Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 286

6E–174

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

DTC P0133 – HO2S Slow Response Bank 1 Sensor 1

 

Step

Action

Value(s)

Yes

No

1

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to 

Step 2

Go to 

OBD

System

Check

2

NOTE: If any DTCs are set (expect P0153, P1133,
P1134, P1153, and/or P1154), refer to those DTCs
before proceeding with this diagnostic chart.

1. Install the Tech 2.
2. Idle the engine at normal operating temperature.
3. Operate the vehicle within parameters specified

under “Conditions for Setting the DTC” included in
Diagnostic Support.

4. Using a Tech 2, monitor “DTC” info for DTC P0133

until the DTC P0133 test runs.

5. Note the test result.

Does the Tech 2 indicate DTC P0133 failed this
ignition?

—

Go to 

Step 3

Refer to

Diagnostic

Aids

3

Did the Tech 2 also indicate DTC P0153, P1133,
P1134, P1153, and/or P1154 failed this ignition?

—

Go to 

Step 17

Go to 

Step 4

4

Check for leaks at the pipe joints.

Are the joints leaking?

—

Go to 

Step 5

Go to 

Step 6

5

Tighten the U–bolt nuts at the leaking joints.

Is the action complete?

—

Go to 

Step 2

—

6

Check for gaskets that are damaged or improperly
installed.

Are there damaged or misaligned gaskets?

—

Go to 

Step 7

Go to 

Step 8

7

1. Replace damaged gaskets.
2. Align the connections.
3. Tighten the connections.

Is the action complete?

—

Go to 

Step 2

—

8

Check for loose exhaust flange connections.

Are the flange connections loose?

—

Go to 

Step 2

Go to 

Step 10

9

Tighten the stud nuts or bolts to specifications.

Is the action complete?

—

Go to 

Step 2

—

10

Check for burned or corroded exhaust pipes.

Are the exhaust pipes burned or corroded?

—

Go to 

Step 11

Go to 

Step 12

11

Replace the exhaust pipes, as required.

Is the action complete?

—

Go to 

Step 2

—

12

Check for leaks at the exhaust manifold.

Are there leaks at the exhaust manifold?

—

Go to 

Step 13

Go to 

Step 14

13

Tighten the bolts to specifications to replace the
manifold if necessary.

Is the action complete?

—

Go to 

Step 2

—

6E–175

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

DTC P0133 – HO2S Slow Response Bank 1 Sensor 1

  (Cont'd)

Step

No

Yes

Value(s)

Action

14

Visually/physically inspect the following items:

D

Ensure that the Bank 1 HO2S 1 is securely
installed.

D

Check for corrosion on terminals.

D

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

D

Check for damaged wiring.

Was a problem found in any of the above areas?

—

Go to 

Step 18

Go to 

Step 15

15

1. Disconnect Bank 1 HO2S 1.
2. Ignition “ON”.
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 V

Go to 

Step 16

Go to 

Step 19

16

1. With Bank 1 HO2S 1 disconnected, jumper the high

and low (PCM side) signal circuits to ground.

2. Ignition “ON”.
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?

—

Go to 

Step 21

Go to 

Step 22

17

Replace the affected heated oxygen sensors.

NOTE: Before replacing sensors, the cause of the
contamination must be determined and corrected.

D

Fuel contamination.

D

Use of improper RTV sealant.

D

Engine oil/coolant consumption.

Is the action complete?

—

Verify repair

—

18

Repair condition as necessary.

Is the action complete?

—

Verify repair

—

19

Check for faulty PCM connections or terminal damage.

Is the action complete?

—

Verify repair

Go to 

Step 20

20

Repair open, short or grounded signal circuit.

Is the action complete?

—

Verify repair

—

21

Replace Bank 1 HO2S 1.

Is the action complete?

—

Verify repair

—

22

Replace 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?

—

Verify repair

—

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

D

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 “closed loop” 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.

D

Heated oxygen sensors are used to minimize the
amount of time required for “closed loop” 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.

D

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

D

No related DTCs.

D

Battery voltage is above 10 volts.

D

The engine has been running for over 5 seconds.

D

Engine coolant temperature (ETC) is above 60

°

C

(140

°

F).

D

Oxygen sensor heater has been determined to be
functioning properly.

D

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

D

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

D

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

D

“Open loop” fuel control will be in effect.

Conditions for Clearing the MIL/DTC

D

The PCM will turn the MIL “OFF” on the third
consecutive trip cycle during which the diagnostic has
been run and the fault condition is no longer present.

D

A history DTC P0134 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

D

DTC P0134 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the PCM battery
feed.

6E–177

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Aids

Check for the following conditions:

D

Poor connection or damaged harness – Inspect the
harness connectors for backed-out terminals,
improper mating, broken locks, improperly formed or
damaged terminals, poor terminal-to-wire connection,
and damaged harness.

D

Faulty HO2S heater or heater circuit – With the ignition
“ON”, engine “OFF”, after a cool down period, the
HO2S 1 voltage displayed on the Tech 2 is normally
455-460 mV.  A reading over 1000 mV indicates a
signal line shorted to voltage.  A reading under 5 mV
indicates a signal line shorted to ground or signal lines
shorted together.  Disconnect the HO2S and connect
a test light between the HO2S ignition feed and heater
ground circuits.  If the test light does not light for 2
seconds when the ignition is turned on, repair the open
ignition feed or sensor ground circuit as necessary.  If
the test light lights and the HO2S signal and low circuits
are OK, replace the HO2S.

D

Intermittent test – With the Ignition “ON”, monitor the
HO2S signal voltage while moving the wiring harness
and related connectors.  If the fault is induced, the
HO2S signal voltage will change.  This may help isolate
the location of the malfunction.

Test Description

Number(s) below refer to the step number(s) on the
Diagnostic Chart.
3. If the DTC P0134 test passes while the Failure

Records conditions are being duplicated, an
intermittent conditions is indicated.

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.

DTC P0134 –HO2S Circuit  Insufficient Activity Bank 1 Sensor 1

 

Step

Action

Value(s)

Yes

No

1

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to 

Step 2

Go to 

OBD

System

Check

2

1. Install the Tech 2.
2. Run the engine at operating temperature.
3. Operate the engine above 1200 RPM for two

minutes.

Does the Tech 2 indicate Bank 1 HO2S 1 voltage
varying outside the specified values?

400-500 mV

Go to 

Step 3

Go to 

Step 4

3

1. Ignition “ON”, engine “OFF”, review and record

Tech 2 Failure Records data and note parameters.

2. Operate the vehicle within Failure Records

conditions as noted.

3. Using a Tech 2, monitor “DTC” info for DTC P0134

until the DTC P0134 test runs.

4. Note the test result.

Does the Tech 2 indicate DTC P0134 failed this
ignition?

—

Go to 

Step 4

Refer to

Diagnostic

Aids

4

Check for a damaged harness.

Was a problem found?

—

Verify repair

Go to 

Step 5

5

Check for poor Bank 1 HO2S 1 high and low circuit
terminal connections at the Bank 1 HO2S 1 harness
connector and replace terminal(s) if necessary.

Did any terminals require replacement?

—

Verify repair

Go to 

Step 6

6

Check for poor Bank 1 HO2S 1 high and low circuit
terminal connections at the PCM and replace terminals
if necessary.

Did any terminals require replacement?

—

Verify repair

Go to 

Step 7