Toyota 2GR-FE Manual page 519

Standard voltage
Condition
(1) and (2)
(3)
Normal Condition:
(3) Approximately 4,000 rpm
(2) Approximately 2,500 rpm
(1) Idling
Engine RPM
A/F Sensor
Voltage
"Condition (1), (2)"
Change at approximately 3.3 V
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
(d) Warm up the Air-Fuel Ratio (A/F) sensor at an engine
speed of 2,500 rpm for 90 seconds.
(e) On the tester, enter the following menus: DIAGNOSIS /
ENHANCED OBD II / SNAPSHOT / MANUAL
SNAPSHOT / USER DATA / AFS B1 S1 or AFS B2 S1
and ENGINE SPD.
(f) Check the A/F sensor voltage three times, when the
engine is in each of the following conditions:
(1) While idling (check for at least 30 seconds)
(2) At an engine speed of approximately 2,500 rpm
(3) Raise the engine speed to 4,000 rpm and then
A/F Sensor Voltage Variation
Changes at approximately 3.3 V
Increases to 3.8 V or more
HINT:
• For more information, see the diagrams below.
(1) Idling
Fuel-cut
"Condition (3)"
3.8 V or more
• If the output voltage of the A/F sensor remains at
approximately 3.3 V (see Malfunction Condition diagram)
under any conditions, including those above, the A/F
sensor may have an open circuit. (this will also happen if
the A/F sensor heater has an open circuit.)
• If the output voltage of the A/F sensor remains at either
approximately 3.8 V or more, or 2.8 V or less (see
Malfunction Condition diagram) under any conditions,
including those above, the A/F sensor may have a short
circuit.
(without any sudden changes in engine speed)
quickly release the accelerator pedal so that the
throttle valve is fully closed.
This occurs during engine deceleration
Malfunction Condition:
(3) Approximately 4,000 rpm
(2) Approximately 2,500 rpm
(1) Idling
Engine RPM
A/F Sensor
Voltage
When A/F sensor circuit is malfunctioning,
voltage output does not change
ES–363
Reference
Between 3.1 V and 3.5 V
(when fuel-cut performed)
(1) Idling
Fuel-cut
A107161E14
ES