The injector control module, also known as the injector driver module, is a “stepping stone” between the powertrain control module and the fuel injectors. It is used to prevent a large amount of voltage going through the powertrain control module. The injectors take a lot of voltage — more than a 12-volt battery can put out. The IDM amplifies voltage so that the injectors have enough to fire quickly.
The powertrain control module sends a signal to the injector control module. In turn, the injector control module or injector driver module fires the injectors. This module uses voltage to fire the injectors. If the injector driver module fails, the engine may run poorly, but in most cases, won’t even start. In addition, if a fuel injector fails, it fails to buzz. The rest of the injectors will also fail to buzz to protect the injector driver module.
Injector driver modules may be modified for higher voltage output, faster injection pulsation and longer injector on-time. Because the powertrain control module does not see what the injector driver module is doing, it doesn’t set a code. A stock injector driver module turns the injectors to fully on in 560 millionths of a second. A modified injector driver module could turn the injectors fully on in 440 millionths of a second, depending on the modification.
If the injector driver module is bad and has been properly diagnosed, you can purchase one here and replace it yourself.