How does ECU relay power work on diesel?
ECU relay power on diesel models (see diesel notes below) make a judgement call where to take the feed from, based on how much load will be on this feed. DBC have pretty much nothing on this, DBW have a fair bit more load but then you may decide to delete most of it. As per T6/5 fuel relay power on petrol engines, ECU relay power on diesel models.
What are the symptoms of a bad ECM power relay?
A bad relay may cause the vehicle to crank, but not start, or sometimes not even crank at all. 3. Battery drain or dead battery. A failed ECM power relay can also cause a battery drain or dead battery. If the relay shorts it can leave power on to the computer, even when the vehicle is turned off.
Can a DBC be used as an ECU relay?
DBC have pretty much nothing on this, DBW have a fair bit more load but then you may decide to delete most of it. As per T6/5 fuel relay power on petrol engines, ECU relay power on diesel models. Only in use on some engines, often either low load or for things that can be deleted.
What should I do if my ECU light comes back on?
Drive the car for at least 10 miles for the ecu to learn, if there is a problem with your vehicle then the check engine light will come back on and you can analyze the fault code that the ECM throws. These codes will guide you towards the root of the problem and you can begin replacing parts to try to fix the issue.
What to do if your ECM power relay is failing?
For this reason, if you suspect that your ECM power relay may be having an issue, have the vehicle inspected by a professional technician, such as one from YourMechanic, to determine if the relay should be replaced. The most popular service booked by readers of this article is Vehicle Engine Electrical Inspection.
What happens if the ECM fails on a car?
The fuel and ignition systems, as well as several other engine management functions, of many vehicles are controlled by the ECM. If the ECM or it’s relay fail, the entire engine management system will be left without power and will not function as a result.
What causes a battery to go dead on an ECM?
Battery drain or dead battery A failed ECM power relay can also cause a battery drain or dead battery. If the relay shorts it can leave power on to the computer, even when the vehicle is turned off. This will place a parasitic drain on the battery, which will eventually cause it to go dead.