92, F150, 4x4, auto. The speedometer is not working and it is shifting really hard. I pulled the codes and it showed 452 o,c,r, and 539.I checked all the fuses and changed the abs sensor on the rear end housing and it didn't help. Still doing the same thing. Any ideas?

 

Moved to proper forum.

 

Again, I see three digit codes from a '92. Were the 3 digit OBD-I's only available on trucks with automatic trannies?

Sounds to me like the VSS bit the bullet. Albeit, I don't think the VSS affects the shifting on anything other than the E4OD trannies. At best, you'll have the AOD in the '92, unless I'm badly mistaken. The C6 will shift really hard, and will normally skip 2nd gear if the modulator valve is shot. Normally, it starts sucking the tranny fluid out when this happens too, because the most common failure is the diaphram in the operator located at the tail of the tranny on the passenger side. On top of feeding your tranny fluid to your engine via the vacuum system, you'll want to fix it soon, or it'll burn the 3rd gear clutches pretty quickly without second. I had this happen on my Thunderbucket just recently. I'm not familiar with the AOD, so have no idea how shifting is modulated on it.

The VSS (vehicle speed sensor) is on the rear differential housing, right up on top. Where this might affect idle speed when slowing down, or fuel economy while highway driving, I don't think it would affect the AOD tranny, and certainly not a C6. But, it should fix your speedo problem. It may just be a loose or corroded connection. It's a 4x4, so chances are it's been in some pretty nasty mud a few times and water/mud has gotten in the connector.

What kind of tranny does it have? Gonna have to look and give us a little more info for us to help.

 

Trans code on the door is E. Numbers from the tag on transfer case H141 3135663 106892 F2TAAB

 

No. My dad's 92 4.9 5 speed outputs 3 digit codes.

The E4OD was available before 92 as well.

 

I am on the road again. Went to the salvage and got an instrument cluster ($65) and replaced it in about 2 hours. Speedometer is back working and transmission is shifting fine. Thanks to all who replied.

 

Hmmmm, so what we're saying, is that I got a '92 with a leftover 2-digit code ECM? I guess it all depends on where the truck was assembled as to which code system it has, i.e., which assembly plant still had a bunch of older ECM's on the shelf when they switched model years.

 

I'm not really sure if there is any rhyme or reason for what computer output what type of codes.