Toyota Celica 2005 Repair Manual page 339

DI−140
DTC P0136
DTC P0138
CIRCUIT DESCRIPTION
Refer to DTC P0130 on page DI−112.
DTC No.
Voltage output of heated oxygen sensor remains at 0.4 V or
P0136 more or 0.5 V or less after engine is warmed up (2 trip detec-
tion logic)
One 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
MONITOR DESCRIPTION
The ECM monitors the rear heated oxygen sensor in the following 3 items:
(1) If the rear heated oxygen sensor voltage changes between RICH and LEAN while the vehicle
is running (repeating acceleration and deceleration), the ECM interprets this as a malfunction
and illuminates the MIL, and then sets a DTC.
(2) If the rear heated oxygen sensor voltage does not remain less than 0.05 V for a long period of
time while the vehicle is running, the ECM interprets this as a malfunction and illuminates the MIL,
and then sets a DTC.
(3) If the sensor's voltage drops below 0.2 V (extremely LEAN status) immediately when the vehicle
decelerates and the fuel cut is working. If not, the ECM interprets this as a sensor's response
feature deterioration and illuminates the MIL, and then sets DTC.
MONITOR STRATEGY
Related DTCs
Required sensors/ components (Main)
Required sensors/ components (Related)
Frequency of operation
Duration
MIL operation
Sequence of operation
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
P0136: Rear Heated Oxygen (HO2) sensor output voltage
P0138: Rear Heated Oxygen (HO2) sensor output voltage
Rear HO2 sensor
Mass air flow meter, vehicle speed sensor and engine coolant temperature sensor
Continuous: P0138 output voltage
Once per driving cycle: Others
Within 6 minutes: P0136
Within 6 seconds: P0138
Immediate: P0138 output voltage
2 driving cycles: Others
None
− ENGINE (1ZZ−FE)
S Open or short in heated oxygen sensor circuit
S Heated oxygen sensor
S Heated oxygen sensor heater
S EFI relay
S HO2 sensor (sensor 2)
S Short in HO2 sensor (sensor 2) circuit
338
Trouble Area
DID54−01