Need Diagnostician - Electrical Issue

2015 Tacoma Pre-runner

Hello,

I'm in desperate need of a Diagnostician. I have exhausted my knowledge regarding an electrical problem that SEEMS to be related to a dead battery - but maybe not. I went out to my truck to find it had the symptoms of a dead battery. Below is bulleted summary:
Initial Symptoms

• Engine would not turn over – did not even get the starter clicking sound.
• Dash lights do illuminate
• Tried to jump it with another battery – no go.
  • Before you ask – there was no cross connection, sparking, or excitement.

Replaced Battery (since it was 6 yrs old)

• Horn began to sound (good)
• Could not get it to stop using the key fob (bad)
  • Or at least it would not stay stopped
• Disconnected the horns for the neighbors sake.
• Later found that using the key to lock and unlock the drivers door would reliably stop it from wanting to blow the horn.
• Still will not start – see symptoms below
• Found that the 10A ETCS fuse was blown.
  • Replaced it
• Pulled each fuse and they are all good.

Current Symptoms

• Engine would not turn over – do not even get the starter clicking sound.
• Dash lights illuminate and odometer is visible.
• Hazard/Flashers work
• Headlights work
• Dome light works
• Turn signals do not work
• No power to the 12v sockets/cigarette lighter
• Radio will not illuminate or play
• The oddest one - Using the Key Fob
  • Pressing unlock - the lights flash twice as usual - BUT DOORS DO NOT UNLOCK
  • Pressing lock - nothing happens - no lights - no chirp - zilch

Do you think that I have a bad relay? And/Or could this be related to the security system. Uploading images of my fuse box under the hood... in case it is helpful.

Any insight would be greatly appreciated!

Thank you in advance,
Steve

 

I'd bet there's an aftermarket alarm somewhere that's gone haywire, take a peek under the dash on the driver's side for any suspicious wiring or modules that don't appear factory.

 

If this all started with a dead battery I would continue going down that route. If everything was fine and all of a sudden these things are popping up after replacing the battery look no further.

who knows maybe that fuse you found had been blown for a while now.

Remember KISS is often the best solution.

If you made any recent changes before this happened that would be good to know

 

Did you clean the battery terminals? Dirty terminals can cause symptoms of a 'no start'

 

The key here to me is the alarm going off when the battery was connected, the factory system won't do this but alot of aftermarket ones will and will also disable the starter when they are triggered.

 

To answer a few questions:

• This is an original alarm system.. the one with the red button on the dash left of the steering wheel.

• I cleaned the terminal connectors with a wire brush - nice and shiny.

• There have been no modifications made to the truck, other than I added a Redarc trailer-brake controller about 4-years ago.

Does anyone know how you would you go about checking the relays? This seems like the next logical step?

 

This is not OE. The OE system has no "button".
Just a flashing "Key" light on the center (middle) dash.

 

That's a dealer add-on alarm system, it's a Toyota accessory that is added onto the truck not a factory system.

I'd look into that first, I've had to unhook a few of them over the years for various issues.

Factory starting system diagram is also attached and starting system information & troubleshooting can be found in the post below.

https://www.tacomaworld.com/threads/2nd-gen-information-diagnostics.784008/#post-28042155

 

Regarding the Alarm.... It was on the truck when I purchased it - I have added a photo - it is the red illuminated button to the left of the steering wheel and is activated when I lock the truck with my key fob.

I also used to have a 4-Runner that had this exact same alarm system. So, I assumed it was factory - but I guess that the dealer could have added it.

 

I'd uninstall it.

https://www.tacomaworld.com/threads...-removal-that-little-red-devil-button.675634/

 

Thank you for the files - I will look at them this evening with a beer! Follow up Question - assuming that the starter is locked out by the alarm system - do you know if there is a shortcut to disable or reset the starter lock out?

 

The older ones you could just unplug the alarm ECU and effectively disable it but I need to look how this one is wired.

 

Turn the key to the ON position, and press the button 3 times.
see what happens.

 

OP, see the link below disarm info

That Alarm has been an issue for many

 

I was looking at a photo of a system pulled from a truck (attached below). Not sure if this is exactly the same type, but it does seem to have the little red button controller.

Two Comments at this point

• If this is the system that we're trying to remove/disconnect - I'm not sure I would want to even try it. If there was a way to disable it by disconnecting some wires or re-routing some wires - I would try that and be happy.
• If I were to try to find someone who had experience with this system to disable it, I guess it would almost have to be a dealer - but it looks like someone would flag $400+ to do it!
• Which component is the ECU?

 

The bigger box is the alarm ECU, the smaller box is the glass breakage sensor.
I'd be willing to be the relay is the starter interrupt relay.

I'd unplug the alarm ECU first and see what happens, that may be all you need to do.

 

Well, I finally found the install manual for it.
Maybe try the methods on page 8 ? See if any of those work?

If not......REMOVAL is my suggestion.
Just 'undo" what the install tells you to do.

https://toyotaparts.sparkstoyota.com/install/00016-35108inst.pdf

 

I posted the install manual above along with everything else I could find for the RS3200 system

 

I didn't even see it.
I was too busy trying to find a "bypass".

Evidently, there isn't one.
The only "bypass" is to remove that POS.

 

Everyone - Thank you so much for all of the information and insight. I really do appreciate it. I will start with unplugging the ECU - if that doesn't work. I'll progress to reviewing the Install Manual to see what I might be able to 'uninstall'.

Thank you again.

Next Morning in daylight: TinShooter - I tried the processes on Page 8 of the manual - nothing works from there - it assumes that the "lock button" on the key fob works (i.e. locks the doors and arms the alarm). In my case, only the "unlock button" seems to partially work (i.e. the flashers flash twice, but no chirp or unlocking sounds).