Contents
How many volts should a PCM have?
It should read at least 12.6 volts with the engine off, or 13.7 volts with the engine running. If it’s showing less than that, fully charge your battery and re-test. The reason this is important is that low voltage can cause certain sensors to fail, depriving your PCM of the input it needs to make correct adjustments.
Can battery damage ECU?
Disconnecting your car battery will not cause any permanent damage to your computer or ECU (electronic control unit), but it can have some adverse effects. Those include canceling your preset radio stations, forgetting learned shift points, and your car’s ideal fuel/air mixture.
What is ECM battery voltage?
It should be right around 14.5 volts and current will vary depending on load.
Does the PCM control the alternator?
The PCM sends a 5-volt, variable duty cycle signal to the terminal to control the alternator voltage set point.
Can you fix an ECU?
ECU repairs can be very expensive. The part alone can cost between $1,000 and $3,000, depending on the make and model of your vehicle. Fortunately, an ECU can be repaired or reprogrammed in many cases—thus preventing the need to actually replace an ECU.
Does the ECM control the alternator?
The ECM controls and is constantly working to manage different areas of the vehicle to ensure that the vehicle is working at its best. One of these areas is the charging system which is made up of the battery, the voltage regulator, and the alternator.
What kind of ground and voltage do you need for an ECU?
The internals of an ECU contain delicate microprocessors and many other components that rely on clean, sound power and ground. Here are some tips from Holley’s EFI program engineer Doug Flynn on how to get the proper ground and voltage connections for your EFI system.
How can I tell if my ECU is bad?
There is wiring that runs into the harness of the ECU where you can check the voltage amount. All you need to do is connect a voltmeter gauge to it. This device will be able to detect how much voltage is running through the ECU. If the voltage is 6 or less, then this is likely causing your ECU problems.
Do you need ground and voltage for EFI?
When installing a Holley or any EFI system to your vehicle, it’s imperative to have a proper ground and voltage for the system. The internals of an ECU contain delicate microprocessors and many other components that rely on clean, sound power and ground.
What do you need to know about an ECU?
An ECU has to deal with many variables when deciding the correct mixture ratio. These require a number of sensors to measure such variables and apply them to logic in the programming of the ECU to determine how to correctly compensate for them.