Toyota Celica 2005 Repair Manual page 559

DI−360
DTC P0031
DTC P0032
DTC P0037
DTC P0038
CIRCUIT DESCRIPTION
Refer to DTC P0130 on page DI−411.
HINT:
The ECM provides a pulse width modulated control circuit to adjust current through the heater. The heated
oxygen sensor heater circuit uses a relay on the B+ side of the circuit.
Reference (Bank 1 Sensor 1 System Drawing):
EFI Fuse
From
Battery
From
Terminal 6 of
Ignition Switch
DTC No.
P0031 Heater current is 0.25 A or less when heater operates with B+
P0037 greater than 11.5 V (1 trip detection logic)
P0032 Heater current exceeds 3.5 A when heater operates
P0038 (1 trip detection logic)
HINT:
Sensor 1 is to the sensor closer to the engine body.
S
Sensor 2 is to the sensor farther away from the engine body.
S
2005 CELICA (RM1131U)
DIAGNOSTICS
Oxygen Sensor Heater Control Circuit Low
(Bank 1 Sensor 1)
Oxygen Sensor Heater Control Circuit High
(Bank 1 Sensor 1)
Oxygen Sensor Heater Control Circuit Low
(Bank 1 Sensor 2)
Oxygen Sensor Heater Control Circuit High
(Bank 1 Sensor 2)
EFI Relay
Heated Oxygen Sensor
Ground Ground
DTC Detection Condition
− ENGINE (2ZZ−GE)
Heater
Sensor
S Open or short in heater circuit of heated oxygen sensor
S Heated oxygen sensor heater
S EFI relay
S ECM
558
ECM
HT1A
OX1A
Duty
Control
Trouble Area
DIC77−02
A21253