Hello everyone,

I'm having an issue with my 2007 g35x sedan that I've never encountered before. I drove it home after work one day, parked it, then left town for four days. When I got back into town and went to drive it I noticed the fob wouldn't open the doors. I used the key to unlock the door but then when I push the start button nothing happens at all. No dash lights, no stereo, no lights, no power windows, nothing. Just complete darkness. My first thought was maybe I left a light on or something and it drained the battery so tried to jump it off the wife's car but had no luck. I then took the battery out and brought it to AutoZone to have it tested. It tested good but was completely drained. They hooked it up to the charger and told me to come back in an hour. When I came to pick it up the battery was at 75% charge but still tested good. The guy said it should be enough charge to start the car and then have the alternator take care of the rest. I took it back and plugged it back in but unfortunately I got the exact same results. No power whatsoever. At this point I had no idea what to do so I did some googling/forum browsing. I found a lot of recommendations to check the fuse link attached to the positive terminal. I did one even better and I checked every fuse in the panel near the battery and the panel under the steering wheel. They all checked out and I even checked with a multimeter on the fuse link. I decided to go ahead and get a new fuse link anyways just in case I missed a blown fuse somehow and since they're relatively inexpensive around 20 bucks. Well lo and behold I got it hooked up and it made absolutely no difference. I have absolutely no idea where to go from here and can't dig anything relevant up on Google. Should I check the relays as well? The only relays I saw were in the battery compartment fuse panel and there were only two. Shift lock and horn relay. Could a relay even cause something like this? Any help would be greatly appreciated as I'm pretty much dead in the water here and have no idea where to go from here. Some possible relevant information. I do have a aftermarket 1000w amp/sub hooked up but never had any issues with it before and it's been installed 2+ years. Besides that I also noticed I was able to eject the cd from the stereo today but still unable to Re insert the cd or turn the stereo on.

Thanks again everyone for any tips.

 

Hate these kinds of problems!

How old is your battery? When you are unable to power things, does that include no cabin lights? Completely dead? I believe the audio system has a small CMOS battery in it to hold memory and it's possible that is enough to eject the CD even if it's sitting on the workbench. Maybe.

Since you seem to have traced every possible thing on the "+" side of the battery power, I would suggest taking a closer look at the "-" side. Carefully inspect the negative battery terminal connector, that main ground wire, and the area where it attaches to the chassis.

 

Yeah see if u have continuity from you negative terminal to the chassis.

 

Thank you for your response! Electrical problems are a pain haha. I will do some digging on the negative side when I get home and see if I can figure anything out. Your thought on the cmos is interesting also and I hadn't thought of that however I do not believe the cmos to be causing the eject to power because after I disconnected the negative side of the battery the eject button no longer worked.

 

The positive battery terminal is also a fusible link that holds the primary fuses to send power to all the other fuse boxes and systems of the car. I would start there.

EDIT: A good test of the systems is to see if you have brake lights since that's literally just a single circuit from the IPDM to the brake pedal switch, to the tail lights. If you don't have brake lights or headlights then you're not getting power to the IPDM in the first place.

 

Thank you for the reply and sorry I've been Mia for a few days. Had to take a break from this headache lol. I do have brake lights when I push the brakes. I took the car through the car wash a few days before this started to occur so I though maybe some water got to the IPDM but when I pulled it to look it looks perfectly fine. None of the fuses were blown and no signs on obvious corrosion. There is one relay in there though that I think I might try replacing. Does anyone know what it does? I'm at such a loss right now I'm basically just taking stabs in the dark. If that does nothing maybe I'll try to replace the IPDM.

 

Your "Power and Ground" FSM is here:
https://www.nicoclub.com/service-man...F2007%2Fpg.pdf
Scroll down below the display window and you can "click here to download a copy". That should help you trace electrical circuits. A wet IPDM or even the wiring harnesses connecting to it can certainly cause weird issues. What focused your attention on that one relay? I believe there are a few in your IPDM including one marked "Starter control relay". And according to the schematic; an "ignition" relay, AC and wiper relays, fuel pump relay, maybe even a horn relay. It's like your electrical system's main switchboard. If you needed to replace that entire unit you must find an exact part number match because each variation is specific to year, model, trans, engine, standard equipment, etc...

 

Thanks for the info! The main reason Im focused on that relay is because it's the only one inside my IPDM. I do believe there are other relays located behind the fuse box in the passenger compartment as well as 2 more in the fuse box in front of the battery. I'm not sure what the relays behind the passenger compartment or in the Ipdm do but the two inside the box in front of the battery are labeled horn relay and shift lock relay. The reason I'm going to replace the one from the Ipdm is because from what I understand that's what controls all electrical systems and not to mention I actually punched a little hole in the relay on accident while removing it so it should probably be replaced anyways.

 

Hey everyone just wanted to post an update. Unfortunately, I'm still having the same issue. I actually towed it to the dealership to try and figure out what was wrong with it. They said they could figure it out for 165 and then quote me on the parts and labor for the fix. We'll, after about 4 days I heard back from them and this is what they had to say. "FOUND VEHICLE DOES NOT HAVE ANY POWER OR LIGHTS COMING ON. BAT IS NEW. FOUND POS AND NEGATIVE CABLES WERE JUST SITTING ON TERMINALS AND NOT TIGHT. NEGATIVE CABLE IS MISSING BOLT. INSTALLED POS AND NEGATIVE CABLES AND STILL NO POWER.PUSHED VEHICLE INSIDE. CHECKED ALL FUSES INSIDE VEHICLE AND UNDER THE HOOD. ALL FUSES IN IPDM AND FUSE BLOCKS ARE GOOD. AT THIS TIME. FUSABLE LINK IS GOOD. DID FIND CLOCK, STEERING WHEEL ADJUST, AND SEAT ADJUST ARE WORKING." they then told me they would need additional time to diagnose and not to mention an additional 400 bucks so I just had my car towed back home. When I talked to the mechanic on the phone to see what the hell happened he told me that they had worked on it for 6 and a half hours so I think he's either lying, incompetent, or my car is actually in a pretty bad way haha. Anyways, in a last ditch effort to try to bring it back to life I bought a ipdm on ebay but unfortunately when I swapped it in im having the exact same issues. I've been looking at the service manuals that had been linked but unfortunately I have very little experience reading these electrical maps so I'm not to sure what I'm looking at or what I'm looking for. If anyone has any other suggestions It would be greatly appreciated. Otherwise, I will keep studying the manuals and hopefully figure something out.

Thanks everyone!

 

Hmm interesting 🤔


I wonder if the ECU could be responsible for all this?? Or does that just control the engine?

 

That would have nothing to do with the rest of the car not getting power.

Check your fusible link, it's the positive battery terminal and it's got a bunch of primary fuses in it. If any are blown/melted I would buy a new fusible link (they're like $25 and can usually be found at any parts house).

 

Thanks for the suggestion! Unfortunately, I already replaced the fusible link and am still having the same issues.

 

Make a detailed list of all the systems that DO work and all the systems that DON'T work and post them. That will help narrow down what is the actual culprit.

Push every button, use every function.

 

reading over everything. These cars definitely get weird when they get a little wet. Just speaking from experience. My sunroof leaked for a little bit. It�d soak my bcm and nothing good ever came from it. My car wouldn�t start. Interior had a mind of its own. No turn signals. They�re cheap on eBay. Only issue is you�d need your fob programmed to the car

 

Alright guys, here's where I'm at now. I bought a used bcm off ebay and installed it in and everything seemed to come back to life! The dash lit up, dome lights work. The only thing that doesn't work is it doesn't register my keys anymore which I what I expected. I had it towed to the dealership to have them reprogram the keys and the nightmare began all over again. They weren't able to program the keys. They said it's because the bcm wouldn't go into key registration mode. Now they want to reprogram the whole bcm I guess and it's going to cost me 500 bucks. Does anyone with experience with this know if this sounds right? Looking through the service manual I don't see any mention of this to replace the bcm. At this point I feel like I would rather just let them keep the ****in car then pay them the 100 bucks I already owe them not to mention the 500 bucks I will owe them if they attempt the repair whether it works or not.

Thank you everyone.