Tech Feature: Dissecting The Control Module – PCMs, TCMs And BCMs

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We may often plunge headlong into trying to figure out what precisely among the myriad things that can go wrong with Electronic Controls presented by the various PCM, TCM and BCM devices inside our vehicle to cause No Crank, No Start and Module Failures... but lack a solid or firmer understanding of all three.

So perhaps getting under the skin of all three units "From 30,000 Feet" requires taking a huge step back to view the very elemental aspects of how these units cross - communicate and learning what precisely it is that we need to know to better understand how they *Tick* and how they *Tock*.

THIS Article attempts to provide that very information and is some Bedrock Instruction definitely worth reading, downloading and saving in our Mechanics' Libraries and applying to our Diagnostics:

Tech Feature: Dissecting The Control Module – PCMs, TCMs And BCMs – UnderhoodService

With the complexity of automotive electrical systems increasing steadily, manufacturers have developed troubleshooting trees and strategies to make it easier for technicians to diagnose problems. These steps and strategies are very helpful for technicians when followed, but they can also prevent...

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Some Tests to perform to determine if there is Protection from Damage to the ECM (PCM):

ECM Damage

Engineers have devised two strategies that can be called the “immune system” for the electrical system.

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