Output Speed Sensor or Transmission?


Old 07-21-14, 02:43 PM
Thread Starter
Join Date: Feb 2008
Location: Southern Illinois
Posts: 281
Output Speed Sensor or Transmission?

The automatic transmission in my 2005 Ford Escape was rebuilt about eighteen months ago and six month ago we replaced the transfer case. Both services were done by the same garage which specializes in transmissions. Though mine was the first Escape that they could remember doing.

When the transmission went, the car just suddenly stopped going as we went down the road. When the transfer case went, it wouldn't backup, but the SUV went forward without any problems.

One day last week, I noticed it "slipping" as I took off from stoplights, but the car successfully completed my errands and it was just something I put at the back of my mind because it didn't happen on the next couple of trips. Then a day or two later, my wife drove it someplace, where it was going to be parked overnight and she said it "slipped" from the stoplights and when she got to her destination, it would only begrudgingly backup and that was with the accelerator pushed to the max.

The next day I went to retrieve the car and it gave me no problems going backwards or forward. It didn't even slip, but the Check Engine light was illuminated, so I took it to Autozone and got them to run the code. What I got was PO720 - "output speed sensor insufficient input. Vehicle speed sensor over 1 MPH while the output speed sensor did not agree. Probable cause: failed output speed sensor. Open or shorted circuit condition".

Because the car was still working and the garages are closed on the weekend, I brought it home and have ran a few errands in the immediate vicinity without any problems until this afternoon, when it slipped a couple of times, then it wouldn't "catch", so I pulled it off the road until I could decide what to do.

I've seen the videos on replacing the output speed sensor and that is something I could do myself, though I might take it to a mechanic because it'd be easier for him to do with a lift. If that's all it is, I would take it to one mechanic, but if anyone more knowledgeable were willing to offer advice and if they don't think the speed sensor would prevent it from going in reverse, I'd have to consider taking it to the transmission specialist who has already worked on it twice, whose MO appears to be to drop the pan and take the car out of commission for a week before giving me a bill. (The transfer case parts are still under warranty, so if that's the problem, it probably should go to him)

Any advice would be appreciated.

Edited to Add: The transmission fluid checks full, appears pink on the cloth and doesn't smell burnt. It smells like transmission fluid when you sniff the stick.
Sponsored Links
Old 07-21-14, 02:49 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: NJ - USA
Posts: 42,995
it would only begrudgingly backup and that was with the accelerator pushed to the max.
That must have sounded delightful.

I would think you need to take it back to the place that did the rebuild work.

I don't think the output sensor is defective. The vehicle wasn't moving when the transmission was in gear and and at quite a throttle.
Old 07-21-14, 03:02 PM
Thread Starter
Join Date: Feb 2008
Location: Southern Illinois
Posts: 281
She was out at a parking lot beside a lake, so I'm sure the delightful sound carried.

If it's the transfer case, I'd sort of have to because of the warranty and he might be the only place in town which rebuilds transmissions, but if it could be the speed sensor that is causing the problems, it appears to be something I could do myself or a different garage could do faster and cheaper.

Right now it's sitting beside the road and I don't know whether to take it a mile north to the transmission shop, a mile south to my regular mechanic or a mile east to the house.

Just saw your edit: She doesn't remember the light being on when she was trying to backup and I hadn't seen it with the earlier slipping, but it's been on steady since.
Old 07-21-14, 03:33 PM
Thread Starter
Join Date: Feb 2008
Location: Southern Illinois
Posts: 281
Update: Based upon my paperwork, it doesn't appear that there's a warranty on the used transfer case, but it is still under warranty for the second rebuild. I thought, but wasn't certain until just now, but we've had the transmission on this vehicle rebuilt twice by this same shop. Though the second rebuild wasn't within the warranty period or something because it still cost quite a lot.

The dates in the first post are wrong. The first rebuild was like twenty months ago and the second was six, while the transfer case was just three months ago.
Old 07-21-14, 04:01 PM
Gunguy45's Avatar
Super Moderator
Join Date: Dec 2007
Location: USA
Posts: 20,785
Well, you should have a warranty, so I'd go back to the trans place. The trans in these vehicles are just terrible. I had a 2001 Tribute (same basic drivetrain) and it had a major repair, then 9 months later a rebuild, and then 2 yrs later a complete overhaul including valve body and torque converter.

If you do some research you'll find thet there are many available upgrades to keep them running. Valve bodies to handle the pressure issues they have, T/Cs with different construction, solenoids that are better designed. If they just used stock parts, thats not good.

Normally, with a trans issue, the OD (4WD?) light will flash or illuminate. Since you are getting a CE light, it could be just a sensor.
Old 07-21-14, 04:12 PM
Thread Starter
Join Date: Feb 2008
Location: Southern Illinois
Posts: 281
The ABS light has been steady and the 4WD light has been blinking seven times (if I'm remembering correctly) every minute for the past few months. The combo indicates that the ABS sensor has gone bad and the (other) mechanic checked out the brakes and said it was the sensor, but that he'd have to order one and because I've not been in a hurry, I've just let the light blink.

IOW: The 4WD light was already blinking and I didn't notice a change. Once or twice, I did find the overdrive engaged (or disengaged, whichever you have with the light), but I assumed someone accidentally hit it and it wasn't frequent or recent enough for me to make the connection.
Old 07-21-14, 05:12 PM
Thread Starter
Join Date: Feb 2008
Location: Southern Illinois
Posts: 281
Another Update: We just went to get it. After sitting for three hours, the vehicle started out okay, but then about a hundred yards down the road, it gave out. Once it was off the road, I tried reverse, but it wouldn't back up.

I really wish it was something besides the transmission because we've already rebuilt this one twice and though it's under warranty, the transmission place is a small shop and I suspect it would still cost more than an OSS or VSS sensor. Any more thoughts or encouragement would be appreciated.


Thread Tools
Search this Thread
Display Modes
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -7. The time now is 02:14 AM.