DDEC-DETROIT. DIESEL. ELECTRONIC. CONTROL. R.J. HAMES, R.D. STRAUB, R.W. AM ANN DETROIT DIESEL ALLISON DIVISION, GENERAL MOTORS CORPORATION I I ... for system self- diagnostics and. combined with engine oil and water system sensors, offer engine protection diagnostics. ... 3|* while expanding capabilities for optimizing engine timing, torque shaping and speed governing.