Overdrive light flashing....????

steve44england said:

Hi,wondered if anyone can help please?

I've got a 96 4.6V8 Mustang,and the overdrive light keeps flashing at low speeds.
The handbook says it is a gearbox fault warning.....the Haynes manual doesn't say ANYTHING about it!!!

The oil level is fine...the gearbox oil and filter have recently been changed.

If anyone has any ideas where to look or how to find what the fault is it would really help. Oh, and there are no gearbox fault codes showing.

Thanks in advance,
Steve

Click to expand...

Get yourself a factory service manual. This tells you "everything".
A Haynes manual is about useless.

i had this when i lost my trany on my old car, i lost 3 gear and o/d.

when did it start and what happen?
have you had your ecm out lately?
and if you hit your od button does it do anything?

The same thing happened to me with my 1994 LX Mustang. Just out of curiousity, does your transmission shift hard under full-throttle acceleration?
Anyway, it turned out my transmission had to be rebuilt, and rebuilding an AOD-E (which I assume is what you have) was about $1400.

Hope you don't have the same problem!

steve44england:

First, check, check, and re-check the fluid level. It is difficult to measure so do it a few times to make sure you get an accurate level reading.

If you have never had the transmission fluid and filter changed, then do it. And repeat every 20,000 miles. Sooner than the manual says, just like we all change our oil sooner than the manual requires. If the fluid is brown and smells burnt, then you (a) need to change the fluid and (b) may have a serious problem.

If your speedo is erratic, too, then check the plastic gear on the vehicle speed sensor (VSS) on the driver's side of the transmission. If it is chewed up, then the PCM will not get the correct signal when compared to the output shaft sensor (OSS) and will show a fault. It is also possible that the coolant shorted out one of these sensors (they are supposed to be waterproof).

I agree that the service manual (published by ATSG) is a good thing to have. The problem is that you probably don't have the electronic service tools to run the diagnostics. At least you will know what your technician is looking for!

Check out the "Transmissions 101" articles in the Tech Articles section of TCCoA.com. There is a chapter on troubleshooting that might be helpful.

Good luck.