DTC P0138, P0158 HO2S2
EC-285
[VQ35DE]
C
D
E
F
G
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K
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A
EC
DTC P0138, P0158 HO2S2
PFP:226A0
Component Description
NBS004XA
The heated oxygen sensor 2, after three way catalyst 1, monitors the
oxygen level in the exhaust gas on each bank.
Even if switching characteristics of the air fuel ratio (A/F) sensor 1
are shifted, the air-fuel ratio is controlled to stoichiometric, by the sig-
nal 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.
CONSULT-II Reference Value in Data Monitor Mode
NBS004XB
Specification data are reference values.
On Board Diagnosis Logic
NBS004XC
The heated oxygen sensor 2 has a much longer switching time between rich and lean than the air fuel ratio (A/
F) sensor 1. The oxygen storage capacity of the three way catalyst 1 causes the longer switching time.
MALFUNCTION A
To judge the malfunctions of heated oxygen sensor 2, ECM monitors
whether the voltage is unusually high during the various driving con-
dition such as fuel-cut.
MALFUNCTION B
To judge the malfunctions of heated oxygen sensor 2, ECM monitors
whether the minimum voltage of sensor is sufficiently low during the
various driving condition such as fuel-cut.
SEF327R
MONITOR ITEM
CONDITION
SPECIFICATION
HO2S2 (B1)
HO2S2 (B2)
●
Revving engine from idle to 3,000 rpm quickly after the following conditions
are met
–
Engine: After warming up
–
Keeping engine speed between 3,500 and 4,000 rpm for 1 minute and at idle
for 1 minute under no load
0 - 0.3V
←→
Approx. 0.6 -
1.0V
HO2S2 MNTR (B1)
HO2S2 MNTR (B2)
LEAN
←→
RICH
PBIB1848E
PBIB2376E