Car diagnostic computer codes are codes produced by the vehicle's PCM, or Powertrain Control Module. It's a rudimentary computer system which controls the vehicle's engine performance by receiving information from sensors attached throughout the engine and car and making changes accordingly. By using a Diagnostic Code Scanner attached to the PCM, mechanics can determine what's wrong with the vehicle.
The computer codes ranging from P0100 to P0199 have to do with sensors within the engine's intake, exhaust, and carburetor. They may indicate a problem with the mass air flow sensor, the oxygen sensor, the oil temperature sensor, or the fuel pressure sensor. In all these cases, the sensors are sending feedback to the PCM which is outside of normal threshold values, indicating that the sensor could be broken, or there could be a problem in the engine's functioning which would cause these values to be recorded.
This range of computer codes indicates a malfunction in the vital parts of the engine's combustion cylinders. There may be a problem with the fuel injectors, the combustion cylinders themselves, the injection pump, the turbocharger (if the vehicle has one), and the throttle/pedal position sensors.
This range of codes indicates problems with the engine's output and ignition systems. There may be a problem with the crankshaft, camshaft, ignition coils, or timing chain. Consequences of these codes could simply be faulty sensors, but are more likely the result of wear on the crankshafts and camshafts, damage to the transmission may result in one of these codes as well.
This range of codes has entirely to do with exhaust and emissions control. Because so much can go wrong with a catalytic converter, these codes indicate exhaust gases spilling out of the engine, water vapor in the catalytic converter, overheating, excess exhaust pressure, or a complete failure of the evaporative emissions control system.
This range of codes is related to electrical malfunctions. There could be a problem with the fuse box or electrical wiring, the idle control system, power steering, or cruise control could all be ailing.
