Auto transmisstion 4th gear issue

[asifhashmi]

Dear Experts,
i have a corona with 4AFE auto 4 forward transmission. i am facing a strange problem with its transmission which my local mechanic and even toyota motors @ industrial area, karachi cant explain and rectify.
the problem is that the car doesn't shift into the 4th gear unless it reached a specific temperate which is just above the c on the temp guage. earlier it had no such issue.... as a remedy my mechanic advised to flush the transmission fluid and poured zic transmission oil the red bottle... but the problem is still there.... and for the last couple of days i am feeling as if the car is dragging in each gear longer than it use to do... hope u understand what i mean... and i have to pump the paddle to shift the gear.....
plz advise what it cud be and what need to be done to fix it

[Xulfiqar]

This behavior is completely normal - if your transmission is cold it will not shift into O/D and not lock the convertor at about 70km/h

Even if your transmission is the old hydraulic the O/D clutch is still tied to the ECU and keeps the solenoid energized preventing shifting into O/D - once the ECU will see the coolant temp sensor register heat - it will release the O/D clutch and the transmission will shift into O/D (4th gear)

Strange that the Toyota could not explain that to you, its transmission diagnosis 101 - I would recommend to stay away from them as they do not know what they are doing

[asifhashmi]

I think i got a clue of the issue... this car has an option of ECT (on/off) when switched on drags the car more than normal limit and i guess its a sort of sports mode ....not sure ne how... i sent it for some wiring problem of the auto indicator in the gear box since than i am having this unusual draging issue coz that option is not working now.
ne one has ne idea whether this cud be the problem

[Xulfiqar]

so you have the ECT - and not the fully hydraulic transmission.

The transmission has two main wiring connectors - one large which is the Park Neutral cut out and selector indicator its large and has about 6 or 8 wires. the other would be where the usual OD connector is in the hydraulic transmission - but in your case would have 3 wires instead of just 2, the 3 wires are coming from the ECU going to the shift solenoids inside the transmission.

The ECT button is directly connected to the ECU and not with the transmission. And the symptom/action you are talking about is very very normal - the transmission will not engage OD unless the engine is hot. If it was not operating correctly before it is now

The ECT will delay upshifts causing the transmission to hold its gears longer, going to Normal mode the tranny will quickly upshift causing the rpms to fall and cruise. All this is also affected by position of the Throttle Position Sensor also - The TPS is what dictates kickdown in your transmission - not the cable like you would naturally assume

[shaheerali007]

bro i faced the same problem wid my civic 05 prosmatic when i aftermarket transmition oil so i instantly go to honda and drain all the fluid and pour honda orignal fluid , honda person told me that after market fluids r thicker that can effect gear ratio . my sugation is to go toyota motor agin and use the fluid by toyota.

[asifhashmi]

@shaheermemon..... thanks the advise
@xulfiqar...... thanks alot to u 2 bro
the problem has been resolved... the issue was with the ECT option. it was somehow swtiched on and stuck there wasnt switching off. had to fix it manually now its working perfectly fine

[Xulfiqar]

bro i faced the same problem wid my civic 05 prosmatic when i aftermarket transmition oil so i instantly go to honda and drain all the fluid and pour honda orignal fluid , honda person told me that after market fluids r thicker that can effect gear ratio . my sugation is to go toyota motor agin and use the fluid by toyota.

toyota transmissions are so robust they will survive anything, and the oil needed for it is oldschool DX-IID - cheap and cheerful