Toyota Celica 2005 Repair Manual page 615

DI−416
NOTICE:
There is a delay of few seconds in the sensor 1 (front sensor) output, and there is approximately 20
seconds delay at maximum in the sensor 2 (rear sensor).
Output voltage of heated oxygen
sensor (sensor 1: front sensor)
Injection volume
+25 %
−12.5 %
Output voltage
Case 1
More than 0.5 V
Less than 0.4 V
Injection volume
+25 %
−12.5 %
Output voltage
Case 2
Almost
no reaction
Injection volume
+25 %
−12.5 %
Output voltage
Case 3
More than 0.5 V
Less than 0.4 V
Injection volume
+25 %
−12.5 %
Case 4
Output voltage
Almost
no reaction
The following of A/F CONTROL procedure enables the technician to check and graph the voltage outputs
of both the heated oxygen sensors.
For displaying the graph indication, enter "ACTIVE TEST / A/F CONTROL / USER DATA", then select "O2S
B1S1 and O2S B1S2" by pressing "YES" button and push "ENTER" button before pressing "F4" button.
NOTICE:
If the vehicle is short of fuel, the air−fuel ratio becomes LEAN and heated oxygen sensor DTCs will
be recorded, and the MIL then comes on.
HINT:
If different DTCs related to different systems that have terminal E2 as the ground terminal are output
S
simultaneously, terminal E2 may be open.
Read freeze frame data using the hand−held tester or the OBD II scan tool. Freeze frame data records
S
the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can
help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air−fuel
ratio was lean or rich, as well as other data from the time when a malfunction occurred.
A high heated oxygen sensor (sensor 1) voltage (0.5 V or more) could be caused by a rich air fuel mix-
S
ture. Check for conditions that would cause the engine to run rich.
A low heated oxygen sensor (sensor 1) voltage (0.4 V or less) could be caused by a lean air fuel mix-
S
ture. Check for conditions that would cause the engine to run lean.
2005 CELICA (RM1131U)
DIAGNOSTICS − ENGINE (2ZZ−GE)
Output voltage of heated oxygen
sensor (sensor 2: rear sensor)
Injection volume
+25 %
−12.5 %
Output voltage
More than 0.5 V
OK
Less than 0.4 V
Injection volume
+25 %
−12.5 %
Output voltage
More than 0.5 V
NG
Less than 0.4 V
Injection volume
+25 %
−12.5 %
Output voltage
Almost
OK
no reaction
Injection volume
+25 %
−12.5 %
Output voltage
Almost
NG
no reaction
614
Mainly suspected
trouble area
⎯
OK
Sensor 1: front sensor
(sensor 1, heater, sensor 1
circuit)
OK
Sensor 2: rear sensor
(sensor 2, heater, sensor 2
circuit)
NG
Extremely rich or lean actual
air−fuel ratio
(Injector, fuel pressure, gas
leakage in exhaust system,
NG
etc.)