2012 BRZ starts, but steering lock doesn't release (amongst other things)
 

Here's hoping for a Christmas miracle

I've had some battery issues with my 2012 BRZ recently - mostly caused by my aftermarket audio / nav bleeding energy while I'm parked. I disconnected everything and was still having trouble, so I started looking for a bleed elsewhere.

I've had every fuse out and back in, but at one point I started the engine with what I believed to be the 'bare minimum'. I've since discovered that a lot of fuses I thought less important actually feed into the ECM (e.g. STOP, BK/UP LMP).

My battery is definitely problematic (it sheds from 12v to 8.3v in a matter of minutes even with ground disconnected), but I have an Energizer jumpstarting kit, and I can use that to start the vehicle and it'll restart itself if done immediately after stop.

I discovered while trying to fix this that my OBD device draws power even with ignition off - so that's probably what's been causing the original battery problems.

Here's what systems work:
- central locking (although not properly because the driver's window can't close)
- start/stop
- the instrument cluster
- A/C unit (but not rear defog or mirror heaters)
- boot opening
- mirror fold and adjust

Here's what doesn't:
- power windows
- rear defog / mirror heaters (incl. the indicator light on the A/C unit)
- windscreen wipers / washers
- seat heaters (not my choice, bought a dealer demonstrator)
- steering lock release
- warning lights on dash for: engine, brakes (even with park brake off), TRC, VSC, ABS, steering lock.

OBDII reports no fault codes, with either Torque on Android or OBDAutoDoctor on OSX. I'm not certain I trust it. Yesterday it intermittently reported network issues, while also successfully reporting engine coolant temperature and fuel level. It's currently correctly reporting coolant temp, but not fuel level.

The vehicle responds to throttle as expected, although I obviously haven't tried to actually move it.

After poring over the wiring diagrams and looking for links between the non-functioning systems, I feel like I've done something to my ECU by starting up with fuses out. I've double-checked them all (the smaller ones, at least) in the footwell and engine bay. I'm about to triple-check them all.

I left the battery disconnected overnight and starting fresh this morning nothing has changed.

I've never attempted any flashing and don't have the device, so haven't done anything that way - only ever used OBDII in read (with an ELM327 and Torque etc.).

I've seen a fair few threads where the vehicle won't start at all but nothing like this - does anyone have any ideas?

(and yes of course I'm intending to replace the battery - that was what I was attempting to drive the car to the shop to do yesterday!)

Welcome, HazardousWaster, to our forum - :clap:

I'd suggest you run a check on the alternator and a load test on the battery, better yet, replace the battery.

Next, check all the fuses again and make sure they are put back where they belong.

Then I would disconnect anything you got hooked up to the OBD port.

Also, make sure your battery terminals are clean and put on tight.

I hope you get it sorted out soon.



humfrz

Thank you for encouraging me to go back to basics! On my third check, I saw I needed to replace ECU IG1, which explained everything.

I'm sure my battery will appreciate the terminal clean, and the voltage is 14.32V with the engine running.

Now I just have a check engine light to deal with and I can't connect to the ECU with OBDII (whackamole...).

Thanks again!