gen-tsx

I have a 2012 TSX wagon. I parked it today, and some time later, the alarm went off. Silenced it, and it came back, silenced it again. Then the headlights came on and stayed on. I started the car, and just about all the systems reported failures - ABS, Transmission, VSA, and probably more. The interior lights did not work, nor did the keyless entry. The headlights were turned off on the steering column control, but remained on after the car was turned off. I disconnected the battery and left it for a few hours. When I reconnected the battery, most systems came back without errors, except the following:

• Interior lights
• Radio and center console display. Climate control works, but there's no display of setpoint.
• Keyless remote
• Power locks - can lock all doors from driver's door, but can't unlock them. Also can't open rear hatch if car is turned off.
• Some 'memory' functions - it loses trip fuel economy and forgets that cruise was in use after it's turned off.

Can anyone help diagnose what's broken? I don't know how many computers it has or how functions are split up between them.

NBP04TL4ME

Not positive, but a suggestion - there have been reports that a dead or dying battery can cause multiple failures and/or odd behavior in our cars (across the Acura lineup). How old is the battery?
Are all of your battery connections solid? Battery cables are good at both ends?

gen-tsx

Thanks for the suggestion, but I'm afraid it's not likely. The battery is a two-year Interstate, and it had enough capacity to start the car easily after two hours of headlights being on. Connections seem clean and solid, but I will check the other ends of the cables. Lots of salt here in Vermont this time of year. Salt is evil.

This all happened this morning. I drove the car home today (a three hour drive) and we'll see if it freaks out again tonight.

NBP04TL4ME

Good luck and keep us posted.

Something else to check is to make sure the fuse block/box is clean and dry on the driver's left side foot well. A pillar leaks as well as bad windshield replacement seals have been known to allow water seepage to drip on the fuse block causing shorts. Maybe not too likely but it has been known to happen.
I know about the salt - I lived in New England for 50 years.

gen-tsx

The good news: Fuse boxes are clean and dry. No obviously blown fuses. Battery cable connections are clean, dry, and solid. Car starts and runs fine.
The bad news: Interior lights, power locks, and center console display don't work.
Fuse 17 on the driver's side (Accessory, key, lock) is fine.
I'm assuming that there's a computer somewhere that manages the things that aren't working. Yesterday's bizarre behavior supports the computer melt-down theory. Any suggestions of where to look next?

RTM

1st off, hope you are checking fuses with a meter, not your eye.

Working off a 2012 diagram
Interior lights are on fuse 16 under hood box (7.5a), which covers, map lights, overhead, and mirror lights. Footwell lights, etc etc. No computer involved in these.

Power locks are on several fuses, from the drivers under dash box. First is the big 60A under the hood (No3-4), we'll ignore it for now.
No 25 (15A) feeds the door lock relays. The coils to the relays come out of the Drivers MICU, but power to the actuators is on this fuse.

The MICU is powered off fuses (No 5, drivers dash, 7.5a, basically IG1 ignition on, and Under Hood No 15 (10a), which is probably the always on.

Console Display - The HVAC Audio display is on fuse 16, not the same fuse as first item above. No time to track this down.
My sheet says 17 is Drivers MICU, but it didn't come up in the above drawings.

So summary, looks like several fuses in play, I would suggest poking them all with a meter before we get to concerned about a computer going out.

gen-tsx

Thanks - just back from a 1500 mile trip with the car. Still runs fine, but all of the convenience features are still dead.
I haven't checked every single fuse and/or relay, but I have checked all the ones you listed (thanks again) as well as any others that seemed remotely possible. I *always* check fuses with a meter. I got burned once that way - never again. All good.
The other reason I'm thinking computer (MICU?) is that this started with the bizarre behavior of lights on, alarm going off, and errors on every system in the car. That doesn't translate to 'blown fuse' very well.

So - what is the MICU, what does it control, and where is it? I've found lots of discussion about MICU, but not so much for the 2012 generation TSX. Updated list of what works and what does not:
Working

• Engine, transmission, ABS, Cruise Control
• Headlights, tail lights, turn signals
• Climate control, but there's no display of setpoint. I think it also forgets the setpoint when turned off.
• Power mirrors
• Power seats
• Power locks, but only from driver's door with ignition on
• Rear hatch, but only with ignition on
• Sunroof

Not Working

• Interior lights
• Radio
• Center console display.
• Homelink (buttons are illuminated, but don't work)
• Bluetooth
• Keyless remote
• Some 'memory' functions - it loses trip fuel economy and forgets that cruise was in use after it's turned off.