Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 1271

6E1–160

RODEO Y22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

Diagnostic Aids

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
Bank 1 HO2S 1 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 Diagnostic Trouble Code P0133 cannot be duplicated,
reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how often

the condition that caused the Diagnostic Trouble Code 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:
2. Verifies that the fault is currently present.

3. HO2S transition time, ratio mean volts and

switching Diagnostic Trouble Codes set for multiple
sensors indicate probable contamination. Before
replacing the sensors, isolate and correct the source
of the contamination to avoid damaging the
replacement sensors.

DTC P0133 – O2 Sensor Circuit Slow Response (Bank 1 Sensor 1)

Step

Action

Value(s)

Yes

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

—

Go to Step 2

Go to OBD

System

Check

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

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

under ”Conditions for Setting the Diagnostic
Trouble Code” included in Diagnostic Support.

4. Using a Tech 2, monitor “Diagnostic Trouble Code”

info for Diagnostic Trouble Code P0133 until the
Diagnostic Trouble Code P0133 test runs.

5. Note the test result.

Does the Tech 2 indicate Diagnostic Trouble Code
P0133 failed this ignition?

—

Go to Step 3

Refer to

Diagnostic

Aids

Did the Tech 2 also indicate Diagnostic Trouble Code
P1133 and/or P1134 failed this ignition?

—

Go to Step 8

Go to Step 4

1. Perform ”Exhaust System Leak Test” (refer to

Exhaust System). After ”Exhaust System Leak
Test” has been performed, return to this diagnostic

2. If an exhaust leak is found, repair as necessary.

Was an exhaust leak isolated?

—

Go to Step 2

Go to Step 5

Visually/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?

—

Go to Step 9

Go to Step 6

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RODEO Y22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DTC P0133 – O2 Sensor Circuit Slow Response (Bank 1 Sensor 1)

(Cont'd)

Step

Yes

Value(s)

Action

1. Disconnect Bank 1 HO2S 1.
2. Ignition ON.
3. Using a Digital Voltmeter (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 7

Go to Step 10

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 12

Go to Step 13

Replace 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?

—

Verify repair

—

Repair condition as necessary.

Is the action complete?

—

Verify repair

—

Check for faulty PCM connections or terminal damage.

Is the action complete?

—

Verify repair

Go to Step 11

Repair open, short or grounded signal circuit.

Is the action complete?

—

Verify repair

—

Replace Bank 1 HO2S 1.

Is the action complete?

—

Verify repair

—

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

—

6E1–162

RODEO Y22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DIAGNOSTIC TROUBLE CODE (DTC)

P0134 O2 SENSOR CIRCUIT NO ACTIVITY DETECTED (BANK 1 SENSOR 1)

060R100030

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 M

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,
Diagnostic Trouble Code P0134 will be set, indicating an
open sensor signal or sensor low circuit. DTC P0134 is a
type B code.

Conditions for Setting the DTC

No related Diagnostic Trouble Codes.

Engine run time is longer than 120 seconds.

Engine Coolant Temperature (ECT) is above 60

(140

F).

Oxygen sensor heater has been determined to be
functioning properly, and the oxygen sensor has
warmed to operating temperature.

All the above conditions are met and the following
condition is met for 612 test failures in 720 test samples
(125 msec/test).

Bank 1 HO2S 1 signal voltage remains between 400
mV and 500 mV.

Action Taken When the DTC Sets

The PCM will illuminate the malfunction indicator lamp
(MIL) the second time the fault is detected.

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

”Open Loop” fuel control will be in effect.

Conditions for Clearing the MIL/DTC

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.

A history Diagnostic Trouble Code P0134 will clear
after 40 consecutive warm–up cycles have occurred
without a fault.

Diagnostic Trouble Code P0134 can be cleared by
using the Scan Tool’s ”Clear Info” function.

Diagnostic Aids

Check for the following conditions:

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.

Faulty HO2S heater or heater circuit – With the ignition
ON engine OFF after a cooldown period, the HO2S 1

6E1–163

RODEO Y22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

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.

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.

Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how often
the condition that caused the Diagnostic Trouble Code to
be set occurs. This may assist in diagnosing the
condition.

DTC P0134 – O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1)

Step

Action

Value(s)

Yes

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

—

Go to Step 2

Go to OBD

System

Check

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

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

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 “Diagnostic Trouble Code”

info for Diagnostic Trouble Code P0134 until the
Diagnostic Trouble Code P0134 test runs.

4. Note the test result.

Does the Tech 2 indicate Diagnostic Trouble Code
P0134 failed this ignition?

—

Go to Step 4

Refer to

Diagnostic

Aids

Check for a damaged harness.

Was a problem found?

—

Verify repair

Go to Step 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

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

1. Ignition OFF.
2. With the PCM disconnected, check continuity of the

Bank 1 HO2S 1 high circuit.

3. If the Bank 1 HO2S 1 high circuit measures over 0.5

, repair open or poor connection as necessary.

Was a Bank 1 HO2S 1 high circuit problem found and
corrected?

—

Verify repair

Go to Step 8

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