Trying to help a freind out. It's 94 K3500. Has a DSG relocated PMD on the intake. It had code 78,29,35,36. 78 was a bad WG sol. fixed 29 I think are loose glow plugs(they were so loose they were leaking compression. Neither code has returned. It has a mid range stumble and the SES light comes on for a second when stumbling and goes out. It throws a code 36 consistently when this happens. The code 35 has not returned. Truck seems to run good otherwise. Has 94k on it and GM did the IP a few years back. PMD ?? IP ? I pulled the PMD and tried tightening the transistors. He is coming to my house Sunday and I am going to try the PMD from the Burb to see if it goes away. What else could that be ?