Toyota Sienna Service Manual: Refrigerant
On-vehicle inspection
1. INSPECT REFRIGERANT PRESSURE WITH MANIFOLD GAUGE SET
(a) This method uses a manifold gauge set to locate problem areas. Read the manifold gauge pressure when these conditions are established.
Test conditions:
- Temperature at the air inlet is 30 to 35°C (86 to 95°F).
- Engine is running at 1,500 rpm.
- All doors are fully open.
- Blower speed control switch is at HI.
- Temperature control switch is at MAX. COOL.
- A/C switch is ON.
(b) Gauge readings (Reference)
(1) Normally functioning refrigeration system
Gauge reading 
(2) The A/C system periodically changes between normal and improper function due to moisture in the refrigerant system.
(3) The A/C system does not function effectively due to insufficient cooling.
(4) The A/C system does not function effectively due to poor circulation of the refrigerant.
(5) The A/C system does not function intermittently because the refrigerant does not circulate.
(6) The A/C system does not function effectively due to overcharged refrigerant or insufficient cooling of the condenser.
(7) The A/C system does not function due to air in the refrigeration system.
| CAUTION: The low-pressure piping may be very hot and cause serious burns. |
(8) The A/C system does not function effectively due to an expansion valve malfunction.
(9) The A/C system does not function due to a defective compressor.
Gauge readings (Reference)
Terminals of ecu
1. A/C AMPLIFIER
HINT:
Check from the rear of the connector while it is
connected to the A/C amplifier.
(a) Waveform 1:
(b) Waveform 2: ...
Replacement
1. DISCHARGE REFRIGERANT FROM
REFRIGERATION SYSTEM
SST 07110-58060 (07117-58080, 07117-58090,
07117-78050, 07117-88060, 07117-88070,
07117-88080)
(a) Turn the A/C switch to ON.
(b) Operating t ...
Other materials:
AVC-LAN Circuit
DESCRIPTION
Each unit of the navigation system connected to the AVC-LAN (communication
bus) transfers the signal of
each switch by communication.
When a short to +B or short to ground occurs in this AVC-LAN, the navigation
system will not function
normally as the communication is discontin ...
Removal
1. RECOVER REFRIGERANT FROM REFRIGERATION
SYSTEM (See page AC-172)
2. REMOVE NO. 2 AIR CLEANER INLET (See page EM-
28)
3. REMOVE FRONT BUMPER ASSEMBLY (See page
ET-3)
4. DISCONNECT DISCHARGE HOSE SUB-ASSEMBLY
(a) Remove the bolt and disconnect the discharge hose
sub-assembly from the coo ...
Inspection
1. INSPECT BRAKE VACUUM CHECK VALVE ASSEMBLY
(a) Check the vacuum check valve.
(1) Slide the clip and disconnect the vacuum hose.
(2) Remove the vacuum check valve.
(3) Check that there is ventilation from the booster
to the engine, and no ventilation from the
engine to the booster.
...