10A INJ Fuse

I was wondering if anybody has some suggestions as I am almost out of ideas. I have a 2018 Toyota Tacoma V6 MT.

First going to a dealership is not possible in my situation.

The issue I have is the 10A INJ fuse pops during idle. The idle time is always different. Usually longer on if the vehicle has sit, the longer it will run before the fuse will pop.

So far, Toyota has suggested to replace the entire engine harness. Well, that was done and I still have the issue. It was then decided to change the lower fuel injector harness. That was done, but still have the issue. There is one more harness for the upper fuel injectors I have yet to replace and will order the part, but I am not hopeful. All 12 injectors test fine as well.

I have nothing aftermarket running through that fuse. The only aftermarket option on this truck is a remote starter, but it is not used at all during any of this.

Does anyone have any suggestions? At this point I have spent so much work and money in this, I am open for any suggestions.

I have attached a photo of a fuse panel diagram and circled the specific fuse that keeps popping.

I appreciate all the help.

 

Remove the remote start....if the problem continues then you need a wiring diagram to see what that circuit feeds to back trace and test at all the different junction points to find the short. Someone probably nicked a wire installing it. It’s always best to take the aftermarket crap out of the equation or continue firing the parts cannon at it your call.

 

When did it start happening? Can you pull up a wiring diagram and see what all that fuse supplies power to. Visual inspection to see if there is any evidence of rodents, previous crash damage.

Edit

And yes, pull the remote start out and then inspect the wires it has tapped into.

Edit 2

Stop going to that specific dealer.

 

I would also go talk to the service manager at the Toyota dealership and request a refund on the work that they've done since they've misdiagnosed your truck.

 

My guesstimate is the Remote Start...or the IG2-Main Relay

 

@caribe makaira is probably better at this than I, but I can't see how its anything with the IG2-Main relay

If it were I, I would try to physically follow the few wires that run from that fuse to the ECU and the Injectors. After you wring those carefully, I would put my money on a injector... But really I dont know

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[Edit], It might be worth it to see if you can see any weird parameters on techstream for any of the injectors

 

My money's on the remote start wiring or control box. It's common to connect to a coil for tach sense. Some remote starters don't require it, so if that's your issue, you may still be able to use your remote start by disconnecting that tach sense wire and insulating it or completely taking it out of the system (I'm being optimistic of course).

 

Tach sensing is pretty much controlled now through data module interfaced with the CAN Bus. Still could easily be the remote start, but I highly doubt they ran a tach wire to an injector or coil

 

I'm kind of drunk right now but I don't remember him saying exactly when it started. If it started right after installing the remote start I put my money on that.

 

Shitty installs use old inputs like coils or injectors. I doubt it as well.

10A INJ does power coils as well.

I'd simply remove the fuse, and check all coils for B+ terminals that have ground.

 

The type of hardware and what the unit is using has nothing to do with shitty installs.

And nothing is a direct short, either wise that fuse would instantly blow. Something’s either drawing too much amperage slowly off that circuit or it’s an intermittent short, meaning something is moving and then causing a short.


OP, I would remove the remote start first and see what happens. Leave it out for a week or so need be. Taking that completely out of the equation. If still blowing the fuse after that’s removed I would start moving harnesses around and see if I can duplicate it. Then start tracing the circuit and see if you can find any visible issues. If not then I would run a bypass wire and see if that works

 

Manual with a remote start? Where did you get it from? What extra wires are ran to make the remote start work? Most of the remote starts are plug and play but the manual requires splicing I believe

 

Fair enough, I thought it was consistent with idle.

 

Thanks everyone for the replies. I’ll add some further details to help out.

Remote starter was installed after purchased new. Now has 45000 KM on it. I can’t keep it idling long enough to force a duplication. Longest I had it running after replacing the lower injector harness was just over 30 minutes. Afterwards it’ll usually run for 5 or less minutes.

I live incredibly remote and fly in only so Toyota dealer support is non existent. Only one mechanic currently in the hamlet.

Thanks again for all the help. This has been incredibly daunting.

 

Here’s an update.

I have recently taken the truck back from the mechanic and parked it. Last night my friend and I poked around the truck and learned something new that the mechanic did not know.

When putting a new fuse in the INJ, it actually pops only when turning the key to ignition, not actually cranking the vehicle. It pops immediately now.

I unplugged the Blade AL remote start box from under the dash and it still pops.

 

With the fuse removed, verify continuity from INJ fuse pin2 to EA1 connector pins #14 then #15 [separate connectors from the fuse box, test the connector on the box, not the removed one] That one goes to the injectors.

 

And from removed IG2-Main Relay (difficult to remove) to removed fuse pin #1

 

My worthless 2 cents
It should be getting easier now. Whatever it is, sounds like it is pretty good short to ground now, and expect it must be at less than 1 ohm. I would pull the INJ fuse and check to see if its output is reading low ohms to ground. If so, go to the EA1 connector and see where the short to ground traces... Intermittent is hard to find, a dead short to ground should be much easier.

 

Just want to say, what an incredible collective of talented folks here trying to help. Good luck OP. It sounds like you're close. Please keep us posted.

 

Okay so we did this. There is continuity between the pins.

When we reconnect EA1 that is when the fuse popped. Now the problem we have is after 2 fuse replacements the truck is running again. Just unsure for how long. We are waiting until the fuse pops again to continue testing.