Super Duty & Heavy Duty1999 to current Ford F250, F350, F450 and F550 Super Duty with diesel V8 and gas V8 and V10 engines
Welcome to Ford-Trucks Forums!
Welcome to Ford-Trucks.com.
You are currently viewing our forums as a guest, which gives you limited access to view most discussions and access our other features. By joining our community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join the Ford-Trucks Forums community today!
O/D off light is flashing on the shift lever. In a drive gear (R, OD, D2, D1) there is very low power when giving it gas, more so from a stop. In P and N, I can rev the motor with no obvious issues. In O/D, I can't even get forward momentum going from a stop when on a slight incline. When on flat ground and in O/D, flooring the gas only gets me going a few MPH and RPMs don't go above 1500ish. When selecting 1st or 2nd, the truck still struggles a bit from a stop but does get up and going.
What happened leading up to the issue:
I was on the freeway driving about 80MPH without cruise control se,t and with O/D on as usual, when the blinking O/D off light caught my attention. Not knowing at the time that this was a transmission problem light, I started pushing and holding on the O/D on/off button to try and get it to stop. Probably about a minute later, I realized I was losing speed even when giving more throttle so pulled over to the shoulder. I shut the truck off and restarted it, noted the Service Engine Soon light was now on, then I put it in O/D and gave it gas but only got going a couple MPH which it sounds like the engine was choking/struggling. I then tried D1 and D2 and, while still struggling a bit from stop, was able to accelerate up to 35+ MPH.
System Purge Control
O2 Heater Circuit
(Bank 1. Sensor 1)
O2 Heater Circuit
(Bank 2. Sensor 1)
Transmission fluid check looks good (full and red)
Checked fuse 23 of the Central Junction Box
Held a ground wire to botton of Transmission pan and to the frame while I started the truck, O/D light still flashing
Wiring looks good coming to the plug on the driver side of the transmission
- No "Service Engine Soon" or blinking O/D off light prior to all this happening.
- I don't believe I'm getting 1st gear. I don't recall if I got my speed up to 30+ MPH while in D1, but while in D2 I never noticed a shift from stop to ~35MPH. At 35MPH, my RPMs were around 2500 I believe.
- While cruising at 35MPH in D2, shifting to O/D results in lost power. I had to stay in D2 all the way home.
To do (I believe):
1. Check shift solenoids (looking for DIY info)
2. Check shift solenoid pack (looking for DIY info)
3. Check TCC solenoid (looking for for DIY info)
I'll be browsing this forum for more tips, but in the meantime wanted to throw up a post with my specific symptoms in hopes of getting some feedback. I won't be diving too deep into this before giving in and taking to a shop but wanted to try and eliminate any of the "simple" things first.
Any links to posts/pages about how to check some of the specifics would be appreciated. It sounds like there are a couple shift solenoids to check as well as a solenoid pack (how best to check these out, I'm still looking for)?
It is not any of the solenoids unless several failed at the same time. You have a wiring issue, that's why you have all electrical circuit failures. Somehow the wiring harness was damaged. You might find the problem if you trace the harness from the PCM near the brake booster to the transmission.
__________________ Mark Former Ford Automatic Transmission Engineer
“The good thing about science is that it's true whether or not you believe in it.” ― Neil deGrasse Tyson
This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. Ford® is a registered trademark of the Ford Motor Company.