I have a 2000 Ranger XLT 4x4 with 250,000 miles. I took it to the shop to have the heads redone due to idle and driveability issues. First thing they did was to hook it up to a scanner (not the parts house generic) and it could not pull data from the factory side of the pcm. It only showed N/A for all the data streams. The mechanic took another computer (not for this model) and hooked it up. It displayed data as expected.
Is this a known issue with the Ford PCM's? Can I have the computer reflashed? Or do I have to replace the computer?