Question 1

What is the cheapest way to replace my 2012 Infiniti M37 smart key?

Accepted Answer

Call a mobile locksmith before you call the dealer. Infiniti dealers tend to quote significantly for smart key replacement on the M37, and that usually doesn't include coming to you. A mobile job with EZ Car Keyz covers the fob, the cut insert blade, and the programming in one visit, wherever the car is sitting. No tow, no multi-day wait for a VIN-ordered part, no separate line items for labor and programming on top of the fob price. Call for current pricing, but expect to save a good chunk compared to the dealer route.

Question 2

How much harder is all-keys-lost on the M37 compared to adding a spare?

Accepted Answer

Significantly harder, and owners on Nissan and Infiniti forums are pretty consistent on this point.

When you have a working key, adding a spare is an OBD programming session. The car cooperates. When every key is gone, the security module has to be accessed at a deeper level. A PIN has to be extracted, old key data has to be wiped, and new fobs have to be generated and registered from scratch. On the M37 this means proper diagnostic equipment and, depending on the situation, the right backup process before touching anything through OBD.

Forum threads on this platform warn repeatedly that the wrong tool or an incomplete process can leave the module in a state that's expensive to recover from. The job is absolutely doable with the right equipment. But the time, the complexity, and the cost are all higher than a simple spare.

Get a second key made while you still have one working fob. That's the real answer here.

Question 3

Do aftermarket M37 smart keys actually work, or should I buy OEM?

Accepted Answer

Quality varies a lot. Professional-grade aftermarket fobs built to OEM spec work reliably when programmed with the right tools. The cheap clone fobs sold on Amazon and eBay are a different story. Locksmiths report them arriving with incomplete internal electronics, loose button contacts, and cases that crack within months of normal use. Some won't pair at all. Infiniti dealers will frequently decline to program a fob not sourced through them, which leaves you stuck if the cheap fob fails post-purchase. We use fobs verified to work on the M37 specifically, not generic units that might fit the profile.

Question 4

My M37 shows a key warning but the car still starts. What is going on?

Accepted Answer

This comes up a lot with M37 owners. The car can still complete a start cycle even when the fob signal is marginal, especially if the fob was already inside the cabin when you hit the start button. What you're seeing is the system flagging a weak or inconsistent read, not a clean detection.

A few things cause this. Low fob battery is the most common. RF interference in certain parking structures or near certain electronics can also disrupt the read temporarily. There's also the contact issue inside the fob itself: if the battery isn't sitting flush against both contacts, the output is inconsistent rather than dead.

Don't ignore the warning and assume it will sort itself. A marginal fob that starts the car today can fail to unlock the doors tomorrow, and if it dies completely while you're away from the car, you're into a more involved service call than a battery swap.

Question 5

The door handle touch unlock on my M37 stopped working but the start button still sees the fob. Is the key bad?

Accepted Answer

Probably not. If the start button registers the fob cleanly and the other functions work, the fob itself is most likely fine.

Touch unlock on these door handles relies on a separate sensor in the handle. If it's isolated to one door, the handle sensor or the wiring to that door is the more likely cause. If both handles dropped out at once, that points toward the fob battery going soft or an antenna issue on the car side. Wipe the handle area, retest, and note whether it's one door or both before assuming anything about the key.

2012 Infiniti M37
Key Replacement - Save vs Dealer in Ventura County

Today, Not Thursday | Same-Day Service

2012 Infiniti M37
Key Options

Quick Service vs Long Wait

2012 Infiniti M37 Smart Key Replacement - Fast, Affordable & Professional

Save vs the Dealer on Your Infiniti M37 Key

Infiniti M37 Rapid Response, Done Right

Real Infiniti Speed, Real Reviews

Infiniti M37 Mobile Service FAQ

Infiniti M37 Key Service Areas

Infiniti M37 Key, No Waiting

2012 Infiniti M37Key Replacement - Save vs Dealer in Ventura County

Today, Not Thursday | Same-Day Service

2012 Infiniti M37Key Options