Toyota Celica 2005 Repair Manual page 311

DI−112
DTC P0130
CIRCUIT DESCRIPTION
The heated oxygen sensor is used to monitor oxygen concentration in the exhaust gas. For optimum catalyt-
ic converter operation, the air fuel mixture must be maintained near the ideal stoichiometric ratio. The heated
oxygen sensor output voltage changes suddenly in the vicinity of the stoichiometric ratio. The ECM adjusts
the fuel injection time so that the air−fuel ratio is nearly stoichiometric.
When the air−fuel ratio becomes LEAN, the oxygen concentration in the exhaust gas increases. And the
heated oxygen sensor informs the ECM of the LEAN condition (low voltage, i.e. less than 0.45 V).
When the air−fuel ratio is richer than the stoichiometric air−fuel ratio, the oxygen will be vanished from the
exhaust gas. And the heated oxygen sensor informs the ECM of the RICH condition (high voltage, i.e. more
than 0.45 V).
Element
Exhaust Gas
A
DTC No.
Output voltage of heated oxygen sensor remains at 0.4 V or
P0130 more, or 0.5 V or less, during idling after engine is warmed up
(2 trip detection logic)
HINT:
Sensor 1 is the sensor closest to the engine assembly.
S
The output voltage of the heated oxygen sensor and the short−term fuel trim value can be read using
S
the hand−held tester or the OBD ll scan tool.
2005 CELICA (RM1131U)
DIAGNOSTICS
Oxygen Sensor Circuit (Bank 1 Sensor 1)
Cover
A
A−A Section
DTC Detection Condition
− ENGINE (1ZZ−FE)
Heater
Solid Electrolyte
(Zirconia Element)
Platinum Electrode
Air
S Open or short in heated oxygen sensor (bank 1 sensor 1)
circuit
S Heated oxygen sensor (bank 1 sensor 1)
S Heated oxygen sensor heater (bank 1 sensor 1)
S EFI relay
S Air induction system
S Fuel pressure
S Injector
S ECM
310
Ideal Air−Fuel Mixture
Richer − Air Fuel Ratio − Leaner
Trouble Area
DIC6O−02
A21762