Limp mode P1700, P0720, P2106?

JOVANSCOTT

MEMBER
2004 FORD EXPLORER
V8
4WD
AUTOMATIC
210,000 MILES

Had transmission codes to replace the OSS and add more fluid. It's still in limp mode, the codes point to possible TCM malfunction, P1700, P0720, P2106. Scan tool detected all sensors were reading correctly. I apparently relaced the intermediate sensor. Should I replace the OSS even though I'm receiving the correct readings. And how do I replace the TCM?

Friday, April 10th, 2026 AT 9:07 PM

3 Replies

KEN L

MASTER CERTIFIED MECHANIC
55,383 POSTS

I would start by checking the transmission fluid level ad condition, see if the fluid is burnt which means the transmission is bad and needs to be rebuilt, but we should replace the OSS as well and then clear the codes if the fluid is okay.

P0720 - the PCM is unhappy with the output shaft speed (OSS) sensor circuit/signal
P2106 - is usually a secondary “failsafe / forced limited power” code
P1700 - points to a transmission fault request to the PCM.

Here is the location of the output speed sensor so you can swap it out. Check out the images (below). Let us know how it goes

Image (Click to make bigger)

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Saturday, April 11th, 2026 AT 8:25 AM

JOVANSCOTT

MEMBER
2 POSTS

Thanks, I checked and replaced the fluid and those were the codes after. My next step was to replace the OSS, however the scan tool I used to check during operation showed all the sensor were sending back the correct numbers. In the case that the TCM is the problem, I was wondering how to replace it if the reset methods don't work.

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Saturday, April 11th, 2026 AT 8:34 AM

KEN L