In this blog post, we discuss two different types of grounds, power grounds compared to signal grounds. You can find our basic grounding system information here.
Power Grounds
A power ground is a ground that runs something high current, like a motor or a pump. Some examples would be the radiator fans, ABS pump, or windshield wipers. Generally, these grounds come from directly the chassis or a large metal piece in the car.
Signal Grounds
A signal ground is a reference point for measurements taken from sensors, typically originating from the Engine Control Unit (ECU). A good example of a signal ground is the Throttle Position Sensor (TPS). This sensor provides a 0-5 volt output that allows the ECU to determine the position of the throttle, indicating how open or closed it is.
The Throttle Position Sensor operates at 5 volts, meaning that the signal sent back to the ECU from the TPS ranges from 0 to 5 volts, depending on the throttle's position. The ECU provides both signal ground and a 5-volt input to the sensor. The signal ground is crucial because it maintains a reference for ground, which is why it is often referred to as reference ground.
Why does it matter which ground type I use for my wiring?
Power grounds are used to ground high electrical current devices, which can generate a significant amount of noise on the ground circuit. This is why it is important to separate power grounds from signal grounds. If a power ground is connected to a signal ground, it can unintentionally introduce noise into sensitive components, leading to inaccurate readings.
For sensors, a dedicated signal ground is crucial to prevent electrical noise from interfering with the ECU. This ensures the accurate measurement of the sensor's position. Additionally, it is important to have a stable ground source; therefore, the component measuring the signal—most likely the ECU—should provide the ground as well. If the signal ground originates from a different component, it can alter the signal range and result in incorrect readings by the ECU.
A note about the iWire Grounding Kit
Our Grounding Kit is specifically designed as a power ground solution for lower current components related to the ECU. By providing a solid grounding connection from the intake manifold, where the ECU obtains its power grounds, we can enhance the signal grounds for the sensors it monitors. It's essential to have a clean input to the ECU so that it can filter signals accurately, ensuring a clean output as well.
