Pull the ABS codes too which are different from the ECU ones. There is 2 connectors under the glove box - the one nearest the passenger door is the ABS one (the other is to reprogram the speedo). It'll be a spade-receptacle type connector on about 5" of wire clipped to the bottom lip of the dash.

Two warning lamps are located on the instrument panel to alert the driver to a system malfunction. The red brake warning lamp is used to indicate conventional brake system malfunctions such as low fluid level, parking brake applied and low vacuum conditions (diesel engines only). The yellow anti-lock system warning lamp is used to indicate proper warning lamp circuit operation (2 second illumination with ignition On or engine cranking). If yellow lamp comes on while vehicle is being driven, it is alerting the driver of an anti-lock system malfunction and yellow lamp can then be used to access flashout codes. This self-test feature contains 13 codes to indicate area of system malfunction. When a malfunction is detected within the system, the computer module will shutdown the anti-lock system and illuminate the yellow warning lamp on the instrument panel. This will permit normal braking and at the same time will store a code in the system memory which can be retrieved by grounding the diagnostic connector of the computer module and counting the number of flashes of the yellow light. If the ignition is turned off before diagnosis is performed, the code stored will be lost. In this case, the vehicle must be started and driven to reproduce the condition. If more than one fault exists, only the first code recorded will be displayed. Additional codes will output only after the first fault has been corrected.


1. If ignition switch has been placed in Off position, start engine and operate vehicle in an effort to recreate the service condition.
2. Connect suitable jumper wire to the diagnostic connector, then momentarily ground jumper wire to chassis. As ground connection is made and broken, the yellow warning lamp will begin to flash the fault code.
3. Fault codes will be displayed as short flashes and a long flash. As an example, two short flashes and one long flash would indicated flashout code 3. Observe flashout code several times to avoid misreading. The code will continue to flash until the ignition is placed in the Off position.
4. Refer to flashout code charts, and diagnostic charts, for diagnostic and testing procedures.
5. After correcting service condition, the vehicle may be operated to obtain the next flashout code as necessary.
6. After all flashout codes have been obtained and service conditions corrected, remove jumper wire from diagnostic connector.

Then look up the code here;

 

i had to replace my ABS control module which is located under the radiator reserve tank. if you pull off the connector and jump some of the pins that are related to the speedo function then drive it down the street the speedo should work and will tell you that module needs replaced. I forget which pins it was though. i will try to dig up that info

ok i found the info. pull the connector off of the control module then jumper 14 to 21, & 39 to 22. pay real close attention to the numbering of the pins its a little confusing at first. I just used some 16gauge wire cut short for jumpers. once i did this i was able to drive down the street and my speedo worked.

 

Thanks for the replys. My ABS module does not have that many pins nor are the marked in any way to try that test.

Did I mention the problem started after driving through a big body of water on the road (poor drainage on road partially floods right lane.) I did find this, anybody have any experience with this module? It doesn't mention the speedo not working as a symptom though.

Water Intrusion of MLP/TR Sensor TSB 95-2-12 by Ford for 89-94
01/30/95
TRANSMISSION - E40D - DIAGNOSTIC TROUBLE CODES - WATER INTRUSION OF THE MLP/TR SENSOR
TRANSMISSION - E40D - POSSIBLE WATER INTRUSION INTO THE MLP/TR SENSOR CAUSING SHIFT CONCERNS AND/OR HARSH ENGAGEMENT CONCERNS
TRANSMISSlON - E40D - SHIFT CONCERNS AND/OR HARSH ENGAGEMENT CONCERNS DUE TO WATER INTRUSION OF THE MLP/TR SENSOR
1989-94 BRONCO, ECONOLINE, F-150-350 SERIES, F-47, F-53, F-59
ISSUE: Some vehicles may exhibit a shift concern and/or a harsh engagement concern due to water intrusion into the MLP/TR sensor and vehicle harness. There may also be a number of different DTC's along with those concerns.
ACTION: Replace the MLP/TR sensor and vehicle harness connector if signs of water penetration are evident. Refer to the following for service details.
SERVICE PROCEDURE
1. Verify the customer concern.
2. Perform normal on-board diagnostics.
3. Inspect the MLP/TR sensor for signs of water contamination.
4. If water penetration is present and/or DTC's have been set, replace the MLP/TR sensor and the vehicle harness connector with the TR Sensor Service Kit (F5TZ-7A247-A).
The TR Service Kit contains:
One (1) TR Sensor
One (1) Connector Assembly
One (1) "Red" Pin Separator Plate
One (1) 6-Pin Grommet
One (1) 8-Pin Grommet
One (1) 7-Pin Grommet
One (1) Instruction Sheet
PART NUMBER PART NAME
F5TZ-7A247-A TR Sensor Service Kit
OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage For 1992-94 Models, Basic Warranty Coverage For All Other Model Years
OPERATION DESCRIPTION TIME 950212A Perform Electronic 2.0 Hrs.
Transmission Diagnostics, Replace MLP/TR Sensor
DEALER CODING BASIC PART NO. CONDITION CODE 7F293 08

 

Ah, now this is familiar!

I get the same issue occasionally when I've been wading. Check the rear diff speed sensor - it is more likely this which is suffering from Water ingress. Since that sensor tells everything on the vehicle that relies on knowing the vehicle speed if its playing up there will be lots of other symptoms. Take off the plug and give it a good clean, pack it with some petroleum jelly and then reseat it. You may need to leave it disconnected for a while to dry it off if its really bad.