Toyota Celica 2005 Repair Manual page 638

DTC P0136
DTC P0138
CIRCUIT DESCRIPTION
Refer to DTC P0130 on page DI−411.
DTC No.
Either of the following conditions is met:
S HO2 sensor (sensor 2) voltage remains LEAN (below 0.4 V)
or RICH (above 0.5 V) while the vehicle is repeating accelera-
P0136
tion and deceleration for 4 to 8 minutes
S HO2 sensor (sensor 2) voltage remains extremely low for a
long time
Either of the following conditions is met:
S HO2 sensor (sensor 2) voltage does not drop below 0.2 V
P0138
immediately when fuel−cut starts
S HO2 sensor output voltage is 1.2 V or more for 10 seconds
MONITOR DESCRIPTION
The ECM monitors the HO2 sensor (sensor 2) as follows:
The HO2 sensor voltage does not remain RICH (above 0.5 V) or LEAN (below 0.4 V) while the vehicle
S
is accelerated and decelerated for 4 to 8 minutes. If the voltage remains either RICH or LEAN, the ECM
interprets this as a malfunction, illuminates the MIL and sets a DTC.
The HO2 sensor voltage does not remain less than 0.05 V for a long time while the vehicle is running.
S
If the voltage remains less than 0.05 V for a long time, the ECM interprets this as a malfunction, illumi-
nates the MIL and sets a DTC.
The sensor voltage drops below 0.2 V (extremely LEAN condition) immediately when the vehicle de-
S
celerates and fuel−cut operates. If the voltage does not drop below 0.2 V, the ECM determines that
the response feature of the sensor has deteriorated, illuminates the MIL and sets a DTC.
2005 CELICA (RM1131U)
DIAGNOSTICS
Oxygen Sensor Circuit Malfunction (Bank 1
Sensor 2)
Heated Oxygen Sensor Circuit High Voltage
(Bank 1 Sensor 2)
DTC Detection Condition
− ENGINE (2ZZ−GE)
S Open or short in HO2 sensor (sensor 2) circuit
S HO2 sensor (sensor 2)
S HO2 sensor heater (sensor 2)
S EFI relay
S HO2 sensor (sensor 2)
S Short in HO2 sensor (sensor 2) circuit
637
Trouble Area
DI−439
DID59−01