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:
No. 2 Speaker with box
COMPONENTS
ON-VEHICLE INSPECTION
1. INSPECT NO.2 SPEAKER WITH BOX
HINT:
Remove interior parts so that the No.2 speaker with box
can be seen.
Check the speaker installation.
OK:
The speaker is securely installed.
If the result is not as specified, reinstall the No.2
s ...
Engine
GENERAL MAINTENANCE
HINT:
Inspect these items when the engine is cold.
1. INSPECT DRIVE BELT
HINT:
(See page EM-6)
2. REPLACE SPARK PLUGS
HINT:
(See page IG-8)
3. INSPECT AIR FILTER
(a) Remove the air filter.
(b) Visually check that the air filter is not excessively
damaged or oily ...
Removal
1. DRAIN POWER STEERING FLUID
2. REMOVE FRONT WHEEL RH
3. REMOVE FRONT FENDER APRON SEAL RH (See
page EM-26)
4. REMOVE FAN AND GENERATOR V BELT (See page
EM-6)
5. DISCONNECT NO. 1 FLUID RESERVOIR TO PUMP HOSE
(a) Slide the clip and disconnect the No. 1 fluid
reservoir to pump hose from t ...
