B2191 on Infiniti
Manufacturer-Specific Body Code (Nissan/Infiniti: Difference of Key / NATS ID Mismatch)
B2191 on Infiniti vehicles indicates manufacturer-specific body code (nissan/infiniti: difference of key / nats id mismatch). Au7o has documented this code across 1 Infiniti model — most commonly on QX50. B2191 is a manufacturer-specific body code. On Nissan and Infiniti vehicles it generally means 'Difference of Key' — the body control module and the NATS Intelligent Key failed ID verification, so the key the system read does not match a registered key. As a security/anti-theft fault, the immobilizer may prevent the engine from starting or the steering lock from releasing. On other makes the meaning could differ, so confirm against the specific service data. Typical repair costs on Infiniti range from $600 to $1,800, depending on the specific model and root cause.
Common Causes of B2191
- •Unregistered or incorrect key/transponder being used
- •Faulty Intelligent Key or transponder
- •Wiring fault between key slot/antenna and BCM
- •Failed key-slot or antenna amplifier
- •Body control module (BCM/NATS) fault
- •Interference or low key battery
B2191 on Infiniti by Model
Infiniti QX50(1 issue)
- Steering Wheel Lock / Ignition No-Start from Electronic Steering Lock Failure2014-2016
Infiniti/Nissan vehicles using the electronic steering column lock system have a well-documented failure mode where the vehicle will not recognize the lock state, leaving the car unable to start even though the battery and key fob appear normal. The issue is widely discussed across Nissan/Infiniti owner communities and tied to the steering lock control unit used on related FM-platform vehicles. Owners typically report a sudden no-start with the steering wheel locked or the ignition staying in ACC/ON behavior without cranking.
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View B2191 across all makes →Frequently Asked Questions
What does B2191 mean on Infiniti?▼
B2191 stands for "Manufacturer-Specific Body Code (Nissan/Infiniti: Difference of Key / NATS ID Mismatch)." B2191 is a manufacturer-specific body code. On Nissan and Infiniti vehicles it generally means 'Difference of Key' — the body control module and the NATS Intelligent Key failed ID verification, so the key the system read does not match a registered key. As a security/anti-theft fault, the immobilizer may prevent the engine from starting or the steering lock from releasing. On other makes the meaning could differ, so confirm against the specific service data. On Infiniti specifically, this code is documented across 1 model.
What causes B2191 on Infiniti vehicles?▼
Common causes on Infiniti: Unregistered or incorrect key/transponder being used, Faulty Intelligent Key or transponder, Wiring fault between key slot/antenna and BCM, Failed key-slot or antenna amplifier, Body control module (BCM/NATS) fault. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix B2191 on a Infiniti?▼
Repair costs on Infiniti range from $600 to $1,800, depending on the specific model and root cause.
Which Infiniti models have B2191 documented?▼
Au7o has documented B2191 on 1 Infiniti model: QX50.