Toyota RM787U, Service And Repair Manual

Page: 617 / 1976

- DIAGNOSTICS ENGINE
DI-79
233
Author: Date:
2001 SIENNA (RM787U)
DTC No. DTC Detecting Condition Trouble Area
P0441
Pressure in charcoal canister and fuel tank does not drop dur-
ing purge control (2 trip detection logic)
Vacuum hose cracks, holed blocked, damaged or discon-
nected ((1), (2), (3), (4), (5), (6), (7), (8), (9), (10) and (11) in
Fig. 1)
F l k i l i ll d
When VSV for pressure switching valve is ON, ECM judges
that there is no continuity between vapor pressure sensor, fuel
tank and charcoal canister (2 trip detection logic)
Fuel tank cap incorrectly installed
Fuel tank cap cracked or damaged
Open or short in vapor pressure sensor circuit
Vapor pressure sensor
Open or short in VSV circuit for EVAP
P0446
When VSV for pressure switching valve is turned OFF, pres-
sure in fuel tank is maintained at atmospheric pressure (2 trip
detection logic)
O en or short in VSV circuit for EVAP
VSV for EVAP
Open or short in VSV circuit for CCV
VSV for CCV
Open or short in VSV circuit for pressure switching valve
VSV for pressure switching valve
When VSV for CCV is ON, pressure in charcoal canister and
fuel tank is maintained at atmospheric pressure (2 trip detec-
tion logic)
VSV for pressure switching valve
Fuel tank cracked, holed or damaged
Charcoal canister cracked, holed or damaged
Fuel tank over fill check valve cracked damaged
ECM
WIRING DIAGRAM
Refer to DTC P0440 on page DI-72 .
INSPECTION PROCEDURE
HINT:
If DTC P0441, P0446, P0450 or P0451 is output after DTC P0440 first troubleshoot DTC P0441,
P0446, P0450 or P0451. If no malfunction is detected, troubleshoot DTC P0440 next.
Read freeze frame data using TOYOTA hand-held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the malfunction is detected. When troubleshooting, it is useful for
determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel
ratio was lean or rich, etc. at the time of the malfunction.
When the ENGINE RUN TIME in the freeze frame data is less than 200 seconds, carefully check the
vapor pressure sensor.
TOYOTA hand-held tester:
1 Check whether hose close to fuel tank have been modified, and check whether
there are signs of any accident near fuel tank or charcoal canister (See page
DI-72 ).
NG Repair or replace.
OK
2 Check that fuel tank cap is TOYOTA genuine parts (See page DI-72 ).
NG Replace to TOYOTA genuine parts.