Hi

I have been having a problem with the transmission shifting very hard. I just bought the truck a month ago not having the problem. It progressively got more frequent untill now all the time.

The trans was rebuilt 40,000 miles ago (I have the reciept). The TPS was replaced last year and i just replaced the VSS. When i replaced the VSS i checked the voltage at the connector and KOEO i got 4.98 volts constant, which i think means the wiring is good. Anyway i disconnected the battery for an hour. The problem wasn't fixed. I replaced the MLPS which had the updated connector and still didn't fix the problem.

I pulled the codes and got 111 which is system pass. And i got code 452 which is Computer detected an error in the VSS or PSOM signal during the last 80 warm-up cycles.

I am thinking that it must be the PSOM? But my speedometer and odometer work fine.

If so, how do i replace the PSOM and where can i find a new/another one?

Thanks,

-Greg

 

A salvage yard would be the best place to get one, you will have to buy the whole cluster and then take the PSOM out of it.
I am guessing that you have a 1992-1996 truck. So a PSOM out of any truck and maybe vans from 1992 to 1996 should work as far as I know.

Ford will not sell these but will replace it for about $400.00 and there is a bunch of paper work to fill out to conform to the federal law.

To replace you just take out you cluster, take it apart, unplug the PSOM and plug in the replacement, assemble the cluster and reinstall.

 

Thanks Subford,

Sorry, It is a 94 5.0 E4OD 4X4. If i replace the PSOM will my odometer reading be different and my 35 inch tires have to be reprogrammed?

Also, is there any guide to taking it out or is it simple when looking at the dashboard?

-Greg

 

Yes the odometer reading will be different (whatever the truck it came out of had) and you would have to reprogram for you tires unless you have Ford do it then they would (can) put your old odometer reading in it I think.

You also only get five shots at reprogramming it and some shots may have already been used up.

I can post a how to on taking it out if you go that route and want me too.

 

Yea, if it is not too much trouble.
Thanks,
-Greg

 

CAUTION:
The instrument cluster requires special handling to avoid damaging internal components. The cluster MUST be kept FACE UP or in the in-vehicle position. Leaving the cluster face down may result in a loss of dampening fluid used in the gauges. The lost fluid could stain the cluster face or result in excessive pointer waver.
Removal

1. Disconnect the battery ground cable.
2. Remove the cluster opening finish panels as outlined in «Section 01-12A» or «Section 01-12B», Instrument Panel and Console.
3. Remove the transmission indicator cable loop from the ball stud on the shift lever (automatic transmission equipped vehicles only).
4. Remove the thumb wheel bracket screw and detach bracket from steering column (automatic transmission equipped vehicles only).

http://i54.photobucket.com/albums/g9...d/Cluster1.gif

5. Remove four screws attaching the cluster to the instrument panel. Pull cluster out of instrument panel, bottom first, to rest on the steering column.
6. Disconnect the three electrical connectors and remove the instrument panel.

Installation

1. Position the cluster facing up on the steering column and connect the three electrical connectors. Position the instrument cluster in the instrument panel to engage locator pins.
2. Install the four screws attaching the cluster to the instrument panel.
3. Place the transmission selector cable loop on the shift lever ball stud (automatic transmission equipped vehicles only).
4. Position thumb wheel bracket on the right side of the steering column and secure screw (automatic transmission equipped vehicles only).
5. Adjust the automatic transmission selector lever indicator (if equipped).
6. Install the cluster opening finish panels as outlined in «Section 01-12A» or «Section 01-12B», Instrument Panel and Console.
7. Connect the battery negative cable.

NOTE:
When the battery is disconnected and reconnected, some abnormal drive symptoms may occur while the EEC processor relearns its adaptive strategy. The vehicle may need to be driven 10 miles or more to relearn the strategy.

Connect the battery ground cable.

 

The above has been updated for 1994 and here is your Dash Diagrams.

http://i54.photobucket.com/albums/g9...d/1994Dash.gif

 

Thanks again subford!

I have to find a cluster/PSOM from a junkyard to swap out first. I hope this is my problem because i really want to drive the truck.
-Greg

 

Good News!

I finally got a cluster from a junkyard.
I installed it with subford's directions (Thank You!)
Now the truck is driving great! No more hard shifts, smooth through all gears!

One question though. I wanted to just switch the PSOM but i couldn't figure out how to take the cluster apart. I pulled off the plastic cover, but couldn't figure out how to take off the faceplates for the gauges. I didn't see anyway into the cluster from the back either.

-Greg

 

This article details how to take apart the cluster:

https://www.ford-trucks.com/article/idx/17/126/article/Installing_An_OEM_Tachometer_In_A_19921996_F150_Or _Bronco.html

 

Playing_Tough when you said:
"When i replaced the VSS i checked the voltage at the connector and KOEO i got 4.98 volts constant, which i think means the wiring is good."

Are you talking about the connector the connects to the vss it self?

 

Yea, I pulled the connector off the VSS and used a multimeter on the two prongs in the connector to get the reading. I thought maybe the wires could have been severed somewhere and since i got voltage i knew the wires were okay. I guess there could have still been a intermittent short somewhere, but there isn't. It was the PSOM.

-Greg