The clock, radio, interior lights, unlocking from key fob, and speedometer aren't working

SOURCE: Toyota RAV 4 1.8 A - engine doesn't start after battery exchange

may sound like a dumb question but you didnt by chance hook up the battery or jumpstart the car with polarity reversed by accident at some point during this process? i would check all the underhood main fuses and interior fuses as well, what is the condition of the battery post clamps? if they are badly corroded be sure to clean them very well and wash them with a baking soda and water solution im thinking one of the cables or smaller wires that hook up at the battery is broken or possibly some freak accident happend and the computers need to be flashed at a dealer. either way i wish you luck please rate -jeff

SOURCE: Check engine and VSC lights on

I talked to you on the live chat, and I think that you may have missed the end of my typing...

What I went on to say is that more often than not, on the 02 4Runners, the Check and VSC lights in tandem look mainly after the emission system, and, since you stated no issues during the road test, I would guess that it is a fuel issue (too full/loose gas cap). But, if you can get the vehicle scanned, I will be very glad to provide you with more and better info if you provide me with the DTC codes. That would require your guy or an autozone hookup to a scan tool. I hope my clarification helps; and the graciouness of a FIxYa rating for this question would be greatly appreciated

SOURCE: central locking remote won't open car/car won't start

Sounds like a basic bad battery. Even though its not that old it can be bad....and probably under warranty. Immobilizer or starter will not cause that. Get the bat tested.
Only other thing is called a "parasitic draw". This is when something is drawing current from the battery when its supposed to be off. Usually this causes a totally dead battery, not a weak one like you have.

SOURCE: speedometer and odometer stops working all of a sudden

speed sensor

SOURCE: Radio, clock, cigarette lighters not working

all on the same circuit. radio has two power supplys, one when the key on, and one all the time. aftermarket decks draw alot more than factory and this circuit may not be able to handle the extra load. look in owners manual and look in engine and interior fuse panels. it may say memory,clock,ecm keep alive etc. if need be check them all one is failed. now as for the engine light, most obdII vehicles use this circuit to keep computer memory alive... it will set a code for voltage lost. if you know your not overloaded or have a short, then its safe to go up to next size fuse,2.5 or 5 amp heavier. but thats it. if keeps happening you have a short or you may have to run a dedicated feed circuit for the deck. good luck youll find it

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