Originally Posted by kscumminsdriver
Frankly, I don't understand all of the logistics of swapping over a 12valve wiring harness and ECM and what 24valve sensors you can retain, which ones have to be pitched in the garbage, which sensors from a 24valve can even be used with a 12valve ECM/PCM.... i have no doubt it can be done but then you're just adding more complexity to the Ppump swap.
that's why I say it would just be easier to swap a complete donor 12valve engine, harness and dash into a truck...
Don't need the engine, just the harness, PCM, and from what I'm finding out, the gauge cluster.
12 valve PCM controls the automatic transmission using the TPS/APPS. So I use a 12 valve TPS/APPS on the P-Pump swapped engine and hook it to my 47RE... Or not, I can go manual valve body.
On the 24 valve, the gauges are all controlled by the PCM. So I throw in a 12 valve gauge cluster and all appropriate sensors, wiring harness, etc.
p pumping your truck will make your check egine light be on for vp codes and possibly cam sensor depending on the year and map sensor. you can take out the check engine light bulb becuase it wont turn off. i dont see the need in swaping in a harness or 12v
I can't take the Check Engine bulb out, because there is no bulb. It's an LED soldered into the gauge cluster. Plus that doesn't make it stop throwing codes out the OBD2 port. I don't want to throw any codes. Hence why I want to swap in everything properly including 12valve PCM.
I want the PCM to say that everything's working good. I want the OBD2 readings to look legitimately like they would on a properly running 12 valve truck.
You can't pass emissions while throwing codes.