05 expy 5.4 tranny issue

[Diagenic]

My 05 Expy 5.4 4wd 100000miles started to fail when putting it into drive. Revs up but dont go forward at the matching speed. Got code p0720 and followed by p0126. Have checked the ohm resistance on the output speed sensor to be 439, since that sensor relates to p0720 code. Today i changed tranny fluid and filter to be on the safe side. Cleaned the sensor and put it back, checked the pcm connectors for dirt. Car still goes bad. When i put in drive, no clank sound as it usually does. Goes forward but revs up without the speed to match it. Speedo functions ok. Reverse gear also. O/D light blinks also. Have ordered a new output speed sensor. Dont know if this will fix the problem or not. Anyone who have had similar problems?

 

[docraymund]

If you put it in drive, it should immediately move forward when you step on the gas. If there's a delay of a few seconds, your transmission may be faulty.


You could also try reading this might help:

https://www.ford-trucks.com/forums/1468303-output-shaft-sensor.html

 

[Bedrck47]

Are you certain about code P0126 as that is for Insufficient Coolant Temperature For Stable Operation

 

[Diagenic]

Bedrck47: Sorry it was p2106, limp mode. Docraymund: Speedo works fine. It dont engange properly in drive, just reverse.

 

[Bedrck47]

Some info for you

P2106 - Throttle Actuator Control (TAC) System - Forced Limited Power
Description: The TAC system is in the failure mode effects management (FMEM) mode of forced limited power. This DTC indicates the FMEM action is in effect due to a failure in an electronic throttle control (ETC) related component or module.
Possible Causes:

• Unplugged motor, circuits shorted to power.
• TAC motor open, unplugged motor, circuits shorted to power.
• TAC motor stuck open or closed.
• Mass air flow (MAF) sensor fault.
• Throttle position (TP) sensor fault.
• Module communications network concerns.
• Manifold absolute pressure (MAP) sensor fault (Vehicles with an EGR system module [ESM]).
• Output shaft speed (OSS) sensor fault (Crown Victoria, Expedition, Explorer, F-150 4.6L and 5.4L, Grand Marquis, LS, Mountaineer, Mustang 4.6L automatic, Thunderbird, Town Car).
• Turbine shaft speed (TSS) sensor fault (Crown Victoria, Expedition, Explorer, F-150 4.6L and 5.4L, Grand Marquis, LS, Mountaineer, Mustang 4.6L automatic, Thunderbird, Town Car).
• Anti-lock brake system (ABS) fault (Crown Victoria, Expedition, Explorer, F-150 4.6L and 5.4L, Grand Marquis, LS, Mountaineer, Mustang 4.6L automatic, Thunderbird, Town Car).

Diagnostic Aids: This DTC is an informational DTC and can be set in combination with a number of other DTCs which are causing the FMEM. Diagnose any accompanying powertrain DTCs first. For Crown Victoria, Expedition, Explorer, F-150 4.6L and 5.4L, Grand Marquis, LS, Mustang 4.6L automatic, Thunderbird, and Town Car with only P2106, repair any ABS DTCs, ABS related DTCs in other modules or vehicle communication concerns using the appropriate section of the Workshop Manual.
Application Key On Engine Off Key On Engine Running Continuous Memory
All GO to QE1


Since you have P0720 I would repair that first and see if that solves the problem

 

[Bedrck47]

P0720 - Output Shaft Speed (OSS) Sensor Circuit
Description: The OSS sensor inputs a signal to the powertrain control module (PCM) based on the speed of the output shaft of the transmission. The PCM compares this signal with the signal of the vehicle speed sensor (VSS) or transfer case speed sensor (TCSS) and determines the correct tire size and axle gear ratio.
Possible Causes:

• OSS sensor circuit short to GND.
• OSS sensor circuit short to PWR.
• OSS sensor circuit open.
• Damaged OSS sensor.

Diagnostic Aids: Verify the sensor signal output varies with the vehicle speed.
Application Key On Engine Off Key On Engine Running Continuous Memory
Manual transmission — — GO to TJ1
All others Refer to the Workshop Manual Section 307-01 Automatic Transmission.

 

[Bedrck47]

P0720 OSS Insufficient input from output shaft speed sensor PCM detected a loss of OSS signal during operation. Harsh shifts, abnormal shift schedule, no torque converter clutch activation. Go To Pinpoint Test E .

 

[Diagenic]

bedrck47:do you have a link to pinpoint test E? Measured the OSS to 439 ohms.

 

[Bedrck47]

Yes Need your e=mail address in order to send it to you

 

[Diagenic]

[email protected]

Thanks!

 

[Bedrck47]

sent

 

[Diagenic]

Will change the oss tomorrow, sensor was 32$ shipping was 95$ to Norway

 

[stamp11127]

Doubt the OSS is your problem since it is only an input sensor to the pcm. If you had a manual transmission with the clutch pedal depressed you would have the same symptoms you are having. Since it drives fine in reverse that tells you there is sufficient output from the pump since reverse requires the most pressure.

To venture a guess your problem may be with solenoids, bands or clutches. Did you drop the pan when you changed fluid? If so was there a bunch of dark gray goop in it?

 

[Diagenic]

Doubt the OSS is your problem since it is only an input sensor to the pcm. If you had a manual transmission with the clutch pedal depressed you would have the same symptoms you are having. Since it drives fine in reverse that tells you there is sufficient output from the pump since reverse requires the most pressure.

To venture a guess your problem may be with solenoids, bands or clutches. Did you drop the pan when you changed fluid? If so was there a bunch of dark gray goop in it?

I dropped the pan and the oil was red and clean, no dark gray goop, no metal shavings. No bad smell. Oil was changed 2500 miles ago. Changed the Oss today, reset errocodes. Same shit as before. Goes into reverse as usual, when i put it in drive it takes long time for it to engage, and then the car just rolls forward without any power. Any suggestions ?

 

[stamp11127]

Without transmission rebuilding experience and tools there isn't much you can do. Slow engagement could be failing solenoids or pressure leaks in the hydraulic circuits of the valve body.
Shipping costs for a rebuilt trans probably is more than the Expy is worth. Are there any Ford F150's over there in the junk yards?

 

[Diagenic]

Current value is around 40000$ new price in 05 was 180000$ crazy prices. No F150 in junkyards over here. Was sold 25 05 Expys back then. After that none.