Toyota RM787U, Руководство по обслуживанию и ремонту

Страница: 593 / 1976

- DIAGNOSTICS ENGINE
DI-55
209
Author: Date:
2001 SIENNA (RM787U)
7 Check the output voltage A/F sensors (bank1, 2 sensor1).
PREPARATION:
(a)
Connect the OBDII scan tool or TOYOTA hand-held tester to the DLC3.
(b) Warm up the A/F sensors (bank1, 2 sensor1) with the engine at 2,500 rpm for approx. 90 sec.
CHECK:
Read voltage value of A/F sensors (bank1, 2 sensor1) on the screen of OBDII scan tool or TOYOTA hand-
held tester when you perform all the following conditions.
HINT:
The voltage of AFR
, AFL terminal of ECM is 3.3 fixed AFR , AFL terminal is 3.0 V fixed. Therefore,
it is impossible to check the A/F sensors (bank1, 2 sensor1) output voltage at the terminals (AFR , AFL /
AFR , AFL ) of ECM.
OK:
Condition A/F Sensor Voltage value
Engine idling
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 (25mph) 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 the OBDII scan tool (excluding TOYOTA hand-held tester)
HINT:
During fuel enrichment, there is a case that the output voltage of A/F sensors (bank1, 2 sensor1) is
below 2.8 V (*0.56 V), it is normal.
During fuel cut, there is case that the output voltage of A/F sensors (bank1, 2 sensor1) is above 3.8
V (*0.76 V), it is normal.
If output voltage of A/F sensors (bank1, 2 sensor1) remains at 3.30 V (*0.660 V) even after performing
all the above conditions, A/F sensors (bank1, 2 sensor1) circuit may be open.
If output voltage of A/F sensors (bank1, 2 sensor1) 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, A/F sensors (bank1, 2 sensor1) circuit may
be short.
*: When you use the OBDII scan tool (excluding TOYOTA hand-held tester).
OK Go to step 9.
NG
8 Check for open and short in harness and connector between ECM and A/F sen-
sors (bank1, 2 sensor1) (See page
IN-31 ).
NG Repair or replace harness or connector.
OK