A8: Computerized Engine Controls Diagnosis and Repair Controller Area Network, CAN Data Link Connector, DLC Diagnostic Trouble Code, DTC DTC ECM Output Devices Eight Step Diagnostic Procedure High Side Driver Control Immobilizer System Low Side Driver Control Making a Microchip MAP Sensor Ground Check O2 Sensor Volt Check Output Driver Control Retrieving Trouble Codes, Code Reader Scan Tool Scan Tool OBD II Scan Tools Scan Tools History Test O2 Sensor Thermistor Throttle Position Ground Check Throttle Position Sensor Throttle Position Volt Check Ref Signal Vehicle Speed Data Wide Band O2 Sensor