The full-time 4WD SIENNA is equipped with the open center differential system.
If incorrect preparations or test procedures are used, the test will not only be unsuccessful, but may be dangerous as well.
Therefore, before beginning any such servicing or test, be sure to check the following items:
(a) Before Beginning Test
This vehicle does not have a center diff. lock mode or 4WD (Normal) Mode to allow only the front or rear wheel to be rotated.
The test method for this vehicle is different from that for vehicles equipped with the center diff. lock mode or 4WD (Normal) Mode, so make sure to use the correct test method.
Braking Force Test
(Vehicle Speed: Below 0.5 km/h or 0.3 mph) When performing low-speed type brake tester measurements, observe the following instructions.
(1) Position the wheels to be tested (front or rear) on the tester.
(2) Shift the transaxle shift lever to "N" position.
(3) Idle the engine, operate the brake booster and perform the test.
(c) Speedometer Test or Other Tests
(Using Speedometer Tester or Chassis Dynamometer)
When performing test at high speed or high load, use the methods shown below.
*: This is to avoid damaging the center differential.
(d) On-Vehicle Wheel Balancing
On-Vehicle Wheel Balancing
When doing on-vehicle wheel balancing on a fulltime 4WD vehicle, to prevent the wheels from rotating at different speeds in different directions from each other (which could damage the center differential), always be sure to observe the following precautions:
(1) All 4 wheels should be jacked up, clearing the ground completely.
(2) The parking brake lever should be fully released.
(3) None of the brakes should be allowed to drag.
(4) The wheels should be driven on the wheel balancer with the engine running.
HINT:
When doing this, be careful of the other wheels, which will rotate at the same time.
(5) Avoid sudden acceleration, deceleration and braking.
(6) Carry out wheel balancing with the transaxle in D position.
Removal
1. DISCONNECT CABLE FROM NEGATIVE BATTERY
TERMINAL
2. REMOVE AIR FUEL RATIO SENSOR (for Bank 2
Sensor 1)
(a) Disconnect the sensor connector.
(b) Using SST, remove the sensor from the exhaust
manifold.
SST 09224-00010
3. REMOVE FRONT EXHAUST PIPE ASSEMBLY
(a) Disconnect the heat ...
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
functioning properly. If any
malfunction is detected, the ECM sets the appropriate DTC and illumina ...
Door control switch
INSPECTION
1. INSPECT DOOR CONTROL SWITCH ASSEMBLY
Measure the resistance according to the value(s) in
the table below.
Standard resistance
HINT:
If the result is not as specified, replace the switch. ...