Engine Electrical
Electronic Control Unit
An electronic control unit, often called the ECU or engine computer, reads sensors and controls fuel, spark and other engine functions. We list 37 electronic control units from $81 to $848 for 1984-2023 vehicles, mostly from AC Delco and A1 Cardone, with fits for the Chevrolet Equinox and Camaro, Ram 1500 and 2500, Cadillac CTS and BMW 325i.
Shop electronic control unit by vehicle
Confirm the fault first
Engine computers fail less often than the sensors, wiring and grounds around them. Before replacing one, check fuses, battery voltage, ground connections and the connectors for corrosion or water. Signs that can point to the computer include no communication with a scan tool, an engine that cranks with no spark or fuel and no other cause, codes that report internal faults, and visible water or burn damage. A shop with factory-level diagnostics can confirm the fault.
Programming and part numbers
Many units need programming to your vehicle before the engine will run correctly, and some listings say programming is required. Some are flashable, which means a shop or dealer loads the software through the diagnostic port. Security systems may also need a relearn so the immobilizer accepts the new computer. Match the service or part number on your old unit's label, since the same model can use different computers by engine, transmission and emissions package.
Installing the unit
Choose your year, make and model and check the fitment table for engine, transmission and drive type. Disconnect the battery before unplugging the old unit and keep static away from the connectors. Check the pins for bent or corroded terminals. Remanufactured units from A1 Cardone are rebuilt originals and may need your vehicle's data loaded. Plan who will program the unit before you order, so the vehicle is not off the road waiting.
Electronic Control Unit questions
Does a replacement ECU need to be programmed?
Often, yes. Many units must be programmed with the correct software and your VIN, and some need an immobilizer relearn. Check the programming field on each listing and plan for a shop or dealer if needed.
How do I know if my engine computer is bad?
Rule out power, grounds, fuses and wiring first. Signs of a failed computer include no scan tool communication, internal fault codes, or a no-start with no other cause. A professional diagnosis helps avoid replacing a good unit.
Which part number should I match on an ECU?
Use the service or hardware number on the label of your old unit and compare it with the listing and fitment table. The same model can use different computers for different engines and options.