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Discussion Starter · #1 ·
For the last few days, my key fob hasn't been working and when I open the door, my dome light doesn't come on. The fob's light flashes when the button is pressed, indicating there's still some juice in its battery. And the dome light works when switched to ON.

Figured my car battery was dead, but it starts up just fine. Think I should have my battery tested? Or could there be an issue with a door sensor?
 

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If the car starts, the battery is OK. For the overhead light, you can test if the door switch is the problem by opening the passenger door. If the light still doesn't come on, the driver-side door switch probably isn't the problem. (The switch on the light should be in the middle position.)
 

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Discussion Starter · #3 ·
Opening the passenger side door does not make the dome light come on either. The switch is in the middle position as it should be.

Seems like I remember the fob never working if a door is ajar. If the sensor thinks the door is always open, the dome light should be permanently on, though. If the sensor thought the door was always shut, the fob should work.

Don't think it's a fuse, since the dome light does work if switched to the ON position.

Could it be a wiring issue in the door? I have a multimeter but I wouldn't really know what to check.
 

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Discussion Starter · #4 · (Edited)
Just realized my door locks don't work either. I checked fuses and they're all fine...

EDIT: Aaaand my parking brake (BRAKE) light is staying on. I didn't think that'd be related, but I'm reading that it could be the MCU...
 

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Under-dash fuse 10 (7.5A) supplies the multiplex control unit and the keyless receiver. That would be something easy to check. The MCU controls the operation of the dome light when the switch is in the middle position, but not when the switch is in the 'off always' or 'on always' position.
 

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Just realized my door locks don't work either. I checked fuses and they're all fine...

EDIT: Aaaand my parking brake (BRAKE) light is staying on. I didn't think that'd be related, but I'm reading that it could be the MCU...
I'm experiencing this exact same problem and I'm in need of some help. I recently installed an led interior light kit from exledusa and I'm sure that the culprit. Everything was working fine for about a week and I came outside from work and the door locks weren't working.

I've checked the under-dash fuses and even returned to the stock interior bulbs. Nothing has worked so far. Does anyone have an answer to my problem?:confused:
 

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Hey did you ever replace the Multiplex control unit and if so did it solve your issues? I'm having the exact same problems except on top of all that the A/C is also not working (There is no problem with the compressor as it works when directly manually wired up). Thanks in advance
 

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Yes, I replaced it not once, but twice because I think the first seller sold me his faulty one. However, it definitely is the solution to all the problems you are having I promise. My A/C was not blowing cold air and I thought it was a separate problem, but it isn't. The MCU supplies power to the compressor and I didn't know my A/C was working because the MCU went out in December when I wasn't using my cold air.

Anyways, its an easy fix, but can be a slight pain in the ass.
 

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Yes, I replaced it not once, but twice because I think the first seller sold me his faulty one. However, it definitely is the solution to all the problems you are having I promise. My A/C was not blowing cold air and I thought it was a separate problem, but it isn't. The MCU supplies power to the compressor and I didn't know my A/C was working because the MCU went out in December when I wasn't using my cold air.

Anyways, its an easy fix, but can be a slight pain in the ass.
Thank you very much for a quick response! I now feel comfortable moving forward in my search for one. Will be searching junkyards first, then online.

If you don't mind, where did you purchase your MCU's?
 
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