Diagnosis:
This guide aims to confirm the diagnosis of the infotainment system (Which I’ll refer to from now on as it’s proper name, the DCU or Display Control Unit) enters a failure mode that leaves you with functionally no display.
This applies to any vehicle on the repair kit compatibility list.
That failure mode typically presents itself with these symptoms, or variations of them:
- Center screen not working (black, but backlight on)
- Center screen showing only Nissan (Infiniti) logo
- Center screen going in a loop (shows logo/tries to start etc and then restarts)
- Center screen very slow, unresponsive touch, or random/infrequent reboots
- Any of these symptoms or more AND,
- Your backup camera still works when placed in reverse.
The last one is fairly key, as it shows that it’s not an issue with the display, it’s an issue with the operating system.
Breakdown:
To break down why it fails, the TL;DR is, the operating system is stored on a MicroSD card inside the DCU (a very cheap one). After enough time, this MicroSD card fails (due to a design flaw, and it’s cheapness). This causes the symptoms that we see people post about on the forums countless times, and usually results in DCUs that get replaced; sadly, often by Nissan for far too much money.
There are two copies of the operating system (OS) on the SD card, and a config file on a boot partition of the SD card that tells it which copy to boot off of. Switching to the second copy will get you up and running again, but it’s only a matter of time before it fails in the same way and you’re left with no backup to switch to.
So, you need to make your own backup– which is the goal of the primary guide (and the repair kit, which is a copy of a backup from my own repository).
Repair Kit Installation Instructions (All Vehicles)
Fix DCU Screen Failure | Free DIY Guide for Nissan, Infiniti
Why does the backup camera still work?
The backup camera normally works by sending a hardware interrupt signal to the DCU, which tells it to switch to a secondary video input– the input for the backup camera. This has to always work, which is why it’s a hardware interrupt. It has to switch the moment you go into reverse, no matter what is happening on your screen. So regardless of if your DCU is functional or not, as long as it’s not a hardware problem (like a failing screen, motherboard, or something else), as long as your backup camera works– it’s a very strong indicator that this will fix your problem.