Though this thread is old but I am posting thinking may be someone can help. I too have prado 2003 tz petrol 3.4, recently I gave cow bath to the vehicle and also disconnected and re-connected the read left light, from then onwards it is doing the same thing, that is, showing misleading meter readings for fuel guage, rpm meter, speedOmeter and temperature guage. Sometimes it gets normal but for short time.
Please help, if someone knows the solution, thanks.