How to Repair an Engine Computer Fuse that Fails

Each manufacturer designs their engine wiring systems a little differently, but one thing that stays the same is what an engine fuse supplies power to, such as the engine computer. This fuse is always under the hood inside the main fuse panel or PDC (power distribution center) and can be labeled as EGN1, EGN+ or ECM fuse to name a few. When this fuse blows it can be many things that can cause it, such as shorted wiring, but there are common causes for this occurrence which we will go over in this guide, also how to easily find and fix the problem.

How Does it Work?

The engine computer is responsible for supplying power to the various sensors, relays and servo motors needed to control the engine while it is running. Some manufacturers will have separate fuses for the injectors or the fuel pump, so if you are not sure how your vehicle is set up check your engine compartment fuse panel or ask one of our experts to help, it's free.

How Much?

A repair shop will charge between 2 to 4 hours of labor at $120.00 in most cases, and once the problem is found there will be an additional charge for the actual repair, plus parts.

What to Do?

1. To start, buy a box of fuses that match the engine fuse in amp rating such as 15 or 20 amps in a blade style fuse which will cost about $9.00 (US) at Amazon or the auto parts store. Then unplug all oxygen sensors, now replace the fuse and turn the key on. Have a helper watch the fuse as you plug in the oxygen sensor connectors in one at a time until the fuse blows, this will be the sensor that is shorted and needs to be replaced.

oxygen sensor connector

2. If none of these blows the fuse, unplug the ignition coils and try the experiment again by plugging the coils one at a time while the fuse is observed.

unplug ignition coils

3. Again if no results are gleaned do the same thing for the fuel injectors. These are the three main items that can cause the engine fuse to blow, oxygen sensors, ignition coils or the fuel injectors in that order. Nine times out of ten one of these three sets of items will be the problem. Simply replace the shorted part with a new unit and replace the fuse one last time and you are on your way.


Our certified technicians are ready to answer blown engine fuse questions for free. We hope you saved money and learned from this guide. We are creating a full set of car repair guides. Please subscribe to our 2CarPros YouTube channel and check back often for new videos which are uploaded regularly.

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