Toyota Sienna Service Manual: Check and replace ecu
• When no measuring condition is specified, perform the inspection with the engine stopped and the ignition switch on.
• Check that the connectors are fully seated. Check for loose, corroded or broken wires.
(a) First, check the ECU ground circuit. If it is faulty, repair it. If it is normal, the ECU could be faulty.
Temporarily replace the ECU with a normally functioning one and check if the symptoms occur. If the trouble symptoms disappear, replace the original ECU.
(1) Measure the resistance between the ECU ground terminal and body ground.
Standard resistance: Below 1 Ω
(2) Disconnect the ECU connector. Check the ground terminal on the ECU side and wire harness side for bending, corrosion or foreign matter. Lastly, check the contact pressure of the female terminals.
Check for short circuit
(a) If the wire harness is ground shorted (Fig. 5), locate the section by
conducting a resistance check with the body ground (below).
(b) Check the resistance with the body ground.
...
Other materials:
Inspection
1. INSPECT BRAKE CYLINDER AND PISTON
(a) Check the brake cylinder bore and rear disc brake
piston for rust or scoring.
2. INSPECT PAD LINING THICKNESS
(a) Using a ruler, measure the pad lining thickness.
Standard thickness:
11.0mm (0.433 in.)
Minimum thickness:
1.0 mm (0.039 in.)
3. INS ...
Mirror Motor Circuit
DESCRIPTION
A mirror control switch signal and memorized mirror positions are sent to the
outer mirror control ECU.
The outer mirror control ECU drives the selected mirror UP, DOWN, LEFT and RIGHT
in response to the
inputs.
HINT:
The power mirror control system is part of the large-scale ...
VSC Warning Light does not Come ON
DESCRIPTION
The skid control ECU is connected to the combination meter via CAN and
multiplex communications.
If the skid control ECU stores DTCs to shut down TRAC and VSC operation, the VSC
warning light comes
on in the combination meter.
WIRING DIAGRAM
Refer to VSC Warning Light Remains ...
