ECU-IG No. 1 Fuse Troubleshooting Advice

I have a 2010 5.7L Tundra that I've just been using as a tow vehicle, and I haven't had a chance to do anything that would require it for the last 10 months. During that time, I only went into it once about 3 months ago, and at that time the battery was pretty much dead. Otherwise, it has been sitting in my driveway. I know I should still be driving it every so often even though I don't "need" it, but... unfortunately it's too late for that. Before letting the car sit, I drove it monthly and never had any problems with it.

Now that I want to use it again, I replaced the battery, and now it keeps blowing the ECU-IG No. 1 fuse as soon as I turn the key.

The symptoms are:

• The stability control, ABS, SRS, TMPS, and brake (with the parking brake off) lights are all on. The 4LO/4HI lights are constantly flashing.
  
• The climate-control system and related features won't turn on
• The shifter will not go out of Park
• Simply turning the key on without starting the engine blows the fuse pretty much immediately

What still seems to work is:

• The engine starts and runs fine
• There are no active or pending DTC's, even after running the engine for a few minutes
  
• All lights (headlights, turn signals, brake lights, etc.) work
  
• The clock, radio, and power mirrors work
• The instrument cluster and all gauges work
• I can turn cruise control on, but obviously I can't test it without driving

I started looking through wiring diagrams to see what the ECU-IG No. 1 fuse feeds, and I counted about 3 billion circuits. I might be slightly off with that number, but I think it's pretty close. Annoyingly, they all seem to be in parallel, which makes the culprit difficult to identify.

Are there any common issues I should investigate first, especially related to a dead or recently replaced battery? Any tips for narrowing down what might be causing the short? While I have a lot of automotive experience, I'm guessing this could take hours or maybe days to troubleshoot due to the sheer number of circuits downstream of that fuse. Therefore, any advice is appreciated.

Thanks in advance.

 

After some troubleshooting, I found the steering wheel angle sensor is causing the short. After unplugging it and replacing the ECU-IG No. 1 fuse, everything is working again (besides the systems that require that sensor).

I found one other thread saying that melted wires going to the sensor are a "common issue". From what I can see, the wires going to mine are fine. Does anyone know what might cause a short like this? I'd hate to replace the sensor just for this to happen again.

 

Having the same issues. I removed an aftermarket (dealer added) car alarm thing. Karr Security, the problems started around then, but could be coincidence. I'll take a look at this but my fuse isn't blown with the same symptoms, except I cannot use the stereo and my climate control doesn't work at all. I have an 07 Crewmax Limited.


Interested to see if you found anything else.

 

For me, everything worked fine after I replaced the steering angle sensor. I took it apart to look for obvious issues, but I didn't see anything. I have no idea what caused the short.