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Milage is 255,000K. It makes no difference if the OD switch is on or off or if I go through the gears manually. I did replace the speed sensor because the dealer told me that "might" be the problem. It wasn't. The speedometer does fluxuate very, very slightly at about 110K but seems fine other than that. I tried the codes again and there are still none coming up. If I disconnect one of them then the SES light comes on and goes off when I reconnect it. What other speedometer troubles have you heard tell of?
Originally posted by guitar_god2003 I tried the codes again and there are still none coming up. If I disconnect one of them then the SES light comes on and goes off when I reconnect it.
"None"? Like not even the "everything's OK" code? If you don't get ANY code, then you didn't actually pull them.
And what are you disconnecting to get the SES light to come on?
In their iniinite wisdom, Ford designed their computers to take a converted signal from the speedometer / guage cluster. The problem is that the clusters went bad, telling the computer the truck was going something like 180 MPH.
But yeah, you ought to pull the codes correctly, or find out why you can't.
Come on guys....how dumb do you think I am. The only code coming up is the one saying that everything is OK. To me that means there are no trouble codes coming up. To check to see if the computer will set a code I disconnected sensors then reconnected them. I have been working on this problem for a while even will the help of a Haynes manual and a Chilton on as well. The problem is that they don't have a diagnosis for the problem with my truck.
I just did some reading on the PSOM from the posts that you mentioned. When I had my truck into the dealer they told me that there was a code 452 (insufficent input from VSS) coming up. I checked the wiring on the rearend and I'm getting the right voltage and the wire going to the PSOM seems fine. In other words I disconnected the speed sensor and my ABS light came on and stayed on until I reconnected it.
The posts said that the signal wire from the speed sensor goes to the PSOM first and then to the computer. Is there any way to test the PSOM to see if it is bad? Like I said before the only fluxuating of the speedometer is at about 100 + kilometers but I never paid much attention to it. Could a bad PSOM cause the transmission to go into lock-up early and bad shift points?
Yes, a bad PSOM will do that. What revision is yours? I have an 08 in my truck which has worked fine ever since I got it from a junkyard, but I don't have an electronic transmission. My cruise has always worked fine, though...
Originally posted by guitar_god2003 how dumb do you think I am.
I didn't say you were dumb, but when you say "there are still none coming up", I have to wonder if you're not pulling them right. 111 is a "Diagnostic Trouble Code" according to Ford, and I've posted plenty of responses to people who used the same words as you because they weren't seeing ANY codes.
I understand what you mean. The revision for mine is 08 just like yours. I checked it just like you said in one of your posts. I also checked to see if it was calibrated right and it is.
So if the PSOM is bad it will cause a code 452 and cause the transmission to go into "lock-up"/"lock-out" too early?
I've never read up on the exact symptoms of a bad PSOM because I've never had trouble out of mine and I don't have an electronic automatic transmission, but the EEC does need a good VSS signal to control the transmission properly. You should be able to diagnose it by just unplugging the PSOM and jumping the input (Or/LB or R/Pk) to the output (Gy/Bk). That'll send the raw ABS sensor signal to the EEC. If that doesn't work, pick up another PSOM from a junkyard, eBay, or the classifieds here. You should be able to find one for under $40 or a whole instrument cluster for under $90.
Do you mean unplug the connector, jump out those wires then test drive it with te PSOM disconnected? This will send the VSS signal directly to the computer letting me know if the problem is the PSOM? The Orange/Light Blue or Red/Pink is the input wire from the abs sensor (VSS) and the Grey/Black is the output wire from the PSOM to the EEC, right.