Hey all, I'm at a loss. Swapped my known good 4.0 OHV out of my crashed 2000 4x4 into a newly acquired 2002 FX4 which had a blown head gasket on its 4.0 SOHC (but ran *just* well enough to get it on and off a trailer). Both manuals, swapped PCM appropriately, using the 2002 body side connector to the 2000 engine harness. At first the starter wouldn't fire, we were able to ground the starter relay from where it was trying to get ground from the computer through the body to engine connector but the 2000 doesn't have that pin. We've confirmed we have crank and spark, and that the fuel pump and its relay work by jumping it directly. When key is in the run the fuel pump relay immediately clicks on and off (not the 2-3 second prime we're expecting, a rapid double click, on-off). We think the computer is shutting off the fuel pump, maybe because of something with PATS (the 02 has it, but the 2000 didn't) but we can't seem to confirm that or think of anything else it could be. Can't check OBD2 codes because the OBD system doesn't seem to be getting the right handshake to initiate, we think that might also be related to PATS. Any help you gurus can provide is greatly appreciated.

 

2000 Ranger has PATS, 1999-2012 in Rangers with V6 engines, in 1998 it was a pay extra option so not many did, 2005 Rangers didn't have PATS, dispute with PATS maker

In 1999/2000 Rangers PATS was a separate module located above glove box
In 2001-2003 PATS was inside the PCM(engine computer)

To use the 2000 PCM in the 2002 Ranger you will also need its PATS module as they are a "matched set", also a PATS key from the 2000 Ranger
The 4 wire transceiver was the same in both years so 2002 can be connected to 2000 Module, its not a "matched" part in any year PATS system

PATS disables starter motor, fuel pump relay and fuel injectors
By-passing the starter motor, and even the fuel pump relay, is easy, the fuel injectors are the actual Theft Deterrent, know way to by-pass that unless you put on a carbeurator, lol

You could try a 1998 4.0l PCM, no PATS, but would need to change the 2 wire cam sensor/synchro, to the 3 wire version and run a 3rd wire, this was changed in 1999 with the addition of PATS