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.
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Other materials:
Changing engine switch modes
Modes can be changed by pressing the engine switch with the brake
pedal released. (The mode changes each time the switch is pressed.)
Off*
Emergency flashers can be used.
ACCESSORY mode
Some electrical components such
as the audio system can be used.
The engine switch indicator tu ...
Installation
1. INSTALL TRANSFER ASSEMBLY
(a) Apply sealant 1281 to the transaxle assembly and
transfer assembly in continuous beaded from of 1.2
mm diameter as shown in the illustration.
NOTICE:
Wipe any grease off from the attaching
surfaces.
Install it within 10 minutes after applying the
se ...
Transmission Range Sensor Circuit Malfunction
(PRNDL Input)
DESCRIPTION
The park/neutral position switch detects the shift lever position and sends
signals to the ECM.
MONITOR DESCRIPTION
These DTCs indicate a problem with the park/neutral position switch and the
wire harness in the park/
neutral position switch circuit.
The park/neutral po ...