6E–198
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
check EVAP control system components 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 rich condition is corrected. If so,
replace MAF sensor.
D
Check for leaking fuel pressure regulator diaphragm by
checking vacuum line to 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 cause a high HO2S
voltage to be indicated. This condition is indicated by
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
switch between the rich and lean thresholds can also
cause the condition. Operate the vehicle while
monitoring the HO2S voltage with a Tech 2. If the
HO2S is limited within a range between 300 mV to
600 mV, check the HO2S signal circuit 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 P0152 failing during deceleration fuel cutoff
mode operation may indicate a condition described
in the “Diagnostic Aids” above. If the DTC P0152
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 P0152 – HO2S Circuit High Voltage Bank 2 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. Engine is 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 2 HO2S 1 voltage.
Does the Bank 2 HO2S 1 voltage remain above the
specified value?
952 mV
(500 mV in
deceleration
fuel cut-off
mode)
Go to
Step 4
Go to
Step 3
3
1. Ignition “ON”.
2. Review and record Tech 2 Failure Records data.
3. Operate the vehicle within Failure Records
conditions as noted.
4. Using a Tech 2, monitor “DTC” info for DTC P0152
until the DTC P0152 test runs.
5. Note the test result.
Does the Tech 2 indicate DTC P0152 failed this
ignition?
—
Go to
Step 4
Refer to
Diagnostic
Aids
4
1. Ignition “OFF”.
2. Disconnect Bank 2 HO2S 1.
3. Ignition “ON”.
4. At HO2S Bank 2 Sensor 1 connector (PCM side)
use a DVM to measure voltages at the high and low
signal terminals.
Are the voltages in the specified range?
3-4 V
Go to
Step 5
Go to
Step 6