# 99 Psd Od Light Flashing!



## bluebyu62 (Jan 8, 2001)

Hi guys, just the other night my Overdrive light began flashing on my 99' F250 PSD w/ automatic trans. Began flashing after i drove about 25 minutes. Also began shifting very hard. I shut it off, then started it back up and disengaged the overdrive. Has not done it while in regular drive. I tried disconnecting the batteries and reconnecting them an hour later to clear the computer of any codes but that was no help. Any help would be greatly appreciated. Thank you.


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## 99SDPSD (Jan 20, 2001)

The flashing O.D. of light Indicates the tranny is Ill take it to the dealer and have it checked for codes.


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## bluebyu62 (Jan 8, 2001)

Thanks, the dealer is already checking it out.


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## bytor (Nov 8, 2001)

Is the OD light still flashing after you "rebooted" the truck?

I frequently get the OD light flashing, and at the same time the speedo doesn't work. Most of the time, this happens if I started the truck too quickly. Like if I've been driving a gas-engined vehicle for a while and forget to wait in the diesel.

I've had it flash at me (and no speedo) a few times when going down the road and when I know full well it was working a few miles back.

In my case, a reboot or two always does the trick, so I haven't worried about it. Is it a harbinger of worse to come?

It's done this since day one.


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## 99SDPSD (Jan 20, 2001)

If the od light is flashing and the speedo isnt working it means that the Speed Sensor in the top of the rear end is on its way out . Go have it checked for codes and verify that the speed sensor is NG.


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