CODING, DIAGNOSTICS & UPGRADES
Modules explained
Today’s cars have become like a mobile network of control modules. These control modules operate everything from the braking system, the power-train, steering and suspension system to climate control, lighting, entertainment, communications and navigation. The technology is mostly incomprehensible to the average motorist, yet it provides all kinds of functions and capabilities that were not even on the radar a decade ago: things like Bluetooth connectivity, hands-free communication and email, automatic emergency braking, blind spot detection, adaptive cruise control, stability control, electronic steering and even key-less smart fobs that allow the vehicle to sense your approach, automatically unlock the doors for you and wake up the onboard electronics so you can be on your way safer with less to think about.
To make such wonders possible, automotive engineers have created specialized control modules for all kinds of applications. Many motorists are somewhat familiar with the main modules in a vehicle such as the Powertrain Control Module or PCM, which used to be referred to as the Engine Control Module (ECM) or Engine Control Unit (ECU) because it was the computer that controlled engine functions such as spark timing, fuel mixture and emissions. PCM serves as a more descriptive term because the PCM on many vehicles also controls the transmission, which is part of the powertrain System.
A Transmission Control Module (TCM)
would be a separate control module for the transmission. It interacts with the PCM or ECU to make sure the transmission shifts at the appropriate speed and load to allow every think to run as efficiently as possible.
The Body Control Module (BCM)
is yet another major module that usually handles multiple tasks ranging from lighting and other electrical accessories to climate control, keyless entry, anti-theft duties and managing communications between other modules. The functions can vary greatly depending on the year, make and model of vehicle, and even its list of extra options selected when brought new from main dealer.
This brings us to the “other” modules. These modules aren’t very well known and most people don’t know about them until one fails and they have to get it replaced. These modules have all kinds of strange and confusing acronyms as each car maker has come up with its own unique list of acronyms for the various modules they use in their vehicles.
Some of the Modules
Listing all of the vehicle specific submodules would take too long. Instead here’s a short list of “other” modules classified by what they do. Many of these modules have a single dedicated function to perform, so they are relatively simple. But others can be nearly as complex as a PCM. To make matters worse, most of these modules may be located virtually anywhere inside the vehicle. Space is tight inside today’s electronics-packed vehicles, so engineers are often forced to locate the module wherever they can find a spot that hasn’t already been taken by something else. Finding a module’s location often requires looking it up on an illustrated component guide or wiring diagram.
Some of these other modules include:
● ABS/traction control/stability control module
● Airbag (SRS) module
● Alarm module (or chime module) for anti-theft system
● Cruise control module (if not integrated within the PCM)
● Electronic steering module
● Fuel pump control module
● Injector driver module (such as FSD/PMD modules on GM diesel engines)
● Instrument cluster control module (which may be part of the cluster itself or a separate black box)
● Keyless entry module
● Lighting module
● Remote start/immobilizer module
● Suspension control module
● Transfer case module (4WD)
● Wiper motor control module
● Vehicle communication module
● Plus all kinds of “mini” modules for power windows, power seats, heated/cooled seats, power sliding doors, door locks, sunroofs, air flow control doors inside the Heating Ventilation Air Conditioning (HVAC) system, and so on.
One final comment about modules is this: You can’t tell much about a module’s condition or its ability to function by its external appearance unless it shows obvious signs of corrosion or damage (such as flood or fire damage, or physical damage from an accident). If there is no code that indicates the module has failed, a bad module is typically diagnosed by a process of elimination. Everything else is ruled out first (such as bad grounds, wiring faults, low voltage, bad sensor inputs, etc.) until the only remaining cause is the module itself. Many DIYers (and even some pros) don’t want to take the time (or don’t know how) to do the proper diagnostics, so they assume the problem must be a bad module because the module is the most complicated component in the system or circuit. That explains why electronic module returns are so high, and why so many modules that are returned under warranty have no fault found when they are tested by the supplier or re-manufacturer.
At Jaguar Land-Rover car key replacement, we are the best experienced coding and programing experts in the whole of the country. So if you would like the experts to repair or program, diagnose and upgrade your module, book in with us today.
