My Lightning has has a rough idle for a while now, Ive changed plugs and checked everything there is to check. Had a friend come over with his 01 and swapped computers to see if maybe that was the problem.......neither truck would start with the others computer!!WTF??? The engines would just spin over but not start. They were the same CUX1 units,same year model trucks, and the build #'s are pretty close. Anybody have a clue? Hookes a scan tool up to both and eveything checked out except the O2 sensors. His graph was fine, my graph had the lines jumping all over the place! Any help would be GREATLY appreciated!

 

I think your keys are matched to your ecm's, so no start

 

Unless I am way off here, CUX1 was ONLY for 99 models, CUX2 was 2000 and there is another code for the 01/02 models.
My "99" has a CUX1 my budys "00" has a CUX2
Did you pull the negative from the battery and drain it by leaving the headlight switch on for about 10 minutes?

 

You can't swap PCMs. The system is networked to other modules and all have a specific ID. If you don't reset the system first, it considers it a "theft". When you install a new PCM, it must be configured to the vehicle using a Ford scan tool. Both trucks will have to pay a dealer visit now in order to start. Sorry for the bad news, but this topic has been covered here many times .

 

When you change the computer the truck will not start unless flashed for the PATS system.It probaly will not work if you switch back either.
The PCM and the PATS(Protective Anti-Theft System) work together.Anytime you switch YOU MUST REFLASH so the two systems can talk to each other.

VINNIE

 

Oh man, didnt know that. Both trucks restarted after installing the correct ecm's. They were hard to start though, they spun over for a little bit before starting. Everything seems to be ok now, maybe I have bad O2 sensors. Thanks for letting me know what was going on!

 

I figured that once you hooked up the other PCM and tried starting that some stuff would be uploaded to the PATS system.Luckily for you that did not happen.

VINNIE

 

PATS = Passive Anti Theft System

Actually the keys dont have to be reprogrammed into the HEC, nor does the processor have to be reflashed. What has to be done is a Parameter reset on the PCM, which at least requires a NGS. The main difference is that when you reprogram the keys, like when replacing a HEC, you have to have at least 2 keys present. But with a PCM swap, if a parameter reset is performed with a NGS or WDS, the same keys that are programmed into the HEC will continue to work.

Back when PATS first came out, it was possible to disconnect the battery, swap the processor, reconnect the battery and start the vehicle. Now i dont know if this only worked with a new (never used) processor that didnt require a parameter reset since it had never been used, or if it was the difference between the newer HEC or PCM integrated PATS and the older standalone PATS modules.

 

My bad (Protective instead of Passive). But I thought that is what the NGS did was reflash.If not the NGS then what is used to reflash(i thought a parameter reset was a refash) could be wrong.Learn something new everyday.

VINNIE

 

Vinnie, a parameter reset doesn't reflash anything, it just wipes out all the stored ID numbers. Each module has it's own ID value, and since all the modules share a databus network, they all communicate with each other. If you install a module with a different ID, the other modules don't recognize it and usually you get a P1260 theft detected code. You CAN reflash a PCM with the NGS, but that's a different procedure.

 

I learned my new thing for the day.I can go back to sleep now.

VINNIE

 

LightningTuner-Any idea why my O2 volt readings are all over the place? They are pretty much jagged lines up and down with long pauses at certain points. Heck one of them just stopped all together. My friends graph had nice up and down lines with no breaks or anything.

Thanks-
Rodney