Toyota Sienna Service Manual: System Voltage
MONITOR DESCRIPTION
The battery supplies electricity to the ECM even when the ignition switch is off. This power allows the ECM to store data such as DTC history, freeze frame data and fuel trim values. If the battery voltage falls below a minimum level, these memories are cleared and the ECM determines that there is a malfunction in the power supply circuit. When the engine is next started, the ECM illuminates the MIL and sets the DTC.
HINT:
If DTC P0560 is set, the ECM does not store other DTCs.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air-fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.
1 CHECK FUSE (EFI NO. 1 FUSE)
(a) Remove the EFI No. 1 fuse from the engine room junction block.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance: Below 1 Ω
(c) Reinstall the EFI No. 1 fuse.
2 INSPECT ECM (BATT VOLTAGE)
(a) Measure the voltage according to the value(s) in the table below.
Standard voltage 
REPLACE ECM (See page ES-498)
3 CHECK HARNESS AND CONNECTOR (ECM - EFI NO. 1 FUSE)
(a) Check the harness and the connector between the EFI No. 1 fuse and ECM.
(1) Remove the EFI No. 1 fuse from the engine room junction block.
(2) Disconnect the E4 ECM connector.
(3) Measure the resistance according to the value(s) in the table below.
Standard resistance : 
(4) Reconnect the ECM connector.
(5) Reinstall the EFI No. 1 fuse.
4 CHECK HARNESS AND CONNECTOR (EFI NO. 1 FUSE - BATTERY)
(a) Check the harness and the connector between the EFI No. 1 fuse and battery.
(1) Remove the EFI No. 1 fuse from the engine room junction block.
(2) Disconnect the negative battery cable.
(3) Measure the resistance according to the value(s) in the table below.
Standard resistance: 
(4) Reconnect the negative battery cable.
(5) Reinstall the EFI No. 1 fuse
5 INSPECT BATTERY
(a) Check that the battery is not depleted.
CHECK AND REPLACE ENGINE ROOM RELAY BLOCK
Cold Start Ignition Timing Performance
DESCRIPTION
This monitor will run when the engine is started at -10 to 50°C (14 to 122°F)
of the engine coolant
temperature. The DTC will set after the engine idling for 13 seconds (2 trip
...
Internal Control Module Random Access Memory (RAM) Error
DESCRIPTION
The ECM continuously monitors its own internal memory status, internal
circuits, and output signals
transmitted to the throttle actuator. This self-check ensures that the ECM is
...
Other materials:
Front Occupant Classification Sensor RH Collision
Detection
DTC B1786 Front Occupant Classification Sensor RH Collision
Detection
DESCRIPTION
DTC B1786 is output when the occupant classification ECU receives a collision
detection signal sent by
the front occupant classification sensor RH if an accident occurs.
DTC B1786 is also output when the front ...
No. 1 Clearance Warning Buzzer Circuit
DESCRIPTION
The clearance warning ECU receives the ultrasonic sensor signal to sound the
front warning buzzer.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 INSPECT FRONT BUZZER
Remove the clearance warning ECU with front buzzer.
Apply the battery voltage to the terminals 1 and 2 o ...
Installing the second seats
Installing the second outside seats
Align the marking on the seat side cover to the marking on the
rail cover and align the marking on the seat front/back cover to
the rail.
Tip-up seat
Ottoman seat
Lower the seat and engage the latches.
If you locked the seat lat ...
