I'm having trouble with my ABS light on, speedo not working and E4OD trans not shifting. I originally posted just asking for help getting the VSS out, but a little more searching gave me this thread that made me decide to leave that for another day. But now I'm having worse troubles than I was before. See the second post for my current questions. The rest of this post is my original question when the thread title was asking about tricks to remove a stuck VSS.

Original post:

I just started trying to remove the VSS from my '97 F-250HD. I was able to get the electrical connector off without breaking anything, and the hold-down bolt came out easily enough. But is there any trick for getting the sensor out of the axle housing? I assume it just slipped in 21 years ago and now it's rusted in place. With the two fins on the axle housing on either side if it I can't really get at it very easily. And I don't want to brake anything off and be worse off than I am now.

Any suggestions?

 

OK, new issue. Or actually backing up to the old issue. About a year ago my ABS light started coming on, at first occasionally, but then more often and lately almost all the time. At first I also had one trip where the speedo would occasionally drop to zero. The speed control would panic when that happened, but otherwise there were no issues (the E4OD trans stayed in OD). But since that one trip it's just been the ABS light (and presumably the ABS has not been working).

Then on Saturday the ABS light started flashing and the speed control quit working entirely. Also I couldn't get the trans to shift out of park unless I shut the engine off and put the key in the "off" position (between "lock" and "run"). I thought that was unrelated, but Google told me that the flashing ABS light and not being able to get the shifter out of park with the engine running were both due to fuse 13 being blown. I checked, and yes, fuse 13 was blown. So I replaced it.

But before I figured that out I had bought a new VSS and tried to take the old one out. When I couldn't get it out easily enough I decided to just hook the old one back up for now, check fuse 13 and go from there. When I took it for a test drive the ABS light was on (not flashing) and it shifted out of park with the engine running. But now the speedo is just sitting at 0 and the trans won't shift. I can manually select 1st, 2nd or reverse, but if I put in in OD it just stays in 1st (I haven't tried shutting off OD, but I'd guess it'll stay in 1st there too).

So any guesses what my real problem is? I'm thinking I probably should try to replace the VSS, but I need the truck tomorrow evening, and I can limp by with 1st 2nd and reverse, so I'm not going to do anything with it tonight or tomorrow. But I do need to get it fixed pretty soon, so I'd sure appreciate anyone who can help point me in the right direction.

 

VSS Testing:

Put jack stands under the rear axle.
There should not be a plug under the dash for this system other than the plug for the RABS module.
The plug should be at the drivers hood hinge just aft of the EEC Self-Test plug.
Put a A/C volt meter on this plug, it only has two wires.
Run the truck up to 30 MPH.
Does the voltage increase smoothly and continuously from 0 to approximately 3.5 volts AC as vehicle speed increases from 0 to 48 km/h (0 to 30 mph) at the plug?
If not unplug the RABS module and see if you get it now.
If not unplug the PSOM also, do you get the VAC now?
If not change out the VSS sensor at the rear end.
If the wiring is OK and you still do not get the voltage reading then you may have a bad tone ring or bearings in the rear end.


Given your symptoms I would suspect the VSS or the wiring is bad.

 

 

Thanks. I think I'll start by throwing a random part at it. Well, not quite random. I already have a new VSS, and since that seems like a good bet, and since I don't have anyone to help me run those tests, I think I'll take a swing at it and hope for a hit. But if this strikes out I'll be very glad to have that test sequence.

Mine is in the diff, and I'm quite sure that I have the correct one. I haven't actually replaced it yet, so it's still the original one that might not be working. And yes, I bought a new Motorcraft VSS.

 

 

To (hopefully) close this out, I replaced the VSS and my problems went away!

To recap (since it's kind of spread out above), my symptoms were the ABS light on most of the time (for over a year), the ABS light flashing and the trans not shifting out of park with the engine running, the speed control not working, the speedo sitting at zero occasionally, and the trans at first shifting very hard, but later not shifting at all (all of these last symptoms only started recently).

Replacing fuse 13 solved the flashing ABS light (it went back to being on steady) and the trans not shifting out of park, but none of the other issues (although I never checked the speed control after that).

Replacing the VSS took care of all the rest of the issues. ABS light is off, trans shifts fine, speedo works and speed control works. I haven't driven it much since replacing the VSS, so if anything changes I'll update this thread. But otherwise assume it's all good!


And to help anyone else stumbling through the same issues:

When the trans won't shift out of park with the engine running it still seems to fine with the key in the "off" position. So turn the keey off, shift it to neutral and then start it.

And when the trans won't shift automatically, it will still go into 1st, 2nd or reverse when you put the shift lever in those positions. So you can still limp it home.

And getting the VSS can be a real bugger! I found help in this thread that helped, and described what I had to do in detail (remove the diff cover and driver's-side diff bearing cap, and bend the tip of a long thin screwdriver to push it out from the inside).