Toyota Sienna Service Manual: Back-up Power Source Circuit
DESCRIPTION
This is the back-up power source for the A/C amplifier. Power is supplied even when the ignition switch is off and is used for diagnostic trouble code memory, etc.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 INSPECT FUSE (ECU-B)
(a) Remove the ECU-B fuse from the engine room junction 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
ACC Power Source Circuit
DESCRIPTION
This circuit supplies power to the A/C amplifier and the illumination for the
clock.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 INSPECT FUSE (ECU ACC)
(a) Remove the ECU ACC fuse fr ...
Other materials:
Inspection
1. INSPECT OIL PUMP RELIEF VALVE
(a) Coat the relief valve with engine oil and check that it
falls smoothly into the valve hole under its own
weight.
If the valve does not fall smoothly, replace the relief
valve. If necessary, replace the oil pump assembly.
2. INSPECT OIL PUMP ROTOR SET
...
Write vin
(a) The VIN writing process is shown in the flowchart
below. This process allows the VIN to be input into
the ECM. If the ECM is changed, or the ECM VIN
and Vehicle VIN do not match, the VIN can be
registered, or overwritten in the ECM by following
this procedure.
(b) Write VIN using the int ...
MIL Circuit
DESCRIPTION
The MIL (Malfunction Indicator Lamp) is used to indicate vehicle malfunctions
detected by the ECM.
When the ignition switch is turned to the ON position, power is supplied to the
MIL circuit, and the ECM
provides the circuit ground which illuminates the MIL.
The MIL operation ...
