Hello,

I've had my M35x for about 4 years now and boy has it been a journey. This is the first car I've ever worked on and I've already replaced many components on my own (thanks to Youtube), so I went ahead and decided to replace the display screen as it had melted from being parked in the sun for too long. As I was replacing screens, I decided to unplug the battery so that there was no chance of getting electrocuted or short-circuiting something, and my dumb a** didn't realize I was supposed to remove the negative side before the positive.

As I was removing the positive terminal, the wrench I was using had touched some metal while also touching the terminal and created a spark and some smoke. Ever since that happened the car will not crank or start, however the rest of the electronics are functioning. My first instinct was that I had a blown fuse or relay, but after checking all of my fuses, switching out some relays, and even going to the junkyard to find replacement multi-fuses (50/30/30 and 40/30/30), it seems like it probably isn't a fuse or a relay... unless there's one I missed somewhere.

I've been doing some research and was thinking maybe I blew a fusible link (still not too sure what that is), or possibly need to replace the positive terminal altogether? I was also thinking, however, that if this was the case then wouldn't the car get no power at all?

CAN SOMEONE PLEASE HELP ME? I have errands to run and hate asking friends for rides all the time

The power surge seems to have led to damage resulting in a loss of memory. Three things are probably involved, severally or collectively: the intelligent key unit, the BCM, and the ECM, although since the rest of the electronics are functioning it's probably the ECM that's hard hit. Is your security indicator light blinking or just staying solid?

Costee wrote: ↑

Tue May 26, 2020 9:33 am

The power surge seems to have led to damage resulting in a loss of memory. Three things are probably involved, severally or collectively: the intelligent key unit, the BCM, and the ECM, although since the rest of the electronics are functioning it's probably the ECM that's hard hit. Is your security indicator light blinking or just staying solid?

My security light blinks as normal.

What's the status of the light when the key is inserted into the slot and ignition is turned to the On position?

Costee wrote: ↑

Tue May 26, 2020 10:28 am

What's the status of the light when the key is inserted into the slot and ignition is turned to the On position?

The light stays off.

I guess that's good news somewhat. The immobilizer seems intact. Some other electrical short is preventing the car from cranking. Normally, the first line of action is to attempt to run a scan on the car for possible error codes to enable some diagnosis. Good luck.

Costee wrote: ↑

Tue May 26, 2020 10:48 am

I guess that's good news somewhat. The immobilizer seems intact. Some other electrical short is preventing the car from cranking. Normally, the first line of action is to attempt to run a scan on the car for possible error codes to enable some diagnosis. Good luck.

I ended up calling a mobile mechanic to come and run a diagnostic on it. Will update the thread when we find the issue. Thanks for relieving a bit of my worries it sounds like it may not be a very expensive fix. Fingers crossed.

Costee wrote: ↑

Tue May 26, 2020 9:33 am

The power surge seems to have led to damage resulting in a loss of memory. Three things are probably involved, severally or collectively: the intelligent key unit, the BCM, and the ECM, although since the rest of the electronics are functioning it's probably the ECM that's hard hit. Is your security indicator light blinking or just staying solid?

Mobile mechanic came to take a look at it. Said the ignition control module was not receiving a signal from their diagnostic tool which is supposed to be able to start the car remotely. Should I go ahead and replace the ignition control module, do you have any tips or videos on how to do it, and am I going to have to get the key fob reprogrammed after swapping it out?

Thank you so much for your help.

I'm not clear what's meant by ignition control module. Would it be the steering lock unit or the intelligent key control unit? Was he able to pull any error codes? If yes post the codes.

I never knew it was a thing either. Here’s what I found on google about it:
“ The Ignition Control Module is a part of the ignition system. It manages the electrical current that is fed to the ignition coil in order for it to generate the right amount of voltage for the spark-plug to ignite the fuel mixture. ... In turn, the ignition control module sends the input to the ignition coil to fire it up.”

Didn’t mention any codes just an error message that stated the ignition module wasn’t receiving a signal.

Seems the guy used a cheap tool. When you googled did you search the item with specific reference to Nissan/Infiniti or even your model? I'm suspecting the I-Key unit.

Costee wrote: ↑

Tue May 26, 2020 1:58 pm

Seems the guy used a cheap tool. When you googled did you search the item with specific reference to Nissan/Infiniti or even your model? I'm suspecting the I-Key unit.

After doing a whole lot of research and watching various youtube videos, I am suspecting that I may need to repair or replace the IPDM. Now that I think about it, before this issue occurred I was having other problems as well. If I put the A/C up too high, it would shut off and I'd have to restart the car to get it to work again. If I had the car running and in park the tail lights and inside cabin lights would dim and brighten on their own. When I initially would press on the gas, the RPM's would go up, but it would take a little while for the car to start accelerating as quickly as it should... this was the worst while making a turn.

Do these all sound like symptoms of a failing IPDM?

All these certainly sound electrical and the IPDM could be a suspect. There is a short somewhere. You said you checked all the fuses. There are four fuse locations: the fuse block in the car; in the IPDM, and two other smaller fuse blocks facing the battery. Did you check all these?

Costee wrote: ↑

Wed Jun 03, 2020 11:12 am

All these certainly sound electrical and the IPDM could be a suspect. There is a short somewhere. You said you checked all the fuses. There are four fuse locations: the fuse block in the car; in the IPDM, and two other smaller fuse blocks facing the battery. Did you check all these?

Yes, I did. All are in good condition. I managed to remove the IPDM, open it up and inspect it, and didn't see any visual signs of damage. I'm having some trouble finding a replacement IPDM, I'm assuming it has to be from the exact same vehicle? But I did find a new ECM at the junkyard earlier and will be replacing that here soon to see if it could be the issue.

Yes, IPDM has to be from the same vehicle. Installing another ECM isn't plug & play; it will require programming the key. Does your steering lock disengage with the ignition on? I'm still in favour of a comprehensive diagnostic scan.

Quick question as I am still dealing with a No ACC/Start issue. The IPDM is just a fuse box basically right? When I did test the only relay terminal I didn't show power to was the ignition. Could I replace the IPDM without a reprogam? The dealer could not find what was causing issue & wanted $450 to keep diagnosing to find issue.

IPDM replacement does not require programming.

I ended up taking it to the shop and they got it started for me, didn't even charge me much either. However, the windshield wipers and A/C were not functioning. I replaced the IPDM with one I found on ebay and it fixed these issues. No programming necessary.