Error Code P1610 is defined as Lock Mode. This code is triggered when the starting operation is carried out consecutively for five or more times with an unregistered ignition key or fault key.

This error code is a manufacturer-specific trouble code, meaning it does not apply to all vehicles makes. Rather, it applies only to specific vehicle makes, such as Mitsubishi, Nissan, etc. Specification on the definition, troubleshooting, and repairs still vary from one make and model to another.


Nissan vehicles come with an immobilizer feature, it’s an electronic device fitted to the vehicle, keeping the engine from turning on and running unless the correct key is inserted. This prevents car theft, as the vehicle can’t be hotwired after entry has been achieved.

It comes with a microcircuit inside the key which is activated by a small electromagnetic field that induces current to flow inside the key body. This process allows the key to broadcast a unique binary code which is read by the vehicle’s PCM (powertrain control module, also known as ECM or engine control module in other vehicle makes) when turned. When the PCM determines that the coded key is both current and valid, the PCM will then automatically activate the fuel injection sequence.

This immobilizer function is called the IVIS or Infiniti Vehicle Immobilizer System, also known as Nissan Anti-Theft System or NATS. It consists of the special ignition key, antenna lamp located in the ignition key cylinder, body control module (BCM a.k.a. IMMU), the PCM and the security indicator lamp

Error Code P1610 happens when an unregistered or damaged key is used to start the engine five or more times consecutively, causing the system to lock, and the vehicle unable to be driven.

Common Symptoms

As with other error codes, this code triggers the Check Engine light and registers the code to the vehicle’s system. And since it’s a Lock mode code, the vehicle cannot be driven, as there will be no starting.

Possible Causes

There are a couple of reasons for this error code, namely:

  • Defective or un-programmed ignition key
  • Faulty IMMU (body control model)
  • Faulty PCM

How to Check

As said earlier, this code is triggered when the wrong or damaged key is used to start the engine for five or more times, consecutively. When this happens, disconnect the battery for about 30 minutes and then try starting the engine with a known registered key.

If the problem persists, then your key must be reprogrammed, and the dealer must erase the code. This means you have to take the vehicle to your dealer.

How to Fix

As said earlier, simply disconnecting the battery for 30 minutes and then trying to start again with the correct key will solve this problem. If the problem persists, then try the following:

  • Turn Off the ignition switch
  • Turn On the ignition switch using the registered key (do not start the engine yet). Wait for 5 seconds
  • Return the key to Off position
  • Repeat steps 2 and 3 twice (for a total of 3 cycles)
  • Start the engine

If the problem persists, take your vehicle to the dealership and have their certified technician reprogram your key and erase the trouble code from your system.