Toyota Celica 2005 Repair Manual page 322

DTC P0133
CIRCUIT DESCRIPTION
Refer to DTC P0130 on page DI−65.
DTC No.
After engine has been warmed up, response time that heated
oxygen sensor's output voltage changing between RICH and
LEAN is 0.6 second or more during idling.
(2 trip detection logic)
P0133
Response time of heated oxygen sensor's output voltage in
one RICH−LEAN cycle is 6 seconds or more during idling.
(2 trip detection logic)
HINT:
Sensor 1 is the sensor closer to the engine assembly.
MONITOR DESCRIPTION
Slow slope condition
0.45
0.35
The ECM uses the heated oxygen sensor information to regulate the air−fuel ratio close to a stoichiometric
ratio. This maximizes the catalytic converter's ability to purify the exhaust gas. The sensor detects oxygen
level in the exhaust gas and sends this signal to the ECM.
The inner surface of the sensor element is exposed to outside air. The outer surface of the sensor element
is exposed to exhaust gas. The sensor element is made of platinum coated zirconia and includes an inte-
grated heating element. The heated oxygen sensor has the characteristic whereby its output voltage
changes suddenly in the vicinity of the stoichiometric air−fuel ratio. The heated oxygen sensor generates
waveforms of a voltage between 0 V and 1 V in response to the oxygen concentration in exhaust gas. When
the output voltage of the heated oxygen sensor is 0.55 V or more, the ECM judges that the air−fuel ratio is
RICH. When it is 0.4 V or less, the ECM judges that the air−fuel ratio is LEAN.
The ECM monitors the response feature of the heated oxygen sensor. If the response time of the heated
oxygen sensor output status change from RICH to LEAN or vice versa becomes longer, the ECM interprets
this as a malfunction in the heated oxygen sensor and sets a DTC.
2005 CELICA (RM1131U)
DIAGNOSTICS
Oxygen Sensor Circuit Slow Response
(Bank 1 Sensor 1)
DTC Detecting Condition
Lean to Rich time
Rich
Lean to Rich / Rich to Lean time definition
− ENGINE (1ZZ−FE)
S Open or short in heated oxygen sensor circuit
S Heated oxygen sensor
S EFI relay
S Air induction system
S Fuel pressure
S Injector
S ECM
Rich to Lean time
Lean
321
Trouble Area
Time
DI−123
DIC6P−02
A20599