Last Updated: 05/08/2023 @ 07:15 am

Article: EddyMaxx

Over the past few months, our FX35 started to experience some odd behavior. When scanning the car for codes it would throw U1001 – Invalid or Missing Data for Primary Id. I noticed this happened about a week after a major rain day that ended up clogging and filling water inside the car (primarily driver side seat). I had to drain all the water out as it was like a little mini-pool. This is what I think caused the issue in the first place. So I sealed the area where I think the car would leak from on roof with silicone. I’m also going to check and clear the sunroof drain ports as this is a common problem with FX35. The car itself would actually drive OK but some issues were very risky such as driving with no wipers in case it rain or no AC in 100 degree weather.

I started searching online and couldn’t not find much helpful info. In fact, most threads that had a similar issue never posted an update on how it was resolved. Each day I did more research to try to find the fix. Randomly, I was watching a YouTube video on CEL Code U1000 and U1001. I happen to find a comment by user “Staten Island Euro Tech” on YouTube that put me in the right direction and helped resolve the issue. So I have to give credit to that user for helping me resolve this. Not only did I save a ton of $$$$$, I also learned a lot in the process. If you are reading this, hopefully this helps you resolve the issue. You can post a comment using FB below for any questions or comments.

Below is the list of the issues:

No Air Conditioning (AC Compressor Would Not Kick On)
Front Wipers would Not Work
Fans would come on and stay on once car was started
Headlights would come on and you could not turn them off
No High Beam
No Fogs Lights
CEL Code U1001 – Invalid or Missing Data for Primary Id

Order of things I did to troubleshoot:

When this first happened, I thought it was the wiper motor. So I bought a used one off eBay and it did not change anything. $40 Bucks
I bought a used IPDM because after reading about it, I thought this could be potentially the problem. Did not change anything. $80 Bucks
Replaced BCM and no difference. Issue still persisted. You also need to program this unit to your ECU. I have Nissan Datascan II to do this so it was pretty quick $80 Bucks
I almost bought an ECU but decided not to because the drive drove fine. My next step was to find all the ECU ground and sand them down. I didn’t do it but I will just to be proactive. Read a lot about re-sanding the grounding points online.
FINALLY!! Found a solid pointer to resolving the issue via YouTube video. I fixed the wires under the driver seat and finally resolved the issues. Overall, I spent $200 bucks on parts I did not need. I will either keep them as spares or put on eBay. I may very likely keep them as these are parts that are getting more difficult to find in good condition on eBay. But technically if you find this video just in time, it will cost you almost ZERO dollars to fix.

The Fix and Solution

You need to remove the driver side seat and lift the carpet. It’s literally just four 14MM bolts. Then you need to unplug the connector for seat and SRS airbag light. The airbag light will flash after this, so you need to perform the reset procedure which you can also find on YouTube. Very easy to do.

Underneath the carpet you will see two sets of wires under and insulated cap. 3 Red wires and 3 blue wires. Remove the cap and you will see all the wires are broken and corroded. You need to unify them together again.

You can see how badly the wires were corroded.

This is just to show how much of the carpet I needed to lift in order to find this. I also took the time to vacuum and clean up the carpet area. I don’t remember when was the last time this was done.

This entire area was flooded with water and this is what I think caused the corrosion and wires to break. I did add silicone around the windshield to stop more water from coming in.

Re-splice the wires together and secure them. Once you do this try testing out your wipers to ensure they work. If they do, then you can proceed them tightening everything up and cleaning the area.