 Voltage supply
circuit and the AP1, AP2 AND AP3 sensor signal
circuit at the AP sensor harness connector.
2. Observe the AP sensor reading on the Tech 2.
Is the AP sensor reading near the specified value?
5VGo to Step 7Go to Step 8
6Check the following items;
1. AP1, AP2 or AP3 signal circuit for a short to voltage.
2. AP1, AP2 or AP3 sensor ground circuit for high
resistance between the PCM and the AP sensor.
3. AP1, AP2 or AP3 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 9

6E±403
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1125 ± ETC Limit Performance Model

 
StepNo Ye s Value(s) Action
7Check the following items;
1. AP1, AP2 or AP3 signal circuit or 5 voltage supply
circuit for a poor connection.
2. AP1, AP2 or AP3 signal circuit or 5 voltage supply
circuit for high resistance between the PCM and the
AP1, AP2 or AP3 sensor.
3. If a problem is found, repair wiring harness as
necessary.
Was a problem found?
ÐVerify repairGo to Step 9
8Replace the AP sensor.
Is the action complete?
ÐVerify repairÐ
9Replace 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±404
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P1133 HO2S Insufficient Switching 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 enabled. During this test period the PCM counts the
number of times that the HO2S signal voltage crosses the
rich-to-lean and lean-to-rich threshold. If the PCM
determines that the HO2S did not switch enough times,
DTC P1133 will be set.
A lean-to-rich switch is determined when the HO2S
voltage changes above and below 450 mV.
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

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 9 g/second and 42
g/second.

Above conditions are present for 3 seconds.

90 seconds after ªclosed loopº and stoichiometric
operation have been achieved, the PCM monitors the
oxygen sensor as it switches above and below 450 mV.
If fewer than 23 rich-to-lean and lean-to-rich switches
are detected, DTC P1133 will be set.
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.

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 P1133 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC P1133 can be cleared by using Tech 2 ªClear Infoº
function or by disconnecting the PCM battery feed.

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±407
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1133 ± HO2S Insufficient Switching Bank 1 Sensor 1

 
StepNo Ye s Value(s) Action
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±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.