Isuzu Rodeo UE. Manual — part 238

6E1–323

RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DIAGNOSTIC TROUBLE CODE (DTC) P1134 O2 SENSOR TRANSITION TIME

RATIO (BANK 1 SENSOR 1)

D06RX046

Circuit Description

The powertrain control module (PCM) monitors the
heated oxygen sensor (HO2S) activity for 90 seconds
after ”Closed Loop” has 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, Diagnostic Trouble Code P1134
will be set, indicating that the oxygen sensor is not
responding as expected to changes in exhaust oxygen
content. DTC P1134 is a type B code.

Conditions for Setting the DTC

f

No related Diagnostic Trouble Codes.

f

Engine coolant temperature (ECT) is above 60

°

C

(140

°

F).

f

Engine is operating in ”Closed Loop”.

f

The engine has been running at least two minutes.

f

Calculated air flow between 17 and 32 grams/sec.

f

Canister purge duty cycle is greater than 2%.

f

Engine speed is between 1500 RPM and 3500 RPM.

f

Above conditions are present for a 1–second
monitoring period.

f

90 seconds after ”Closed Loop” has been enabled,
Bank 1 HO2S 1 transition ratio between lean–to–rich
and rich–to–lean is less than 0.4 or greater than 3.8.

Action Taken When the DTC Sets

f

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

f

”Open Loop” fuel control will be in effect.

f

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

Conditions for Clearing the MIL/DTC

f

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.

f

A history Diagnostic Trouble Code P1134 will clear
after 40 consecutive warm–up cycles have occurred
without a fault.

f

Diagnostic Trouble Code P1134 can be cleared by
using the Scan Tool’s ”Clear Info” function.

Diagnostic Aids

A malfunction in the HO2S heater ignition feed or ground
circuit may cause a Diagnostic Trouble Code P1133 to
set. Check HO2S heater circuitry for intermittent faults or
poor connections. If connections and wiring are OK and

6E1–324

RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

Diagnostic Trouble Code P1134 continues to set, replace
the Bank 1 HO2S 1.
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:

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 P1134 – O2 Sensor Transition Time Ratio (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

IMPORTANT: If any DTCs are set 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 ”Conditions for Setting the Diagnostic
Trouble Code” criteria included in Diagnostic
Support.

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

info for Diagnostic Trouble Code P1134 until the
Diagnostic Trouble Code P1134 test runs.

4. Note the test result.

Does the Tech 2 indicate DTC P1134 failed this
ignition?

—

Go to Step 3

Refer to

Diagnostic

Aids

3

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

Exhaust System). After the ”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?

—

Verify repair

Go to Step 4

4

Visually/physically inspect the following items:

f

Ensure that the Bank 1 HO2S 1 is securely
installed.

f

Check for corrosion on the terminals.

f

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

f

Check for damaged wiring; shorts to ground,
shorts to battery positive, and open circuits.

Was a problem found in any of the above areas?

—

Go to Step 7

Go to Step 5

5

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

Go to Step 6

Go to Step 8

6E1–325

RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DTC P1134 – O2 Sensor Transition Time Ratio (Bank 1 Sensor 1)

(Cont'd)

Step

No

Yes

Value(s)

Action

6

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

10

Go to Step

11

7

Repair condition as necessary.

Is the action complete?

—

Verify repair

—

8

Check for faulty PCM connections or terminal damage.

Is the action complete?

—

Verify repair

Go to Step 9

9

Repair open, short or grounded signal circuit.

Is the action complete?

—

Verify repair

Go to Step 6

10

Remove the Bank 1 H02S 1 and examine it for signs of:

f

Fuel contamination;

f

Improper RTV sealant (white powdery coating on
sensor);

f

Engine oil/coolant consumption.

Were signs of contamination observed?

—

Go to Step

13

Go to Step

12

11

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 repair complete?

—

Verify repair

—

12

Replace the Bank 1 H02S 1.

Is the action complete?

—

Verify repair

—

6E1–326

RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DIAGNOSTIC TROUBLE CODE (DTC) P1171 FUEL SYSTEM LEAN DURING

ACCELERATION

D06RX048

Circuit Description

The powertrain control module (PCM) internal circuitry
can identify if the vehicle fuel system is capable of
supplying adequate amounts of fuel during heavy
acceleration (power enrichment). The PCM monitors the
voltage of the oxygen sensor during power enrichment.
When a power enrichment mode of operation is
requested during ”Closed Loop” operation (by heavy
acceleration), the PCM will provide more fuel to the
engine. Under these conditions the PCM should detect a
”rich” condition (high oxygen sensor voltage). If this ”rich”
exhaust is not detected at this time, a Diagnostic Trouble
Code P1171 will set. A plugged fuel filter or restricted fuel
line can prevent adequate amounts of fuel from being
supplied during power enrichment mode. DTC P1171 is a
type A code.

Conditions for Setting the DTC

f

No related Diagnostic Trouble Codes.

f

Engine is operating in ”Closed Loop”.

f

Engine coolant temperature is above 60

°

C (140

°

F).

f

While in ”power enrichment” mode the oxygen sensor
voltage remains below 400 mV for 3 seconds.

Action Taken When the DTC Sets

f

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

f

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

Conditions for Clearing the MIL/DTC

f

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.

f

A history Diagnostic Trouble Code P1171 will clear
after 40 consecutive warm–up cycles have occurred
without a fault.

f

Diagnostic Trouble Code P1171 can be cleared by
using the Scan Tool’s ”Clear Info” function.

Diagnostic Aids

f

A restricted fuel filter or fuel line can supply adequate
amounts of fuel at idle, but may not be able to supply
enough fuel during heavy acceleration.

f

Water or alcohol in the fuel may cause low HO2S
voltage during acceleration.

f

Check for faulty or plugged fuel injector(s).

f

Check for low fuel.