Subaru BRZ 2017 won’t start but crank with a new battery. Need Help!

[Tahz]

Hi All, I need on how to fix my car so 3 days ago before I left at work I moved my car to a shaded area to check the issue with my dash cam. My Dash cam Viofo A129 is hard wired and the red wire which is always hot is tapped to fuse backup lights and the yellow wire ACC is tapped to fuse power outlet No1. I did it to not drain my battery because before the red wire is tapped to brake lights and it drained my battery. So the dash cam is not always on. After fixing the wiring and when I am about to leave the car wonÂ’t start not even crank so I open the hood and inspect the battery and noticed thereÂ’s a lot of corrosion on battery. The battery is 5 years old. I called Triple A and he tried to jump start it but this time the car crank but wont start. the triple A told me he’s not sure about the issue. So I left my car at work and bought a new battery and the next day I replaced the battery and tried to start it but still same issue. Car Crank but won’t start. My co worker who knows about car told me that the fuel pump was not working when you turn the ignition to an on position. He said it should click and make a little sound if the fuel pump is working .Could it be something got damaged because of the battery went bad? Could it be the relay got messed up? I don’t have a tool to check if the relay went bad. So fast forward to that. I got it towed to the dealership at Subaru and they are still diagnosing it. Looks like they still not sure what caused it not to start. Could it be immobilizer? Anyone have the same issue? Please help. Thank you.

[RZNT4R]

Always start with DTCs.

Not likely to be the immobilizer, those things don't just unprogram themselves. I've seen immos fall into theft mode after a certain number of tries with a bad or incorrect key, but if you had done that and had the immo light illuminated on the dash you'd tell us right?

The car is already at the dealer so I don't know how much help we can be, but since the trouble arose after you touched it, assume you broke it. Look up the wiring diagrams of every circuit you touched, ascertain what works and what doesn't work, eliminate causes accordingly. If everything checks out, return to normal diagnostic workflow for a crank no start. Start with confirming the computer's intention through live data: fuel pump enabled? Injection time? Ignition? If the ECM demonstrates a willingness to run, find out what keeps it from happening: what fuse is blown, what output isn't working, what circuit is open, what component is defective that isn't allowing the computer's intention to turn into action.

[Tahz]

I know the fuses that i touch was under the driver side fuse area. There are relays there too where all the fuses are located right? It’s called Body Integrated Unit. Are these relay also related to Engine not staring like if one of the relay fails it will tell the engine not to start? I know when I tapped my my dashcam fuse red wire to backup lights it shared the same wiring with the 10A ECU IG1 fuse and relay IG no1 relay. ACC yellow wire fuse to 15A P/point No2 which shared the same relay name ACC1 relay.

[humfrz]

Originally Posted by Tahz

Hi All, I need on how to fix my car so 3 days ago before I left at work I moved my car to a shaded area to check the issue with my dash cam. My Dash cam Viofo A129 is hard wired and the red wire which is always hot is tapped to fuse backup lights and the yellow wire ACC is tapped to fuse power outlet No1. I did it to not drain my battery because before the red wire is tapped to brake lights and it drained my battery. So the dash cam is not always on. After fixing the wiring and when I am about to leave the car wonÂ’t start not even crank so I open the hood and inspect the battery and noticed thereÂ’s a lot of corrosion on battery. The battery is 5 years old. I called Triple A and he tried to jump start it but this time the car crank but wont start. the triple A told me he’s not sure about the issue. So I left my car at work and bought a new battery and the next day I replaced the battery and tried to start it but still same issue. Car Crank but won’t start. My co worker who knows about car told me that the fuel pump was not working when you turn the ignition to an on position. He said it should click and make a little sound if the fuel pump is working .Could it be something got damaged because of the battery went bad? Could it be the relay got messed up? I don’t have a tool to check if the relay went bad. So fast forward to that. I got it towed to the dealership at Subaru and they are still diagnosing it. Looks like they still not sure what caused it not to start. Could it be immobilizer? Anyone have the same issue? Please help. Thank you.

So, just let them figure it out -

If it was still sitting in your garage, I'd suggest you unwire the dash cam and put everything back like it was.