Toyota Sienna Service Manual: Engine Control System Malfunction
DTC C1201/51 Engine Control System Malfunction
DESCRIPTION
If trouble occurs the engine control system, the ECM transmits the abnormality to the skid control ECU.
The skid control ECU set this DTC and the skid control ECU prohibits TRAC and
VSC control. 
INSPECTION PROCEDURE
1 CHECK ENGINE CONTROL SYSTEM
(a) Check if the normal system code is recorded for engine control system.
Result 
REPLACE ECM
Open or Short Circuit in ABS Solenoid Relay Circuit
DESCRIPTION
The ABS solenoid relay is built in the brake actuator assembly. This relay
supplies power to each ABS
solenoid. If the initial check is OK, after the ignition switch is turned to t ...
ECM Communication Circuit Malfunction
DTC C1203/53 ECM Communication Circuit Malfunction
DESCRIPTION
The circuit is used to send TRAC and VSC control information from the skid
control ECU to the ECM, and
engine control information fr ...
Other materials:
Reassembly
1. INSTALL CENTER SUPPORT BEARING ASSEMBLY NO.1
(a) Set the center support bearing assembly No. 1
(front) to the intermediate shaft, as shown in the
illustration.
(b) Install a new washer to the intermediate shaft.
NOTICE:
Be sure to install the bearing in the correct
direction.
(c ...
Front Occupant Classification Sensor LH Circuit
Malfunction
DTC B1780 Front Occupant Classification Sensor LH Circuit
Malfunction
DESCRIPTION
The front occupant classification sensor LH circuit consists of the occupant
classification ECU and the
front occupant classification sensor LH.
DTC B1780 is recorded when a malfunction is detected in the fron ...
Washer fluid
If any washer does not work or the
warning message appears on the
multi-information display, the
washer tank may be empty. Add
washer fluid.
WARNINGWhen refilling washer fluid
Do not refill washer fluid when the engine is hot or running, as
washer fluid
contains alcohol and ...
