EC-906
< COMPONENT DIAGNOSIS >
[MR18DE]
P1146 HO2S2
P1146 HO2S2
Description
INFOID:0000000001161880
The heated oxygen sensor 2, after three way catalyst (manifold),
monitors the oxygen level in the exhaust gas on each bank.
Even if switching characteristics of the heated oxygen sensor 1 are
shifted, the air-fuel ratio is controlled to stoichiometric, by the signal
from the heated oxygen sensor 2.
This sensor is made of ceramic zirconia. The zirconia generates volt-
age from approximately 1V in richer conditions to 0V in leaner condi-
tions.
Under normal conditions the heated oxygen sensor 2 is not used for
engine control operation.
DTC Logic
INFOID:0000000001161881
DTC DETECTION LOGIC
The heated oxygen sensor 2 has a much longer switching time
between rich and lean than the heated oxygen sensor 1. The oxygen
storage capacity of the three way catalyst (manifold) causes the
longer switching time. To judge the malfunctions of heated oxygen
sensor 2, ECM monitors whether the minimum voltage of the sensor
is sufficiently low during the various driving condition such as fuel-
cut.
DTC CONFIRMATION PROCEDURE
1.
INSPECTION START
Do you have CONSULT-III?
Do you have CONSULT-III?
YES
>> GO TO 2.
NO
>> GO TO 11.
2.
PRECONDITIONING
“COMPLETED” will appear on CONSULT-III screen when all tests “COND1”, “COND2” and “COND3” are
completed.
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
• For the best results, perform
″
DTC WORK SUPPORT
″
at a temperature of 0 to 30
°
C (32 to 86
°
F).
• Never stop engine during this procedure. If the engine is stopped, retry this procedure from step 2 in
Procedure for COND1.
CAUTION:
Always drive at safe speed.
SEF327R
PBIB0554E
DTC No.
Trouble diagnosis name
DTC detecting condition
Possible cause
P1146
Heated oxygen sensor 2
minimum voltage moni-
toring
The minimum voltage from the sensor is not
reached to the specified voltage.
• Harness or connectors
(The sensor circuit is open or shorted)
• Heated oxygen sensor 2
• Fuel pressure
• Fuel injector
• Intake air leaks