Lexus ES300 (2002 year). Manual - part 362
05-68
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DIAGNOSTICS
SFI SYSTEM (1MZ-FE)
221
2002 LEXUS ES300 REPAIR MANUAL (RM911U)
7
CHECK FUEL PRESSURE (See page
NG
GO TO FUEL SYSTEM
OK
8
CHECK EXHAUST GAS LEAK
NG
REPAIR OR REPLACE EXHAUST GAS
LEAKAGE POINT
OK
9
READ VALUE OF OBD II SCAN TOOL OR HAND-HELD TESTER(AIR FUEL RATIO
SENSOR)
(a)
Connect the OBD II scan tool or hand-held tester to the DLC3.
(b)
Warm up the A/F sensor with the engine speed at 2,500 rpm for approx. 90 sec.
(c)
Read the voltage value of the A/F sensor on the screen of OBD II scan tool or hand-held tester when
you perform all the following conditions.
HINT:
The voltage of the AFR+ or AFL+ terminal of the ECM is 3.3 fixed the AFR- or AFL- terminal is 3.0 V fixed.
Therefore, it is impossible to check the A/F sensor output voltage at the terminals (AFR+, AFL+/AFR-, AFL-)
of the ECM.
Air fuel ration sensor output voltage:
Condition
A/F Sensor Voltage value
Engine idling
Not remains at 3 30 V (0 660 V*)
Engine racing
Not remains at 3.30 V (0.660 V*)
Not remains at 3 8 V (0 76 V*) or more
Driving at engine speed 1,500 rpm or more and vehicle
speed 40 km/h (25 mph) or more, and operate throttle valve
open and close
Not remains at 3.8 V (0.76 V*) or more
Not remains at 2.8 V (0.56 V*) or less
*: When you use OBD II scan tool (excluding hand-held tester)
HINT:
During fuel enrichment, there is a case that the output voltage of the A/F sensor is below 2.8 V (0.56
V*), it is normal.
During fuel cut, there is a case that the output voltage of the A/F sensor is above 3.8 V (0.76 V*), it
is normal.
If the output voltage of the A/F sensor remains at 3.30 V (0.660 V*) even after performing all the above
conditions, the A/F sensor circuit may be open.
If the output voltage of the A/F sensor remains at 3.8 V (0.76 V*) or more, or 2.8 V (0.56 V*) or less
even after performing all the above conditions, the A/F sensor circuit may be short.
*: When you use the OBD II scan tool (excluding hand-held tester).
OK
NG