"MY" understanding is , the ECM wont lock down , unless its a SKREEM issue..i maybe wrong? Did he try to turn over the engine with the battery connected backwards? Start at the key , with initiated ,does it send power out , tooooo? Sounds like he did the Stealership solution , throw parts at it. You may need to locate an actual DBRlll reader. Sounds like everyone's covered everything other than ECM ,TCU. Following to help , add what you find...