What Causes a Control Module on a Vehicle to Go Bad?

A control module can prevent you from driving if it goes bad.

The control module of a vehicle is basically the computer that does the thinking for an engine's control system. It affects the functioning of things ranging from a vehicle's charging system to its transmission. This is why when the control module goes bad, the engine suffers functionality issues as well.

Voltage Overload

One of the main things that can cause a control module on a vehicle to go bad is voltage overload. This can occur when a short exists in the circuits of either a solenoid or actuator. Replacing the control module will do no good if these shorts are not dealt with as the replacement control module will experience voltage overload as well.

Water

Another thing that can cause a vehicle's control module to go bad is water. Circuits get shorted out and the control module's electrical connections are harmed from the corrosion that builds if water manages to reach the inside of the control module. This is why repairs are usually not even attempted on control modules that come out of flooded vehicles.

Vibration and Stress

Vibration as well as thermal stress has also been known to cause control modules to go bad. This is because they can cause tiny cracks to form in the control module's circuit boards. However, unlike water damage, this type of damage to a control module is repairable.

References

• AA1Car: Powertrain Control Module (PCM)