I have a 98 F150 4x4 w/ E4OD. My problem is that once I get over 60-65mph the truck throws a code (no CEL though). The code is P1500, which is a bad signal that is coming from the speed sensor. The speed sensor has been replaced 3 times and the transmission is new. The dealership has struggle for 3 days but they said there is a service message for some trucks that were built in late 1997. Apparently the fuse/relay box under the dash will short out and cause a bad signal to the ECU. The problem is that they can't get their test equipment to reproduce the signal when testing at the fuse block. They said its a $165 part with $300-$400 in labor to replace. Has anyone ever had this problem?

 

The other part of the VSS sensor is the tone ring in the rear diff. Has the diff been opened and the tone ring checked out?

Adrianspeeder

 

Would that be the sensor on top of the pumpkin of the rear end? The rear end has been rebuilt within the last 2-3 years and probably only 15k miles added to the truck since then. Its a 9.25" LS axle.