Gear selector problem

[Jerry@tx]

My buddy is having a problem with his 7.3 auto. His car idles down or shuts off when he goes from park to rev. vice versa occasionally. But it starts up right away when you turn it over. It's only from rev to park. He had a recent sel and they checked it and said something about low voltage/ output in GR. He's running DP F-5 chip. Anyone have this problem?