501 is vehicle speed sensor 1 performance.
Do you have good tires or are they worn?
Check wiring and the connections for the system...
PCM connector (black/black) 1 pin 34 & 35
Module Anti-lock brakes all pins 1 thru 47
All wheel sensors
Theory of Operation:
The vehicle speed sensor rationality is a continuous test that monitors the vehicle speed sensor for lack of activity.
The rationality will not run if a limp-in exists for MAP, Throttle Position, and Engine Coolant Temperature. If vehicle speed sensor is below a minimum threshold for a period of time after the vehicle is operated at a sufficient load, a failure will be indicated.
With the engine running, transmission not in park or neutral, brakes not applied, and engine rpm greater than 1500.
This code will set if no vehicle speed signal is received from the ABS Module for more than 11 seconds for 2 consecutive trips. Two Trip Fault.
Three good trips to turn off the MIL.
ACTIVE BUS OR COMMUNICATION DTCS
700 let's you know the EATX for the trans has a DTC code stored in it.
DTC PRESENT IN EATX CONTROLLER
This is an informational DTC letting you know that a DTC(s) is stored in the Transmission Control Module.
Erase this DTC from the PCM after all Transmission DTC(s) have been repaired.
Using a scan tool, read the Transmission Controller DTC and refer to the Transmission Category and perform the appropriate symptom diagnostic.