EN

Severity: Moderate Code type: Manufacturer-specific (Nissan)

Nissan P1610 Code: NATS Lock Mode (Immobilizer)

After repeated failed immobilizer checks, the Nissan ECM has locked itself and won't let the engine start.

At a glance

Severity: 3/5 – Moderate3/5

Severity: Moderate

Meaning
NATS Lock Mode (Immobilizer)
System
ECU & Outputs · Powertrain
Safe to drive?
No — stop driving
Typical repair cost
$0–$450
DIY difficulty
Easy

NATS, the Nissan Anti-Theft System, lets the engine start only after the key's transponder ID has been verified and the immobilizer unit (or the BCM on later models) has confirmed that to the ECM. If the engine is cranked five or more times in a row while that check fails, whether because of an unregistered key or a communication problem, the ECM goes into lock mode and stores P1610. From then on it refuses to start even with the correct key, until the lock is released. P1610 is therefore almost always a consequence: something else caused the failed checks, and those codes (often P1614 or P1612) are the real diagnosis. Nissan describes a simple release routine that often gets the car running again once the underlying problem is gone.

Try this first – 5-minute fix

  1. Charge the battery first Check battery voltage; below about 12.4 V at rest, charge it or connect a charger. A weak battery can make the ID check fail again right after you release the lock.
  2. Use one registered key on its own Take the original or a known-good registered key off the key ring, away from other transponder keys, fobs and access cards.
  3. Run the lock-mode release routine Ignition OFF. Turn the ignition ON with the registered key without starting and wait 5 seconds, then back to OFF and wait 5 seconds. Do this three times in total, then try to start.
  4. Still no start? Read the other codes If the engine still won't fire, P1610 is being caused by an unresolved fault. Read the ECM and BCM/immobilizer codes and follow P1614 or P1612.

How to read P1610

How to read P1610P11263104
  1. P Powertrain
  2. 1 Manufacturer-specific
  3. 6 Computer & outputs
  4. 10 Specific fault

Symptoms

  • Engine cranks normally but never fires
  • Security indicator on the dash stays lit with the ignition on
  • Problem started after several tries with a new, copied or spare key
  • Other immobilizer codes such as P1614 or P1612 stored as well
  • Battery going flat from repeated cranking

Possible causes

Ranked by how often each cause is behind this code (editorial estimate).

  1. Several start attempts with a key that isn't registered to this car (new, copied or from another vehicle) 30%
  2. Transponder in the key not being read (see P1614), causing repeated failed checks 25%
  3. Communication failure between ECM and immobilizer or BCM (see P1612) 18%
  4. Low battery voltage during cranking interrupting the ID check 12%
  5. ECM, BCM or immobilizer unit replaced or swapped without registration 10%
  6. Aftermarket remote starter or alarm interfering with the immobilizer 5%

Diagnosis step by step

Diagnostic flow: P16101Read every module2Watch the security indicator3Check battery and grounds4Release lock mode and test5Register keys if needed
  1. Read every module

    Read the ECM and the BCM or immobilizer unit with a Nissan-capable scan tool. P1610 tells you only that the ECM locked; the other codes explain why. Note whether U1000 or other network codes are present.

    Tools: OBD-II scanner

  2. Watch the security indicator

    With the ignition off, the security light blinking slowly is normal. If it stays on solid after the ignition is switched on, NATS has detected a fault. This quick check tells you whether you are dealing with an immobilizer problem at all.

    Tools: Flashlight

  3. Check battery and grounds

    Measure battery voltage while cranking; it should not dip much below about 9.6 V. Clean the battery terminals and engine ground so the modules stay awake through the ID check.

    Tools: Multimeter

  4. Release lock mode and test

    After fixing the root cause, clear P1610 with a scan tool if possible and perform the ON-5 seconds, OFF-5 seconds routine three times. Then start with the registered key.

    Tools: OBD-II scanner

  5. Register keys if needed

    If the key or a module is new, keys must be registered with a Nissan-capable tool and the car's security code. Registration usually erases all previously stored keys, so bring every key you want to keep.

    Tools: OBD-II scanner

Where the parts are

Charging system and control modules – P16101234567
Charging system and control modules
  1. 1Battery
  2. 2Alternator
  3. 3Engine computer (ECM)
  4. 4CAN bus
  5. 5Transmission
  6. 6Wheel speed sensor
  7. 7High-voltage battery

Repair options & costs

RepairDIY?Estimated cost
Lock-mode release routine Yes $0
Charge or replace 12 V battery Yes $0–$280
Program existing keys (locksmith or dealer) No $100–$300
New key cut and programmed No $150–$400
Register replacement ECM or BCM to NATS No $150–$450

Rough US estimates for parts and labor; shop rates vary by region. Not a quote.

Emissions / smog test impact

Depends

Immobilizer codes don't normally light the check engine light, but the vehicle obviously can't be tested until it starts. Clearing codes also resets readiness monitors, so drive for a few days before a smog check.

Frequently asked questions

Will disconnecting the battery clear lock mode?

Not reliably. The ECM remembers the lock. Use the ignition ON/OFF release routine or clear the code with a scan tool, and fix the reason for the failed checks first.

Why did lock mode happen after I bought a cheap spare key?

A copied or blank key isn't registered in the car's immobilizer. Trying it repeatedly counts as failed ID checks, and after five attempts the ECM locks. The key has to be registered with a Nissan-capable tool.

Can a dealer or locksmith fix this without replacing parts?

Often yes. If the only problem was an unregistered key or a weak battery, releasing the lock and registering the keys is all it takes.

Sources