Toyota Sienna Service Manual: Heater relay (for rear air conditioning system)
ON-VEHICLE INSPECTION
1. INSPECT REAR HEATER RELAY
(a) Remove the rear heater relay.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance 
If the resistance is not as specified, replace the rear heater relay.
Heater relay
ON-VEHICLE INSPECTION
1. INSPECT HEATER RELAY
(a) Remove the heater relay.
(b) Measure the resistance according to the value(s) in
the table below.
Standard resistance
If the resistance i ...
Air conditioning control assembly
COMPONENTS
...
Other materials:
Diagnostic trouble code chart
If a malfunction code is displayed during the DTC check,
check the circuit listed for that code in the chart below
(Proceed to the page given for that circuit).
MULTIPLEX COMMUNICATION SYSTEM
DTC Code
Detection Item
Trouble Area
B1200
MPX Body ECU Stop
...
Removal
1. PRECAUTION
CAUTION:
Be sure to read "PRECAUTION" thoroughly before servicing.
2. DISCONNECT CABLE FROM NEGATIVE BATTERY
TERMINAL
CAUTION:
Wait for 90 seconds after disconnecting the cable to
prevent the airbag working.
3. REMOVE FRONT SEAT ASSEMBLY (for Manual Seat)
4. REMOVE F ...
VC Output Circuit
DESCRIPTION
The ECM constantly uses 5 V from the battery voltages supplied to the +B (BATT)
terminal to operate the
microprocessor. The ECM also provides this power to the sensors through the VC
output circuit.
When the VC circuit is short-circuited, the microprocessor in the ECM and
sens ...
