Toyota Celica 2005 Repair Manual page 643

DI−444
The following the A/F CONTROL procedure enables the technician to check the graph of the voltage outputs
of both the heated oxygen sensors.
To display the graph indication, enter "ACTIVE TEST / A/F CONTROL / USER DATA," then select "O2S B1S1
and O2S B1S2" by pressing "YES" and then "ENTER" button before pressing "F4" button.
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.
1 Are there any other codes (besides DTC P0136 or P0138) being output?
NO
2 Check output voltage of heated oxygen sensor.
PREPARATION:
(a) Connect the OBD II scan tool or the hand−held tester to the DLC3.
(b) After warming up the engine, run the engine at 2,500 rpm for 3 minutes.
CHECK:
Read the voltage output of the heated oxygen sensor when the engine speed is suddenly increased.
HINT:
Quickly run the engine to 4,000 rpm for 3 minutes by using the accelerator pedal.
OK:
Heated oxygen sensor output voltage: Fluctuates repeatedly between less than 0.4 V and more
than 0.5 V.
NG
3 Inspect heated oxygen sensor (heater resistance) (See page SF−75).
OK
2005 CELICA (RM1131U)
DIAGNOSTICS − ENGINE (2ZZ−GE)
YES Go to relevant DTC chart (See page DI−335).
OK Go to step 6.
NG Replace heated oxygen sensor.
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