Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual — part 1433
6E2–183
RODEO 6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS
compensate for some decrease. However, if fuel
pressure is too low, a DTC P0137 may be set. Refer
to
Fuel System Diagnosis.
D
Lean injector(s) – Perform “Injector Balance Test”.
D
Vacuum leaks – Check for disconnected or damaged
vacuum hoses and for vacuum leaks at the intake
manifold, throttle body, EGR system, and PCV system.
D
Exhaust leaks – An exhaust leak may cause outside air
to be pulled into the exhaust gas stream past the
HO2S, causing the DTC P0137 to set. Check for
exhaust leaks near the Bank 1 HO2S 2 sensor.
D
MAF sensor – The system can go lean if the MAF
sensor signal indicates an engine airflow
measurement that is not correct. Disconnect the MAF
sensor to see if the lean condition is corrected. If so,
replace the MAF sensor.
D
Fuel contamination – Water, even in small amounts,
can be delivered to the fuel injectors. The water can
cause a lean exhaust to be indicated. Excessive
alcohol in the fuel can also cause this condition. Refer
to
Fuel System Diagnosis for procedure to check for
fuel contamination.
D
If none of the above conditions are present, replace the
affected HO2S.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
3. DTC P0137 failing during operation may indicate a
condition described in the “Diagnostic Aids” above.
If the DTC0137 test passes while the Failure
Records conditions are being duplicated, an
intermittent condition 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 P0137 –HO2S Circuit Low Voltage Bank 1 Sensor 2
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 vehicle within the parameters specified
under “Conditions for Setting the DTC” criteria
included in Diagnostic Support.
4. Using a Tech 2, monitor Bank 1 HO2S 2 voltage.
Does the Bank 1 HO2S voltage remain below the
specified value?
22 mV
Go to
Step 4
Go to
Step 3
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 P0137
until the DTC P0137 test runs.
4. Note the test result.
Does the Tech 2 indicate DTC P0137 failed this
ignition?
—
Go to
Step 4
Refer to
Diagnostic
Aids
4
1. Turn ignition “OFF”.
2. Disconnect the PCM.
3. Check the Bank 1 HO2S 2 high and low signal
circuits for a short to ground or a short to the heater
ground circuit.
Were Bank 1 HO2S 2 signal circuits shorted?
—
Go to
Step 5
Go to
Step 6
5
Repair the Bank 1 HO2S 2 signal circuit.
Is the action complete?
—
Verify repair
—
6
1. Ignition “OFF”.
2. Leave the PCM and HO2S 2 disconnected.
3. Check for continuity between the high and low
signal circuits.
Was there continuity between the high and low circuits?
—
Go to
Step 7
Go to
Step 8
6E2–184
RODEO 6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0137 –HO2S Circuit Low Voltage Bank 1 Sensor 2
(Cont'd)
Step
No
Yes
Value(s)
Action
7
Repair the short between the high and low circuits.
Is the action complete?
—
Verify repair
—
8
1. Ignition “OFF”.
2. Reconnect the PCM, leave HO2S 2 disconnected.
3. Ignition “ON”.
Does the Tech 2 indicate Bank 1 HO2S 2 voltage near
the specified value?
425-475 mV
Refer to
Diagnostic
Aids
Go to
Step 9
9
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
—
6E2–185
RODEO 6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P0138 HO2S Circuit High Voltage Bank 1 Sensor 2
060R200054
Circuit Description
The powertrain control module (PCM) supplies bias
voltage of about 450 mV between the heated oxygen
sensor (HO2S) signal high and signal 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 exhaust is
rich, down through about 10 mV when the 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 2 voltage
remains excessively high for an extended period of time,
DTC P0138 will be set.
Conditions for Setting the DTC
D
No related DTCs.
D
Engine is operating in “closed loop”.
D
“Closed loop” commanded air/fuel ratio is between
14.5 and 14.8.
D
Engine coolant temperature is above 60
°
C (140
°
F).
D
Throttle angle is between 3% and 19%.
D
Bank 1 HO2S 2 signal voltage remains above 952 mV
during normal “closed loop” operation for a total of 106
seconds over a 125-second period of time.
OR
D
Bank 1 HO2S 2 signal voltage remains above 500 mV
during deceleration fuel cut–off mode operation for up
to 3 seconds.
Action Taken 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.
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 P0138 will clear after 40 consecutive
warm-up cycles have occurred without a fault.
D
DTC P0138 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the PCM battery
feed.
Diagnostic Aids
Check for the following conditions:
D
Fuel pressure – An excessively rich fuel mixture can
cause a DTC P0138 to be set. Refer to
Fuel System
Diagnosis.
D
Rich injector(s) – Perform “Injector Balance Test”.
D
Leaking injector – Refer to
Fuel System Diagnosis.
6E2–186
RODEO 6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS
D
Evaporative emissions (EVAP) canister purge – Check
for fuel saturation. If full of fuel, check the canister
control and hoses. Refer to
Evaporative Emission
(EVAP) Control System.
D
MAF sensor –The system can go rich if the MAF
sensor signal indicates an engine airflow
measurement that is not correct. Disconnect the MAF
sensor to see if the rich condition is corrected. If so,
replace the MAF sensor.
D
Check for a leak in fuel pressure regulator diaphragm
by checking the vacuum line to the regulator for the
presence of fuel. There should be no fuel in the
vacuum line.
D
TP sensor – An intermittent TP sensor output will
cause the system to go rich, due to a false indication
of the engine accelerating.
D
Shorted Heated Oxygen Sensor (HO2S) – If the HO2S
is internally shorted the HO2S voltage displayed on the
Tech 2 will be over 1 volt. Try disconnecting the
affected HO2S with the key “ON”, engine “OFF”. If the
displayed HO2S voltage changes from over 1000 mV
to around 450 mV, replace the HO2S. Silicon
contamination of the HO2S can also cause a high
HO2S voltage to be indicated. This condition is
indicated by a powdery deposit on the portion of the
HO2S exposed to the exhaust stream. If
contamination is noticed, replace the affected HO2S.
D
Open HO2S Signal Circuit of Faulty HO2S – A poor
connection or open in the HO2S signal circuit can
cause the DTC to set during deceleration fuel mode.
An HO2S which is faulty and not allowing a full voltage
swing between the rich and lean thresholds can also
cause this condition. Operate the vehicle while
monitoring the HO2S voltage with a Tech 2. If the
HO2S voltage is limited within a range between
300 mV to 600 mV, check the HO2S signal and wiring
and associated terminal connections.
D
If none of the above conditions are present, replace the
affected HO2S.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
3. DTC P0138 being set during deceleration fuel mode
operation may indicate a condition described in the
“Diagnostic Aids” above. If the DTC P0138 test
passes while the Failure Records conditions are
being duplicated, an intermittent condition 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 P0138 – HO2S Circuit High Voltage Bank 1 Sensor 2
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 vehicle within the parameters specified
under “Conditions for Setting the DTC” criteria
included in Diagnostic Support.
4. Using a Tech 2, monitor Bank 1 HO2S 2 voltage.
Does the Bank 1 HO2S voltage remain above the
specified value?
952 mV
(500 mV in
deceleration
fuel cutoff
mode)
Go to
Step 4
Go to
Step 3
3
1. Ignition “ON”, review and record Tech 2 Failure
Records data.
2. Operate the vehicle within Failure Records
conditions as noted.
3. Using a Tech 2, monitor “DTC” info for DTC P0138
until the DTC P0138 test runs.
4. Note the test result.
Does the Tech 2 indicate DTC P0138 failed this
ignition?
—
Go to
Step 4
Refer to
Diagnostic
Aids
4
1. Ignition “OFF”.
2. Disconnect Bank 1 HO2S 1.
3. Ignition “ON”.
4. At the HO2S Bank 1 Sensor 2 connector (PCM
side), use a DVM to measure voltages at the high
and low signal terminals.
Are the voltages above the specified range?
3-4 V
Go to
Step 5
Go to
Step 6
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст