B2190 on 2008-2015 Nissan Pathfinder: NATS Antenna Fault Causes and Fixes

What's Unique About the 2008-2015 Nissan PATHFINDER

The 2008-2015 Pathfinder spans two generations, the R51 (2008-2012) and R52 (2013-2015), which used different ignition systems. The R51 typically has a traditional ignition cylinder with a NATS antenna ring, while the R52 uses a push-button start with an Intelligent Key slot that contains the antenna. However, both systems rely on a similar NATS antenna amplifier to read the key. Nissan issued a Technical Service Bulletin (NTB13-015B) that applies to all Nissans with an Intelligent Key slot, highlighting that this code is frequently caused by simple issues like key fob interference, a weak key battery, or even 🎬 Watch: How to start your Pathfinder with a dead key fob foreign objects in the key slot, not just a failed part.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Generation note: This range covers the end of the 3rd generation (R51, 2008-2012) and the start of the 4th generation (R52, 2013-2015). The R51 uses a NATS antenna ring around the ignition cylinder (Part # 28590-C9902 is common for this era). The R52 has an antenna amplifier integrated into the Intelligent Key slot (Part # 28590-3JA0A is common). The diagnostic principles are the same for both, involving checking the key, battery, and antenna circuit.

Symptoms You May Notice

• Engine cranks but will not start
• Engine does not crank at all
• Security indicator light on the dashboard is solid or flashing when trying to start
• "No Key Detected" or similar message on the instrument cluster
• Intermittent starting issues, especially in cold weather
• Key fob functions (lock/unlock) work, but the car won't start

Most Likely Causes

1. Signal Interference at the Ignition 🔴 High Probability As noted in Nissan TSB NTB13-015B, placing other electronic keys, fobs, or large metal objects on the same keychain as the Pathfinder key can block the signal. The TSB also notes that inserting something other than the Intelligent Key into the key slot can trigger this code.
   How to confirm: Remove the Pathfinder key from the keychain so it is by itself. Try to start the vehicle. If it starts, interference was the issue. Ensure the key slot is empty.
   Typical fix: Keep the vehicle key separate from other keys and electronic devices.
   Est. part cost: $0
2. Weak or Dead Battery in Intelligent Key Fob 🟡 Medium Probability
   How to confirm: Try starting the vehicle with a spare key. If the spare key works, the battery in the primary key is likely the problem. You can also insert the key fob into the key slot (if equipped) which can often start the car even with a dead fob battery, as this is a backup method.
   Typical fix: Replace the battery inside the key fob (typically a CR2032 or similar coin cell).
   Est. part cost: $2-$10
3. Faulty NATS Antenna Amplifier 🟡 Medium Probability The antenna is an electronic component that can fail over time due to age or electrical issues. Forum discussions among technicians point to this part failing and requiring replacement.
   How to confirm: After ruling out key and interference issues, a technician can use a diagnostic tool like CONSULT-III to check for a signal from the antenna. They can also test the power, ground, and signal wires at the amplifier's connector using a multimeter, following the factory service manual procedure.
   Typical fix: Replace the NATS antenna amplifier. On some models, this is a simple swap, while on others it may require initialization with a Nissan-specific scan tool.
   Est. part cost: $60-$150
4. Damaged or Unregistered Key ⚪ Low Probability
   How to confirm: Attempt to start the vehicle with a known-good, registered spare key. If the spare key works consistently, the original key's internal transponder chip may be damaged. The TSB also notes that a key issue can store a B2190 that will not clear until a good key is used.
   Typical fix: The damaged key must be replaced and the new key programmed to the vehicle by a dealer or automotive locksmith with the proper credentials and tools.
   Est. part cost: $150-$400

Rare But Worth Checking

• Wiring Harness Issue: A wiring issue between the NATS antenna amplifier and the Body Control Module (BCM) can cause this code. This could be a broken wire, a corroded connector, or a loose pin. A visual inspection of the harness near the ignition cylinder/key slot is a good first step.
• Faulty Body Control Module (BCM): In rare cases, the BCM itself, which processes the key signal from the antenna, can fail. This is an expensive last resort and should only be considered after all other possibilities, including wiring, have been exhausted. A technician in a forum noted that a BCM replacement is a common dealer suggestion, but the actual fault is often elsewhere.

Diagnosis Steps

1. Read all stored trouble codes from all modules with a capable OBD-II scanner.
2. Remove the vehicle key from any other keys or fobs. Try to start the engine.
3. If you have a spare key, try to start the engine with it.
4. Replace the battery in the key fob (e.g., CR2032).
5. If the vehicle has an Intelligent Key slot, insert the fob and try to start the engine. This is a backup method for a weak fob battery.
6. Visually inspect the wiring and connector at the NATS antenna amplifier (around the ignition cylinder or key slot) for any visible damage, corrosion, or loose connections.
7. Using a multimeter and the factory service manual, check for proper power (Battery voltage) and ground (continuity to chassis) at the antenna amplifier connector M21.
8. If power and ground are good, check the signal wire voltage between the antenna and the BCM. This step may require an oscilloscope for accuracy.
9. If all wiring tests pass, the NATS antenna amplifier is the most likely failed component.
10. If replacing the amplifier does not resolve the issue, further diagnostics on the BCM and associated wiring are necessary, which should be performed by a professional with a tool like CONSULT-III.

Parts You'll Likely Need

• NATS Antenna Amplifier (OEM #28590-C9902 (Common for R51); 28590-3JA0B (Common for R52)) — This is the component that the code directly identifies as faulty. After ruling out simple key/battery issues, this part is the most common cause of the failure.
  Trusted brands: Nissan (OEM)
  OEM price range: $80-$160
  Aftermarket price range: $40-$80
• Key Fob Battery (OEM #CR2032/CR2025) — A weak key fob battery is a frequent cause of intermittent signal loss, triggering this code. It's the cheapest and easiest first step.
  Trusted brands: Energizer, Duracell, Panasonic
  OEM price range: $5-$10
  Aftermarket price range: $2-$5

Related Codes That Often Appear With This One

• P1610, P1614, P1615 — These codes are also related to the NATS system, indicating a 'LOCK MODE' or a key mismatch. They often appear with B2190, pointing to a comprehensive failure in the key recognition process.
• U1000 — This is a generic CAN communication error code. It can appear alongside B2190 if the NATS antenna or BCM is causing communication disruptions on the vehicle's network.

Technical Service Bulletins (TSBs) & Recalls

• NTB13-015B: This is the primary TSB for this code on vehicles with an Intelligent Key slot. It states that DTC B2190 can be stored due to interference from other items on a keychain, an Intelligent Key issue (like a weak battery), a wiring problem, a foreign object in the key slot, or a fault in the key slot/antenna itself. It also specifies that the code may not erase until a known good key is inserted.

Platform-Specific Known Issues

• Owner Experience: Intermittent No-Start on 2011 Pathfinder: An owner on the NPORA forums described a 'crank no start' issue on their 2011 R51 Pathfinder. A contributor suggested the immobilizer system was the likely cause, specifically mentioning the antenna ring around the ignition lock as a potential failure point that would prevent the BCM from reading the key. This highlights that even with a traditional key, the antenna is a key failure point.
• Dealer Repair Saga for NATS light: On a Nissan Qashqai forum (a platform mate), an owner detailed a lengthy dealer battle with an intermittent NATS light. The dealer first replaced the antenna, which did not fix the issue. They later claimed a firmware update was needed for the new part, and then suggested replacing a different, second part. The issue persisted, eventually requiring a master technician from Nissan to investigate, showing how complex these issues can become even for dealers.

Mechanic-Grade Diagnostic Values

• NATS Antenna Amplifier Power Supply Voltage — expected: Battery Voltage. Failure: Voltage significantly lower than battery voltage indicates a wiring or fuse issue.
• NATS Antenna Amplifier Ground Circuit Continuity — expected: Continuity should exist (near 0 ohms). Failure: High resistance or an open circuit (OL) indicates a broken or corroded ground wire.
• NATS Antenna Coil Resistance — expected: Approximately 12.1 ohms. Failure: A reading that is significantly higher (open) or lower (short) indicates a faulty antenna coil.

Scan Tool Commands That Help

• CONSULT-II / CONSULT-III plus: Self-Diagnostic Result — This is the primary function used to confirm if DTC B2190 is active or past after attempting to start the vehicle with a registered key.
• CONSULT-II / CONSULT-III plus: C/U INITIALIZATION — This function is required after replacing the BCM or immobilizer unit to register the components to the vehicle. It often requires a specific PIN code.
• CONSULT-II / CONSULT-III plus: Key Registration — After performing C/U Initialization or when adding new keys, this procedure must be used to register all keys to the NATS system.
• CONSULT-III plus: Work Support — This menu contains various service functions and active tests that may be used to diagnose related systems or perform resets after a repair.

Wiring & Ground Locations

• M21 — The harness connector for the NATS antenna amplifier, located at the ignition switch cylinder (R51) or the Intelligent Key slot (R52).. This is the primary connector where voltage and ground tests are performed to diagnose the antenna amplifier circuit.
• M57, M61 — Ground points located on the left side of the dash.. The BCM, which controls the NATS system, relies on these grounds. A poor connection at these points can cause various issues, including communication codes and B2190.
• M79 — A ground point located on the right end of the dash.. This is another critical ground location for dash-mounted modules. Ensuring this ground is clean and tight is a key step when diagnosing complex electrical issues.
• BCM Connector (R52) — For the 2013-2015 R52 Pathfinder, the BCM is located behind the instrument cluster.. The wiring for the NATS antenna (key slot) runs directly to this BCM. Specific pins for HS CAN and ignition signals are located in the black 40-pin and green 40-pin connectors.

Real Owner Repair Stories

• Reddit user in r/Justrolledintotheshop (Nissan vehicle (model not specified, but behavior is identical)) — No start, loss of communication to half of all modules, no power liftgate, no windows.
  ❌ Tried (didn't work) Replacing the BCM and initial wire repair did not solve all the issues.
  ✅ What actually fixed it The root cause was a poorly installed aftermarket remote start system. The installer had created multiple shorts to ground, melting wires and destroying several control modules, including the BCM and BSM (Blind Spot Module). The fix required extensive wiring repair and replacement of multiple modules.

OEM Part Supersession History

• 28590-C9917 → 28590-C9901 — Part revision or manufacturer change.
• 28590-C9902 → 28590-C9918 — Part revision or manufacturer change.
  Heads up: Part 28590-C9902 is listed as a widely used immobilizer control unit/antenna for many Nissan models of the R51 era, including the Pathfinder.
• 28590-3JA0A → None found, but noted as discontinued by some vendors.
  Heads up: This part is the immobilizer control unit for the R52 Pathfinder (2013-2015) and other models with the Intelligent Key slot.

Model Year Variations Within This Range

• 2008-2012 (R51): These models use a traditional turn-key ignition with a NATS antenna ring (e.g., 28590-C9902) that fits around the ignition lock cylinder. Diagnosis involves accessing this component within the steering column.
• 2013-2015 (R52): These models use a push-button start system. The NATS antenna is integrated into the Intelligent Key slot in the dashboard (e.g., 28590-3JA0A). The TSB NTB13-015B is particularly relevant, as it addresses issues specific to the key slot.