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:
Noise Occurs
INSPECTION PROCEDURE
1 NOISE CONDITION
Check in which direction the noise comes from (front left
or right, or rear left or right).
Check in which direction the noise comes from.
OK:
The location of the noise source can be
determined
2 CHECK SPEAKERS
Check the installatio ...
Problem symptoms table
HINT:
Before inspecting the suspected areas listed in the table
below, check the fuse and relay.
Before inspecting the suspected areas listed in the table
below, check for DTCs.
Methods used to verify the cause of the problem are listed
in order of probability in the ...
How to proceed with
troubleshooting
HINT:
Troubleshoot in accordance with the procedures on the
following pages.
1 VEHICLE BROUGHT TO WORKSHOP
2 DTC CHECK
Check for DTCs and make a note of the code that is
output (See page MP-14).
Delete the DTC.
Check if the DTC is output once again when the problem
symptom is simulat ...
