Anti-theft red light on solid when key off

My red anti theft system light should blink when car is off. Mine stays solid and drains battery.

 

Your talking about the red key light next to the clock?

What year is your truck?

 

2008 Tacoma 4.0 V6

 

…and yes. The red light with the key. The truck was struck by lightning and after some electrical gremlins were fixed that were drawing the battery down. This remained.

 

Well about the only two possibilities are the board where the light is on or the Transponder Key ECU got fried.
Does the truck still start and run?

Unplug the hazzard switch assembly and check for 12v on Pin 6 (Violet-White), if you have 12v there with the key off the it's the Transponder Key ECU. If not then it's probably the Hazzard Switch Assembly.

 

I’ll give it a try. After lightening strike, I had to jump start it. It started and ran fine but it seized up my e brake cable and shifting cable. Also, when I took keys out of ignition, I had random dash lights on. Battery drained fast. Had a shop fix those issues, but this one seemed to stay. This and 4wd and 4 lo lights keep blinking and will not stop. Truck won’t switch into 4 hi or 4 lo.

 

Yea lightning can cause alot of damage and weird electrical issues, not uncommon for alot of electronics to get fried when a vehicle is hit.

We can diagnose that too.
https://www.tacomaworld.com/threads/4wd-system-operation-help-thread.742420/

 

Thank you! I’m actually watching that thread already. I checked the EE ground tonight. And the voltages on pin 18, 19, and 7 ant the JB. All were 0V. So I don’t think it’s a ground. Where is the 4x4 ECU located?

 

On the right side of the glovebox opening, everything on accessing it and testing is in the first of the thread I linked.

If you need anymore help let me know.

 

And do you possibly have a pic of where the key transponder ecu is? I’m reading it says behind the dash towards the center..but that’s not very helpful.

 

I do not, it's buried deep in the dash. I'm pretty sure the only way to replace it is to remove the dash.

I can look under mine tomorrow and see if I can find it and get a pic.

 

Ok. So I have 12 V on pin 6 with the key off. I tested pin 7 continuity with another ground just to make sure that was good 0 ohms there. So that seems fine. I removed the fuse for ECU-2 from the box under the hood and now reading 0.22 V at pin 6. Plugged hazard assembly back in without fuse and light is off. So that makes sense. So I wanted to see if the car would still start without the fuse in. And it did?!? The hazard assembly isn’t plugged in. The fuse is out. Is this immobilized even working?

 

I assume pin 6 is power to the whole hazard assembly so I just can’t cut that so the light goes away. Right? Assuming the hazards wouldn’t work nor the airbag stuff or clock.

 

With the car running, I have 12 V back on pin 6. But the fuse is still out?!? Maybe power coming from ignition once running? But if pin 6 is power to the whole assembly…that would make sense if power coming from ignition. So maybe it is just the light electronics of the assembly? So

 

I’m starting to put it together..not everything on the hazard assembly goes through the transponder ecu. Because with the fuse out and car off, the hazards still work. If that Pin 6 power is only for the light..and the car starts without it…I may just clip it so I don’t see the light. Nobody is stealing an 08 Tacoma with 154k miles on it. At least not in New Hampshire.

 

The ECU-B fuse is keep-alive power for alot of the modules, most also have an ignition power. You will have a bunch of warning lights with that fuse out and your keyless entry won't work.

Correct the Violet/White wire only controls the security light (see the wiring diagram).
I bet the battery drain isn't the LED but the fact that the Transponder Key ECU (and possibly other modules) are staying awake. If that's the case snipping the wire won't help you.

Do you have a meter that does amps that you can see what your draw is?

 

When the ship was done replacing some of the modules they said the parasitic draw was within spec. After I took it home from them, I let it sit in the driveway for two days and it was dead when I went to start it. That’s when I called them and they said it was within spec when it left. I didn’t ask what spec was. I do wonder if that’s because it hadn’t run a lot over the week it was at the shop. And then I just drove it home. So maybe the battery wasn’t fully charged. Seems to start okay now after sitting for one night. But I haven’t tried two nights again yet.

 

50 mA (0.05A) is the maximum allowable parasitic draw.
Easy to check by putting an ammeter in series with one of the battery cables.

 

I put my DMM in series with the negative terminal and cable the other day just to see and I saw 0.53 amps. But I also read somewhere I need to let it sit a while to let residual draws go away. Are these the proper setting on my DMM to try that again?

 

You need to move your red lead to the 10A port on your meter to measure current just don't forget to move it back because it's essentially a jumper wire in that setting.