Toyota 1 MZ–FE Manual page 481

DTC P0135 P0141 P0155 Heated Oxygen Sensor Heater
Circuit Malfunction
(Bank 1 Sensor 1 – Bank 1 Sensor 2 – Bank 2 Sensor 1)
CIRCUIT DESCRIPTION
Refer to "Insufficient coolant temp. for closed loop fuel control" on page EG2–473.
Diagnostic Trouble Code Detecting Condition
DTC No.
When the heater operates, heater current exceeds 2 A
or voltage drop for the heater circuit exceeds 5 V.
P0135 (2 trip detection logic)
P0141
Heater current of 0.25 A or less when the heater
P0155
operates.
(2 trip detection logic)
H I NT: Bank 1 refers to the bank that includes cylinder No.1.
Bank 2 refers to the bank that does not include cylinder No.1.
Sensor 1 refers to the sensor closer to the engine body.
Sensor 2 refers to the sensor farther away from the engine body.
1MZ–FE ENGINE – CIRCUIT INSPECTION
Open or short in heater circuit of heated oxygen
sensor.
Heated oxygen sensor heater
ECM
Trouble Area
EG2–481