Replacement of the PCM (powertrain control module) in Jeeps is in great demand these days, because there seems to be a rather large rate of failure for these automobile microprocessors in the US.
So what is a PCM and what is its function in your Jeep?
The PCM, called the JTEC or Jeep/Truck Engine Controller, like its name suggests is positioned in the engine. This triple microprocessor is digital and pre programmed. The PCM controls the ignition timing, emission control, fuel systems, air-fuel ration, charging system, speed control, idle speed and air conditioning.
The PCM gets inputs from a number of sensors and switches and acts on the inputs to regulate the working of the engine. The programming is adapted to changing climatic conditions.
How well a vehicle performs is dependent on how good the powertrain is. Vehicles with automatic transmission are totally computerized and the computer will indicate when …