Ford Repair Questions? Ask a Mechanic for Answers ASAP
I am doing some checking,back soon with some ideas............
If the ABS lite is staying off and the speedometer never quits then we can assume all the wiring is good from the vss to abs module and cluster.If the vss was bad you would have alot more going on then just trans issues.The vss+ and- signal to the pcm and speed control servo is supplied from the instrument cluster on pins 2 and 7 from the cluster,wire colors pin 2 pink/orange, pin 7 gray/black.The PSOM(programmable speedometer odometer module) actually generates a new vss signal for the pcm and speed control.If you have speed control and it works (while the problem is occurring) then we can assume the psom is ok as well.If thats the case I would then proceed to go after the 2 wires I mentioned earlier.The first wire I would go after is the gray/black wire (circuit 679) between splice S246 and connector C185 at the PCM for the positive side.For the negative side I would check the pink/orange wire (circuit 676) from splice S216 through connector C202 and connector C185(pcm connector).I would also be sure to check for good continuity to chassis ground on this wire.If I didn't find an issue with the wires I would then overlay them with new wires pin to pin.
S246 Main harness, near T/O to speed control amplifier
S216 Main harness, near T/O to G200 (see diagram for location)
Its no problem, I really like going after these kind of problems.Keep me informed and hopefully we can get it fixed.
Good to hear back from you,
I still think a continuity check is in order from the psom to the splice and the ground side of the circuit both performed while bending and moving the wires that are accessible.If no faults found then I would be more comfortable replacing the psom.There is nothing wrong with the pcm.The voltage reading is only valid if the problem is occuring,if its not acting up at 4.37 volts then we know this voltage is acceptable even if its a little out of range...........Thanks for the $20