Toyota Sienna Service Manual: Rear Air Conditioning Relay Circuit
DESCRIPTION
The RR A/C relay is switched on by signals from the A/C amplifier. It supplies power to the rear blower motor.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 INSPECT RELAY (RR A/C)
(a) Remove the RR A/C relay from the No. 3 relay block.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance 
2 CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER - BATTERY)
(a) Disconnect the connector from the A/C amplifier.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
Rear Air Conditioning Control Panel Circuit
DESCRIPTION
This is the rear A/C system control signal circuit as well as the power
supply circuit of the rear A/C control
assembly.
Pulse signals regarding rear A/C control panel switch operat ...
Rear Blower Motor Circuit
DESCRIPTION
Power to the rear blower motor is supplied from the battery via the RR A/C
relay.
The rear blower motor speed level varies between 0 and 31 based on the voltage
difference measured ...
Other materials:
On-vehicle inspection
1. INSPECT FRONT AIRBAG SENSOR (VEHICLE NOT
INVOLVED IN COLLISION)
Perform a diagnostic system check.
2. INSPECT FRONT AIRBAG SENSOR (VEHICLE
INVOLVED IN COLLISION AND AIRBAG HAS NOT
DEPLOYED)
Perform a diagnostic system check.
When the front bumper of the vehicle o ...
Air conditioning controls
Adjusting the temperature setting
Press “” on the “TEMP” button to
increase the temperature and “”
to decrease the temperature.
Adjusting the fan speed
Press “” on
to increase the fan speed and “”
to decrease
the fan speed.
Press the “OFF” button to turn the ...
Diagnosis system
1. DESCRIPTION
(a) When troubleshooting OBD II vehicles, the only
difference from the usual troubleshooting procedure
is to connect an OBD II scan tool complying with
SAE J1987 or a intelligent tester to the vehicle, and
read off various data output from the vehicle's ECM.
(b) OBD II reg ...
