Sounds to me like your brother got some wires grounded really badly. As a result it may have sent a bad signal to the ECU and you may have a combo of bad wiring and an ECU that is on the verge of failure.
I would take it in and have it looked at but I doubt they are going to touch the wiring at all....for that I would run over to the local stereo shop or pull a homie hookup and get the wiring redone.
Has he had any problems with smoke smells coming from under the dash or the smell of electrical flash?
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