Engine Management & ECU
The central electronic control unit responsible for receiving sensor inputs and controlling fuel/ignition actuators.
What is the ECU / Control Unit?
This sensor measures the volume or mass of air entering the intake manifold to determine required fuel delivery.
What is the MAF / Mass Air Flow Sensor?
The standard 16-pin connector located under the dash used to interface a scan tool with the vehicle network.
What is the DLC / Diagnostic Link Connector?
Standard fuel injection technology that sprays fuel into the intake runner or port rather than directly into the cylinder
What is Port Fuel Injection / MPI?
Engine management systems balance power and emissions by constantly adjusting this ratio.
What is the Air-Fuel Ratio / Stoichiometric Ratio?
This dual-sensor component monitors driver input at the foot pedal to command the electronic throttle body.
What is the Accelerator Pedal Position Sensor / APP?
Stored fault codes retrieved by a scan tool when the Check Engine Light turns on.
What are DTCs / Diagnostic Trouble Codes?
Gasoline Direct Injection operates at significantly higher system pressure using this specialized mechanical component.
What is the High-Pressure Fuel Pump?
Checking the ECU's power supply and ground points is essential to diagnose this condition where a scan tool cannot establish a link.
What is a No-Communication / Communication Fault?
A variable resistor whose internal resistance drops or rises based on intake air temperature or engine coolant temperature
What is a Thermistor / NTC / PTC Sensor?
This communication method sends data bit-by-bit sequentially over a single line, commonly used in automotive network buses.
What is Serial Communication?
The GDI operating mode that delivers a tightly grouped cloud of fuel right near the spark plug during the compression stroke for maximum fuel efficiency under light loads.
What is Stratified Charge / Stratified Combustion?
Engine management subsystems use this type of output component (like solenoids and motors) to alter engine operation physically.
What is an Actuator?
Unlike conventional mechanical linkage, this system uses an electric motor to open and close the throttle plate based on ECU commands.
What is Electronic Throttle Control / ETC / Drive-by-Wire?
The popular integrated circuit chip commonly used in OBD-II scan tool adapters to translate vehicle bus protocols to readable serial data.
What is the ELM327 Chip?
This GDI combustion mode mixes fuel thoroughly throughout the entire combustion chamber during the intake stroke for maximum power output.
What is Homogeneous Combustion?