Power Supply

BATTERY POWER, KEY ON AND ENGINE MAIN RELAY VOLTAGE SUPPLY INPUTS







The engine control module receives a number of power supply inputs. These inputs provide information as well as operating power for the engine control module.

- KL 30 - Constant battery power: The engine control module requires continual voltage supply from the battery to store system adaptation values and fault codes. It also monitors the voltage level of the power supply as an input signal. If the voltage value weakens below a certain threshold, the engine control module adjusts certain output functions to compensate for the lower voltage value. i.e.: modify pulse width duration of fuel injectors, modify dwell time of ignition, etc.

- KL 15 - Ignition Key On input: The ignition key on input informs the engine control module that the engine is about to be turned on. This input signal is often called the "wake up call". When received, the engine control module provides a ground for the engine control module relay causing the relay to activate.

- KL 15 - Engine Main Relay Power Supply: Once the Engine Control module relay is activated, the closed contacts of the relay provide the operating power for the control module as well as the system components.