0.02 In. Leak Pressure Measurement - Toyota 1NZ-FE User Manual

c. 0.02 in. Leak Pressure Measurement
1) The vent valve remains off, and the ECM introduces atmospheric pressure into the canister and
actuates the leak detection pump in order to create a negative pressure.
2) At this time, the pressure will not decrease beyond a 0.02 in. pressure due to the atmospheric pressure
that enters through a 0.02 in. diameter reference orifice measuring 0.5 mm (0.02 in.).
3) The ECM compares the logic value and this pressure, and stores it as a 0.02 in. leak pressure in its
memory.
4) If the measurement value is below the standard, the ECM will determine that the reference orifice
is clogged and store DTC (Diagnostic Trouble Code) P043E in its memory.
5) If the measurement value is above the standard, the ECM will determine that a high flow rate pressure
is passing through the reference orifice and store DTCs (Diagnostic Trouble Codes) P043F, P2401,
P2402, and P2422 in its memory.
Atmosphere
Purge VSV
(OFF)
ECM
ON (Open)
Purge VSV
OFF (Close)
Vent Valve
OFF (Vent)
Pump Motor
Atmospheric Pressure
System Pressure
0.02 in. Pressure
ENGINE - 1NZ-FE ENGINE
ON
ON
OFF
0.02 in. Pressure Measurement
Canister Pump Module
Vent Valve
(OFF)
M
Leak Detection
Pump & Pump
Motor
P
Canister Pressure
Sensor
Reference Orifice
EG-53
00REG26Y
D13N26