Toyota Sienna Service Manual: Evaporative Emission System Switching Valve Control Circuit High
DTC SUMMARY
DESCRIPTION
The circuit description can be found in the EVAP (Evaporative Emission) System (See page ES-404).
INSPECTION PROCEDURE
Refer to the EVAP System (See page ES-404).
MONITOR DESCRIPTION
5 hours*1 after the ignition switch is turned off, the electric vacuum pump creates negative pressure (vacuum) in the EVAP (Evaporative Emission) system. The ECM monitors for leaks and actuator malfunctions based on the EVAP pressure.
HINT: *1: If the engine coolant temperature is not below 35°C (95°F) 5 hours after the ignition switch is turned off, the monitor check starts 2 hours later. If it is still not below 35°C (95°F) 7 hours after the ignition switch is turned off, the monitor check starts 2.5 hours later.
*2: If only a small amount of fuel is in the fuel tank, it takes longer for the EVAP pressure to stabilize.
The vent valve turns ON (closes) and the EVAP (Evaporative Emission) system pressure is then measured by the ECM, using the pressure sensor, to conduct an EVAP leak check. If the pressure does not increase when the vent valve is open, the ECM interprets this as the vent valve being stuck open. The ECM illuminates the MIL and sets the DTC.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
MONITOR RESULT
Refer to CHECKING MONITOR STATUS (See page ES-19).
Oxygen (A/F) Sensor Pumping Current Circuit
HINT:
Although the DTC titles say oxygen sensor, these DTCs relate to the
Air-Fuel Ratio (A/F) sensor.
Sensor 1 refers to the sensor mounted in front of the Three-Way
Catalytic Convert ...
ECM / PCM Internal Engine Off Timer Performance
DTC SUMMARY
DESCRIPTION
To ensure the accuracy of the EVAP (Evaporative Emission) monitor values, the
soak timer, which is built
into the ECM, measures 5 hours (+/- 15 minutes) from when the ...
Other materials:
Occupant Classification ECU Malfunction
DTC B1795 Occupant Classification ECU Malfunction
DESCRIPTION
DTC B1795 is recorded when a malfunction is detected in the occupant
classification ECU.
Troubleshoot DTC B1771 first when the DTCs B1771 and B1795 are output
simultaneously.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 CHECK DTC ...
Disassembly
1. REMOVE NO. 1ULTRASONIC SENSOR RETAINER
(w/ Clearance Sonar System) (See page PM-19)
2. REMOVE NO. 1 ULTRASONIC SENSOR (w/
Clearance Sonar System) (See page PM-19)
3. REMOVE REAR BUMPER ENERGY ABSORBER
4. REMOVE REAR BUMPER BAR PLATE
Remove the 4 clips and the rear bumper bar plate.
5. ...
Air Outlet Damper Position Sensor Circuit
DESCRIPTION
This sensor detects the position of the air outlet control servo motor and
sends the appropriate signals to
the A/C amplifier. The position sensor is built in the air outlet control servo
motor. The position sensor's
resistance changes as the air outlet control servo motor arm ...