PCM swap help!!??

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03lq4HD
Posts: 2
Joined: Sun Apr 17, 2022 6:08 am

PCM swap help!!??

Post by 03lq4HD »

I have a 2003 1500hd lq4 6.0 4l80e 4x4, had pcm trouble but hav a 2wd 2006 gmc 4.8 4l60e parts truck. So I swapped the pcm, copied the tune from the original lq4 pcm to the new pcm and the truck is idling smooth, no misfires, BUT After a couple revs I’m restricted to 20% tps and the trans is not shifting on its own, pulling out in 3rd or 4th like it’s in limo mode, I selected 4l80e box while tuning, and disabled the VATs but still have security light on dash. Not real sure what’s going on? Any suggestions please
03lq4HD
Posts: 2
Joined: Sun Apr 17, 2022 6:08 am

Re: PCM swap help!!??

Post by 03lq4HD »

Just a little added info, I swapped the fuel pedal and TAC module from the truck that the Computer came from as well
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