Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 1316

6E1–340

RODEO Y22SE 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:

D

Fuel contamination;

D

Improper RTV sealant (white powdery coating on
sensor);

D

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

—

6E1–341

RODEO Y22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DIAGNOSTIC TROUBLE CODE (DTC) 

P1171 FUEL SYSTEM LEAN DURING ACCELERATION

060R100032

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

D

No MAP, IAT, ECT, TPS, Fuel Trim, Injector, Misfire,
CKP, EGR, EVAP DTCs Set.

D

Engine is operating in ”Closed Loop”.

D

Engine coolant temperature is above 60

°

C (140

°

F).

D

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

D

The commanded Air Flow Ratio is less than 3 sec.

The above conditions are met for 40 failures in 40
samples.

Action Taken When the DTC Sets

D

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

D

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

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

D

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

Diagnostic Aids

D

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.

D

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

D

Check for faulty or plugged fuel injector(s).

D

Check for low fuel.

6E1–342

RODEO Y22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

Test Description

Number(s) below refer to the step number(s) on the
Diagnostic Chart:
4. When the engine is idling or at steady cruise, the

HO2S voltage should vary from between
approximately 100 mV to 900 mV. During ”power
enrichment” mode, more fuel is needed and the
HO2S voltage should rise above 447 mV. This step
checks to see if the HO2S is operating properly.

5. Wrap a shop towel around the fuel pressure

connector to absorb any small amount of fuel
leakage that may occur when installing the gauge.
Ignition ON, pump pressure should be 235–320
kPa.

7. Add Caution: Use correct pliers so damage to fuel

lines will not occur.

6E1–343

RODEO Y22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DTC P1171 – Fuel System Lean During Acceleration

 

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

Are any component–related Diagnostic Trouble Codes
set?

—

Go to

component

DTC charts

Go to Step  3 

3

1. Check the vehicle’s fuel tank for an adequate

amount of fuel.

2. Add fuel to the vehicle’s fuel tank if the tank is almost

empty.

Was fuel added to the vehicle’s fuel tank?

—

Go to Step  4 

Go to Step  5 

4

1. Using a Tech 2, observe HO2S 1 voltage while

running warm engine(75

°

C–95

°

C [167

°

F–203

°

F])

at 1200 RPM.

2. HO2S 1 voltage should vary within the specified

range.

Does the voltage toggle back and forth within the
specified range?

100– 900 mV

Go to

Diagnostic

Aids 

Go to Step  5 

5

1. Disconnect the fuel pump relay and crank the

engine to relieve the fuel pressure.

2. Install the fuel pressure gauge.
3. Start the engine and idle at normal operating

temperature.

4. Disconnect the vacuum line going to the fuel

pressure regulator.

With the engine running, is the fuel pressure within the
specified range?

284– 325 kPa

Go to OBD

System

Check 

Go to Step  6 

6

Check for restricted fuel lines or restricted in–line filter.

Was a problem found?

—

Verify repair

Go to Step  7 

7

1. Ignition OFF.
2. Ignition ON, engine OFF.
3. Using a Tech 2, enable the fuel pump to operate.
4. Using pliers, slowly close the return line (do not

exceed the first specified value).

Using the pliers, can the fuel pressure be manipulated
to exceed the second specified value?

414 kPa 325

kPa

Go to

Diagnostic

Aids 

Go to  Step 8 

8

Check for:

D

Faulty fuel pump

D

Restricted fuel pump strainer (sock)

D

Incorrect fuel pump

D

Incorrect fuel being used

D

Hot fuel

—

Verify repair

—