How Can I Fix My Car? Diagnosing a Nissan 370Z Immobilizer and Electrical Issue

Like many car owners, I’m usually reliant on dealerships for auto repairs. However, I’m currently facing a frustrating situation with my 2014 Nissan 370Z. The dealership has essentially said they can’t fix it, labeling my beloved car a $20,000 paperweight. Naturally, I’m skeptical and looking for guidance on how can I fix my car myself, or at least understand the issue better before seeking a second opinion. I’m sharing my detailed notes in hopes that someone with expertise can offer some insight into this perplexing problem.

The Immobilizer System Breakdown

About two and a half weeks ago, my car’s Vehicle Immobilizer System kicked in shortly after starting my morning commute. After driving just a short distance, around 200 yards, the intelligent key light illuminated, and then almost all my instrument panel readings went dead. While the engine was still running, there was a significant loss of power, making acceleration minimal. Upon returning home, the car wouldn’t turn off using the ignition button. I had to stall the engine manually using the clutch. Even after stalling, the ignition button remained in the “On” mode, and the interior lights and headlights were still functional. The key fob was still recognized by the system when I approached the vehicle. Adding to the confusion, a loud beep or buzz was emanating from the engine compartment. In a further attempt to shut down the system, I tried using the physical key in the slot, but it became stuck and required dealership assistance to remove.

Warning Signs Before the Major Failure

This complete breakdown wasn’t entirely without warning. On March 20th, I experienced a spontaneous illumination of both the ABS and skid warning lights while driving. However, after turning the car off and restarting it, these lights didn’t reappear. This incident felt eerily similar to a breakdown I experienced the previous year, prompting me to take note of it.

A Year Prior: Echoes of Electrical Issues

Looking back a year, the initial signs were intermittent and subtle electrical glitches that would resolve themselves after restarting the car. These occurred sporadically over about a month. First, the ABS and skid warning lights came on, mirroring the March 20th incident. Next, the radio and air conditioning cut out while driving, but functioned normally after a restart. The third, and most concerning, instance involved a complete electrical failure in the cockpit, except the engine continued to run normally. Pulling over and turning off the car led to a situation almost identical to the current immobilizer problem:

• The intelligent key light illuminated.
• The car would start but not turn off without stalling.
• Most of the electrical system was non-functional (radio, A/C, instrument panel).
• The car could be driven, but with severely reduced engine power (limp mode), moving at a crawl, before a radiator hose burst.

Following this, I took the car to the dealership for repair. They proceeded to replace or repair several components:

• Radiator hose
• ABS brake hydraulic unit
• Computer
• Engine Timing

After each repair, the core electrical issue persisted. Within days to a week after each repair, the same symptoms would return: electrical system failures, primarily affecting the instrument panel (both digital and analog) and the radio and A/C. The engine, however, continued to run normally.

Eventually, a final repair was performed:

• Relay fuse to the Velocity control Unit

This last repair seemed to resolve the problem completely, until now.

This detailed history outlines a complex electrical problem with my Nissan 370Z, culminating in the current immobilizer issue. Understanding How Can Fix My Car in this situation is proving challenging, especially with the dealership’s inability to diagnose or repair it. Any insights or suggestions on potential causes or diagnostic steps would be greatly appreciated as I navigate this automotive puzzle.