I purchased this truck back in July. The OD light always blinked. But the function worked then and still does today. I took it in to the shop about 3 months ago because the transmission started to delay when shifting gears. The guy said we could try switching the controller pack, but it would most likely need to be rebuilt. I told him about that light and he said it might fix it, but if it does not, we will go for a full rebuild. Since I would have probably ended up purchasing a controller pack anyway when doing a rebuild, I decided to try it. It didn't fix the shifting problem (not related to the OD light) so I said lets do a rebuild.

After the rebuild, the transmission feels great. I can still control the overdrive function, but the light still blinks. I ended up having an engine rebuld right after, so i just got it back. Still blinking though. Anyone know what the rpoblem is?

 

You need to pull codes on it, it could be a few different things.

 

Ok. They still have the truck. If they can't figure it out, I'll buy a code reader. I think i mentioned it to them before, but they said its so old that they don't have or use that kind of reader anymore. I don't want to push them to get one, it might "void" my 2 recent truck transmission warranties if you know what i mean.

 

This is why I think the old C6 with a OD is a much better set up.


My E4OD was acting up and I thought I needed major repairs and the Guru's on this site fixed it. On mine the tranny is wired into the cab light and the cab light was shorting out so the circuit kept blowing fuses and the tranny would not shift correctly with the OD blink going off. Real stupid layout from the factory....

 

You can use a Ford specific OBDI code reader, but it's not required. Here's how to get blink codes:
Ford ? OBD/OBD2 Trouble Codes