2002 ISUZU AXIOM turn signal

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±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±412
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P1153 HO2S Insufficient Switching Bank 2 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 thresholds. If the PCM
determines that the HO2S did not switch enough times,
DTC P1153 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

The engine is operating in ªclosed loopº,

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

The engine has been running for over 60 seconds.

Canister purge duty cycle is greater than 2%.

Engine speed is between 1500 RPM and 3000 RPM.
Mass air flow is between 8 g/second and 42 g/second.

Above conditions are present for a 3 seconds.

90 seconds after ªclosed loopº and stoichiometric
operation have been enabled, the PCM monitors the
oxygen sensor switching above and below 450 mV. If
fewer than 27 rich-to-lean and lean-to-rich switches for
Bank 2 HO2S 1 are detected, DTC P1153 will 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 P1153 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

DTC P1153 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.

6E±418
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1154 ± HO2S Transition Time Ratio Bank 2 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 2 HO2S 1 is securely
installed.

Check for corrosion on terminals.

Check 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?
ÐGo to Step 18Go to Step 15
151. Disconnect Bank 2 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 2 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 2 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 repairÐ

6E±427
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P1220 Throttle Position Senser2 (TPS2) Circuit Fault
D06RY00111
Circuit Description

The throttle position (TP2) sensor circuit provides a
voltage signal relative to throttle blade angle.
The TPS2 voltage will vary from about 8% (0.4V) to
about 92% (4.6V) at Wide Open Throttle (WOT) in
the specified voltage (about 5V).
This code detects a continuous short to ground or
high in either the circuit or the sensor.
Conditions for setting the DTC

The Ignition is ªONº.

The TPS2 output is more than 93.6 milliseconds, less
than 2.5% or more than 97.5% in the specified voltage
(5V).
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 P1120 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.

DTC P1120 can be cleared using the Tech2 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:

The MAP sensor shares a 5 Volt reference with the
Fuel Tank Pressure. If these codes are also set, it could
indicate a problem with the 5 Volt reference circuit.

The MAP sensor shares a ground with the Fuel Tank
Pressure, the ECT sensor, and the Transmission Fluid

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
TP sensor 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 P1120 cannot be duplicated, the

6E±428
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
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
P1120 Diagnostic Chart may isolate the cause of the
fault.
DTC P1220-TPS 2 Circuit Fault

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 not running.
2. Observe the MAP reading on the Tech 2.
Is the MAP reading less than the specified value?
65 kPaGo to Step 4Go to Step 7
41. 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 5V returns.)
ÐGo to Step 6Go to Step 5
51. Check the MAP signal circuit between the PCM and
MAP ground circuit.
2. If the MAP signal circuit is open or shorted, repair as
necessary.
Was the MAP signal circuit open or shorted?
ÐVerify repairGo to Step 13
6Replace the MAP sensor.
Is the action complete?
ÐVerify repairÐ
7Observe 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 TPS1
8±10 % TPS2
8±10 % WTO
TPS1 90±92
% TPS2
90±92 %
Refer to
Diagnostic
Aids
Go to Step 8
81. 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 9Go to Step 10
91. Connect a test light between the 5Volt reference
circuit and the TP2 sensor signal circuit at the TP
sensor harness connector.
2. Observe the TP sensor reading on the Tech 2.
Is the TP sensor reading near the specified value?
5VGo to Step 12Go to Step 11

6E±430
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnosis Trouble Code(DTC)
P1221 TPS1 ± TPS2 Correlation(Circuit Performance)
060R200069
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 DC
motor coil in duty (%) to adjustment the 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.

The accelerator position (AP) sensor circuit provides a
voltage signal relative to accelerator pedal angle.
The accelerator pedal angle (AP1) will vary from
about 13% at idle position to about 87% at open
throttle(WOT).
APS signal is used to determine which DC will adjust
throttle position.
After the APS signal has been processed by the
PCM, it will command the DC motor to move the
throttle position.

Accelerator pedal ± Check for objects blocking the AP
sensor or pedal arm with spring, and excessive
deposits in the accelerator pedal arm and on the
accelerator pedal.
Conditions for Setting the DTC

The ignition is ªONº.
A difference of between TPS1 and TPS2 correlation of
over 6.5% within 125 milliseconds.
Action Taken When the DTC Sets

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

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

A history DTC 1221 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.

DTC 1221 can be cleared 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:
2. Visually/physically inspect for the following throttle
valve conditions.
3.Visually/physically inspect for the following
accelerator pedal conditions.
5.Check the following circuits for throttle valve and DC
moter. Check the following TP sensor resistance
and DC motor.

6E±433
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1271 APS 1± 2 Correlation Error
060R200064
Circuit Description

The accelerator position (AP) sensor circuit provides a
voltage signal relative to accelerator pedal angle.
The accelerator pedal sensor (AP1) will vary from
about 13 % at idle position to about 87 % at wide
open throttle(WOT) to specified voltage (about 5V).
This code detects a correlation error between APS1
and APS2.
Conditions for setting the DTC

The Ignition is ªONº.

The accelerator pedal angle difference is more than 4.5
% between ASP1 and APS2 for more than 265
milliseconds.
Action Taken When the DTC Sets

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

The PCM will store conditions which were present
when the DTC was set as Failure Records only. This
information will not be stored as Freeze Frame 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 P1271 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.
DTC P1271 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.

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 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 P1271 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 DTCP1271 Diagnostic Chart may
isolate the cause of the fault.