Strange electric issue - post rear view mirror destruction... related?

A quick glance in the wiring diagram (more info) for the circuit that powers that mirror would probably show you directly which fuse blew when child #2 boinked those wires together.

Alternatively, just testing all the fuses like an animal would probably get you the same place, just with more work and less diagram-glancing.

 

You have hit on one of the big reasons I prefer wiring-diagram glancing, indoors, in a comfy chair.

 

The first thing that occurred to me was that your kid managed to short out the CAN bus and in doing so it might have screwed up one of the chips that help pass the data from one device to another. That would account for your symptoms.

The second thing that sprang to mind was that you need to teach your kids not to touch wires. Any wires. At any time. They can be dangerous. They can be deadly. They can cause damage. It's not enough to say "the car's 12 volts, and that's safe". Kid's don't have a way to tell when it's safe and when it's 240V.

 

I don't think there are any CAN bus wires near the mirror on a 2009.

A later generation with a LKA camera up there, maybe. But not an '09.

 

The anti-glare garage door opener mirror has three wires. One goes to ground at the left side cowl panel, one is supplied by the 15 amp DOME fuse and one is supplied by the 7.5 amp ECU-IG fuse, which receives power from the IG1 relay.

The DOME fuse is in the underhood fuse box and the ECU-IG fuse is in the people compartment fuse box near the drivers left knee.

And yes, fuses can open following an over current situation, but still allow marginal contact of the element ends resulting in intermittent weak power.

my experience has been that flashing dash lights (like gear indication) are often caused by very low 12v being supplied to the circuit.......

personally, I would just tape up the exposed wires, replace both fuses and see what happens.

I would like to think that ANY tech that was informed of a transient like two wires touching would be bright enough to at least check the simple things first....but fools are everywhere...

 

Might not even be that exotic. Could have flat out blown one affected fuse, without disabling everything in the car as that tech seemed to think ... seems like maybe an underestimate of the number of different circuits there are in the car.

 

Always good to hear another success story!!!

Glad the car is back in action!

And if this person:

dealer intake person

needs lessons, have him give me a call.......

 

Sure, again; that's common for Uxxxx codes, which are communication fault codes. U0129 means "hey, I'm not able to talk to the brake ECU", and if there are two or more ECUs in the car that are all finding themselves unable to talk to the brake ECU, they'll all say U0129.

That's why the dealer really should not have just given a list of codes run together, but should have grouped them together by which ECU gave which codes. That's the way their Techstream software shows them, grouped by ECU. If this had been a trickier problem to diagnose, it might have been really useful to lay out the car's network diagram and know which ECUs weren't talking to which.

 

I joined and came to post here simply to say THANK YOU. This solution helped me a ton this AM.

I had hardwired a radar detector and dashcam to my rearview mirror, and knew I had touched the wires during testing before buttoning everything up.(I know, I'm an idiot) Put insulation sleeves and buttoned everything up, but could not figure out what was causing the Hybrid system error, etc., as the DOME fuse was fine.

Thank you thank you thank you.